John D. Louie, MD

All Publications

• Pulmonary interstitial lymphography: A prospective trial with potential impact on stereotactic ablative radiotherapy planning for early-stage lung cancer. Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology Ko, R. B., Abelson, J. A., Fleischmann, D., Louie, J. D., Hwang, G. L., Sze, D. Y., Schuler, E., Kielar, K. N., Maxim, P. G., Le, Q., Hara, W. H., Diehn, M., Kothary, N., Loo, B. W. 2023: 110079

  Abstract

  This prospective feasibility trial investigated pulmonary interstitial lymphography to identify thoracic primary nodal drainage (PND). A post-hoc analysis of nodal recurrences was compared with PND for patients with early-stage lung cancer; larger studies are needed to establish correlation. Exploratory PND-inclusive stereotactic ablative radiotherapy plans were assessed for dosimetric feasibility.

  View details for DOI 10.1016/j.radonc.2023.110079

  View details for PubMedID 38163486

• Efficacy and Safety of Trans-Arterial Yttrium-90 Radioembolization in Patients with Unresectable Liver-Dominant Metastatic or Primary Hepatic Soft Tissue Sarcomas. Cancers Testa, S., Bui, N. Q., Wang, D. S., Louie, J. D., Sze, D. Y., Ganjoo, K. N. 2022; 14 (2)

  Abstract

  Patients with liver-dominant metastatic or primary hepatic soft tissue sarcomas (STS) have poor prognosis. Surgery can prolong survival, but most patients are not surgical candidates, and treatment response is limited with systemic chemotherapy. Liver-directed therapies have been increasingly employed in this setting, and Yttrium-90 trans-arterial radioembolization (TARE) is an understudied yet promising treatment option. This is a retrospective analysis of 35 patients with metastatic or primary hepatic STS who underwent TARE at a single institution between 2006 and 2020. The primary outcomes that were measured were overall survival (OS), liver progression-free survival (LPFS), and radiologic tumor response. Clinical and biochemical toxicities were assessed 3 months after the procedure. Median OS was 20 months (95% CI: 13.9-26.1 months), while median LPFS was 9 months (95% CI: 6.2-11.8 months). The objective response rate was 56.7%, and the disease control rate was 80.0% by mRECIST at 3 months. The following correlated with better OS post-TARE: liver disease control (DC) at 6 months (median OS: 40 vs. 17 months, p = 0.007); LPFS ≥ 9 months (median OS: 50 vs. 8 months, p < 0.0001); ECOG status 0-1 vs. 2 (median OS: 22 vs. 6 months, p = 0.042); CTP class A vs. B (median OS: 22 vs. 6 months, p = 0.018); and TACE post-progression (median OS: 99 vs. 16 months, p = 0.003). The absence of metastases at diagnosis was correlated with higher median LPFS (7 vs. 1 months, p = 0.036). Two grade 4 (5.7%) and ten grade 3 (28.6%) laboratory toxicities were identified at 3 months. There was one case of radioembolization-induced liver disease and two cases of radiation-induced peptic ulcer disease. We concluded that TARE could be an effective and safe treatment option for patients with metastatic or primary hepatic STS with good tumor response rates, low incidence of severe toxicity, and longer survival in patients with liver disease control post-TARE.

  View details for DOI 10.3390/cancers14020324

  View details for PubMedID 35053486

• Evidence-Based Integration of Yttrium-90 Radioembolization in the Contemporary Management of Hepatic Metastases from Colorectal Cancer TECHNIQUES IN VASCULAR AND INTERVENTIONAL RADIOLOGY Wang, D. S., Louie, J. D., Sze, D. Y. 2019; 22 (2): 74–80

  View details for DOI 10.1053/j.tvir.2019.02.007

  View details for Web of Science ID 000467430100007

• Evidence-Based Integration of Yttrium-90 Radioembolization in the Contemporary Management of Hepatic Metastases from Colorectal Cancer. Techniques in vascular and interventional radiology Wang, D. S., Louie, J. D., Sze, D. Y. 2019; 22 (2): 74–80

  Abstract

  Hepatic metastases are common in patients with metastatic colorectal cancer and are frequently the most life-threatening source of morbidity and mortality. The contemporary management of patients with liver-dominant or liver-only metastatic colorectal cancer is characterized by resection of metastases when feasible and successive lines of systemic treatment regimens consisting of chemotherapy drugs and/or targeted biological agents. Yttrium-90 radioembolization has emerged as a promising liver-directed therapy for patients with unresectable colorectal cancer liver metastases (CLM). The integration of radioembolization into the current treatment algorithm for unresectable CLM is dependent on the line of therapy it is being considered and whether it is to be used alone or in combination with systemic treatment options. This article provides background information on the current management of CLM and uses this framework to discuss the existing data that define when and how radioembolization can benefit patients with CLM.

  View details for PubMedID 31079714

• Quantification of Activity Lost to Delivery-System Residual and Decay in Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Hoang, N. S., Khalaf, M. H., Rosenberg, J. K., Kwofie, J., Reposar, A. L., Wang, D. S., Louie, J. D., Sze, D. Y. 2018; 29 (12): 1672–77

  View details for DOI 10.1016/j.jvir.2018.07.011

  View details for Web of Science ID 000453341200007

• Quantification of Activity Lost to Delivery-System Residual and Decay in Yttrium-90 Radioembolization. Journal of vascular and interventional radiology : JVIR Hoang, N. S., Khalaf, M. H., Rosenberg, J. K., Kwofie, J., Reposar, A. L., Wang, D. S., Louie, J. D., Sze, D. Y. 2018

  Abstract

  PURPOSE: To measure the decay activity loss and delivery system residual activity loss of yttrium-90 (Y90) radioembolization treatments across resin and glass microsphere activities.MATERIALS AND METHODS: For Y90 administrations between December 2009 and June 2017 at the study institution, the prescribed activity, prepared activity, and delivered activity were recorded. Six hundred sixty-two administrations were reviewed-345 glass (0.21-8.52 GBq) and 317 resin (0.18-3.28 GBq). Twenty-five patients (all resin) were excluded for arterial stasis or catheter clogging. The percentage and actual losses of activity lost to decay and to delivery system residual were calculated for glass and resin microspheres.RESULTS: The median time between activity premeasurement and administration was 2.20 hours, resulting in a median activity lost to decay of 0.030 GBq or 2.35%, with no significant difference observed between glass and resin despite differences in preparation (P= .0697). Resin showed significantly higher activity lost to delivery system residual than glass (0.039 GBq vs 0.010 GBq, 3.01% vs 0.61%, P < .001). The percent activity lost to residual varied with activity prepared, with a maximum of 20.1% and 16.2% for the smallest activities of resin and glass, respectively.CONCLUSIONS: Residual activity loss differs between glass and resin microspheres. For resin microspheres in particular, percent residual activity loss increases with lower prepared activities. Protocols for activity calculation and preparation, patient dosimetry, and regulatory compliance must take these losses into consideration prospectively.

  View details for PubMedID 30316674

• Clinical Trigonometry: Right Hepatic Trisegmentectomy After Radiation Trisegmentectomy for Hepatocellular Carcinoma DIGESTIVE DISEASES AND SCIENCES Titan, A. L., Devereaux, K., Louie, J. D., Poultsides, G. A. 2018; 63 (6): 1419–23

  View details for PubMedID 29119415

• Determining the Optimal Number of Core Needle Biopsy Passes for Molecular Diagnostics CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Hoang, N. S., Ge, B. H., Pan, L. Y., Ozawa, M. G., Kong, C. S., Louie, J. D., Shah, R. P. 2018; 41 (3): 489–95

  Abstract

  The number of core biopsy passes required for adequate next-generation sequencing is impacted by needle cut, needle gauge, and the type of tissue involved. This study evaluates diagnostic adequacy of core needle lung biopsies based on number of passes and provides guidelines for other tissues based on simulated biopsies in ex vivo porcine organ tissues.The rate of diagnostic adequacy for pathology and molecular testing from lung biopsy procedures was measured for eight operators pre-implementation (September 2012-October 2013) and post-implementation (December 2013-April 2014) of a standard protocol using 20-gauge side-cut needles for ten core biopsy passes at a single academic hospital. Biopsy pass volume was then estimated in ex vivo porcine muscle, liver, and kidney using side-cut devices at 16, 18, and 20 gauge and end-cut devices at 16 and 18 gauge to estimate minimum number of passes required for adequate molecular testing.Molecular diagnostic adequacy increased from 69% (pre-implementation period) to 92% (post-implementation period) (p < 0.001) for lung biopsies. In porcine models, both 16-gauge end-cut and side-cut devices require one pass to reach the validated volume threshold to ensure 99% adequacy for molecular characterization, while 18- and 20-gauge devices require 2-5 passes depending on needle cut and tissue type.Use of 20-gauge side-cut core biopsy needles requires a significant number of passes to ensure diagnostic adequacy for molecular testing across all tissue types. To ensure diagnostic adequacy for molecular testing, 16- and 18-gauge needles require markedly fewer passes.

  View details for PubMedID 29279975

• A Novel High-Resolution Magnetic Resonance Imaging Protocol Detects Aldosterone-Producing Adenomas in Patients with Negative Computed Tomography. American journal of hypertension Raber, I. n., Isom, R. T., Louie, J. D., Vasanawala, S. n., Bhalla, V. n. 2018

  View details for PubMedID 29648568

• Recommendations for radioembolisation after liver surgery using yttrium-90 resin microspheres based on a survey of an international expert panel EUROPEAN RADIOLOGY Samim, M., van Veenendaal, L. M., Braat, M. A., van den Hoven, A. F., Van Hillegersberg, R., Sangro, B., Kao, Y., Liu, D., Louie, J. D., Sze, D. Y., Rose, S. C., Brown, D. B., Ahmadzadehfar, H., Kim, E., van den Bosch, M. J., Lam, M. H. 2017; 27 (12): 4923–30

  Abstract

  Guidelines on how to adjust activity in patients with a history of liver surgery who are undergoing yttrium-90 radioembolisation (90Y-RE) are lacking. The aim was to study the variability in activity prescription in these patients, between centres with extensive experience using resin microspheres 90Y-RE, and to draw recommendations on activity prescription based on an expert consensus.The variability in activity prescription between centres was investigated by a survey of international experts in the field of 90Y-RE. Six representative post-surgical patients (i.e. comparable activity prescription, different outcome) were selected. Information on patients' disease characteristics and data needed for activity calculation was presented to the expert panel. Reported was the used method for activity prescription and whether, how and why activity reduction was found indicated.Ten experts took part in the survey. Recommendations on activity reduction were highly variable between the expert panel. The median intra-patient range was 44 Gy (range 18-55 Gy). Reductions in prescribed activity were recommended in 68% of the cases. In consensus, a maximum DTarget of 50 Gy was recommended.With a current lack of guidelines, large variability in activity prescription in post-surgical patients undergoing 90Y-RE exists. In consensus, DTarget ≤50 Gy is recommended.• BSA method does not account for a decreased remnant liver volume after surgery. • In post-surgical patients, a volume-based activity determination method is recommended. • In post-surgical patients, a mean D Target of ≤ 50Gy should be aimed for.

  View details for PubMedID 28674968

• Yttrium-90 Radioembolization for Unresectable Combined Hepatocellular-Cholangiocarcinoma (vol 40, pg 1383, 2017) CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Chan, L. S., Sze, D. Y., Poultsides, G. A., Louie, J. D., Abdelrazek Mohammed, M. A., Wang, D. S. 2017; 40 (10): 1657

  View details for PubMedID 28534185

• Yttrium-90 Radioembolization for Unresectable Combined Hepatocellular-Cholangiocarcinoma. Cardiovascular and interventional radiology Chan, L. S., Sze, D. Y., Poultsides, G. A., Louie, J. D., Abdelrazek Mohammed, M. A., Wang, D. S. 2017

  Abstract

  Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare mixed cell type primary liver cancer with limited data to guide management. Transarterial radioembolization with yttrium-90 microspheres (RE) is an emerging treatment option for both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. This study explored the safety and efficacy of RE for unresectable cHCC-CC.Patients with histopathologically confirmed cHCC-CC treated with RE were retrospectively evaluated. Clinical and biochemical toxicities were assessed using the Common Toxicity Criteria for Adverse Events v4.03. Radiological response was analyzed using the Response Criteria in Solid Tumors (RECIST) v1.1 and modified RECIST criteria. Survival times were calculated and prognostic variables identified.Ten patients (median age 59 years; six men, four women) with unresectable cHCC-CC underwent 14 RE treatments with resin (n = 6 patients) or glass (n = 4 patients) microspheres. Clinical toxicities were limited to grade 1-2 fatigue, anorexia, nausea, or abdominal pain. No significant biochemical toxicities were observed. Median overall survivals from the first RE treatment and from initial diagnosis were 10.2 and 17.7 months, respectively. Six of seven patients with elevated tumor biomarker levels before RE showed decreased levels after treatment (median decrease of 72%, range 13-80%). Best hepatic radiological response was 60% partial response and 40% stable disease by modified RECIST, and 100% stable disease by RECIST v1.1. Poor performance status and the presence of macrovascular invasion were identified as predictors of reduced survival after RE.RE appears to be a safe and promising treatment option for patients with unresectable cHCC-CC.Level 4.

  View details for DOI 10.1007/s00270-017-1648-7

  View details for PubMedID 28432387

• The Role of Dual-Phase Cone-Beam CT in Predicting Short-Term Response after Transarterial Chemoembolization for Hepatocellular Carcinoma. Journal of vascular and interventional radiology Müller, K., Datta, S., Gehrisch, S., Ahmad, M., Mohammed, M. A., Rosenberg, J., Hwang, G. L., Louie, J. D., Sze, D. Y., Kothary, N. 2017; 28 (2): 238-245

  Abstract

  To identify computational and qualitative features derived from dual-phase cone-beam CT that predict short-term response in patients undergoing transarterial chemoembolization for hepatocellular carcinoma (HCC).This retrospective study included 43 patients with 59 HCCs. Six features were extracted, including intensity of tumor enhancement on both phases and characteristics of the corona on the washout phase. Short-term response was evaluated by modified Response Evaluation Criteria in Solid Tumors on follow-up imaging, and extracted features were correlated to response using univariate and multivariate analyses.Univariate and multivariate analyses did not reveal a correlation between absolute and relative tumor enhancement characteristics on either phase with response (arterial P = .21; washout P = .40; ∆ P = .90). On multivariate analysis of qualitative characteristics, the presence of a diffuse corona was an independent predictor of incomplete response (P = .038) and decreased the odds ratio of objective response by half regardless of tumor size.Computational features extracted from contrast-enhanced dual-phase cone-beam CT are not prognostic of response to transarterial chemoembolization in patients with HCC. HCCs that demonstrate a diffuse, patchy corona have reduced odds of achieving complete response after transarterial chemoembolization and should be considered for additional treatment with an alternative modality.

  View details for DOI 10.1016/j.jvir.2016.09.019

  View details for PubMedID 27914917

• Yttrium-90 Radioembolization with Resin Microspheres without Routine Embolization of the Gastroduodenal Artery. Journal of vascular and interventional radiology Ward, T. J., Louie, J. D., Sze, D. Y. 2017; 28 (2): 246-253

  Abstract

  To evaluate safety of resin microsphere radioembolization (RE) without prophylactic embolization of the gastroduodenal artery (GDA).Between July 2013 and April 2015, all patients undergoing RE with resin microspheres for liver-dominant metastatic disease were treated without routine embolization of the GDA. Selective embolization of distal hepaticoenteric vessels was performed if identified by digital subtraction angiography, cone-beam computed tomography, or technetium-99m macroaggregated albumin scintigraphy. Resin microspheres were administered using 5% dextrose flush distal to the origin of the GDA in lobar or segmental fashion, with judicious use of an antireflux microcatheter in recognized high-risk situations. Gastrointestinal toxicity was evaluated by the performing physician for at least 3 months.RE with resin microspheres was performed in 62 patients undergoing 69 treatments. During planning angiography, embolization of 0 or 1 vessel (median, 1; range, 0-4) was performed in 86% of patients, most commonly the right gastric and supraduodenal arteries. Prophylactic embolization of the GDA was performed in only 2 patients (3%). In 6 treatments (9%), adjunctive embolization was required immediately before RE, and an antireflux microcatheter was used in 14% of treatments. Clinical follow-up was available in 60 of 62 patients (median, 134 d; range, 15-582 d). No signs or symptoms of gastric or duodenal ulceration were observed.RE using resin microspheres without embolization of the GDA can be performed safely.

  View details for DOI 10.1016/j.jvir.2016.09.002

  View details for PubMedID 27884683

• Noninvasive radiomics signature based on quantitative analysis of computed tomography images as a surrogate for microvascular invasion in hepatocellular carcinoma: a pilot study. Journal of medical imaging (Bellingham, Wash.) Bakr, S. n., Echegaray, S. n., Shah, R. n., Kamaya, A. n., Louie, J. n., Napel, S. n., Kothary, N. n., Gevaert, O. n. 2017; 4 (4): 041303

  Abstract

  We explore noninvasive biomarkers of microvascular invasion (mVI) in patients with hepatocellular carcinoma (HCC) using quantitative and semantic image features extracted from contrast-enhanced, triphasic computed tomography (CT). Under institutional review board approval, we selected 28 treatment-naive HCC patients who underwent surgical resection. Four radiologists independently selected and delineated tumor margins on three axial CT images and extracted computational features capturing tumor shape, image intensities, and texture. We also computed two types of "delta features," defined as the absolute difference and the ratio computed from all pairs of imaging phases for each feature. 717 arterial, portal-venous, delayed single-phase, and delta-phase features were robust against interreader variability ([Formula: see text]). An enhanced cross-validation analysis showed that combining robust single-phase and delta features in the arterial and venous phases identified mVI (AUC [Formula: see text]). Compared to a previously reported semantic feature signature (AUC 0.47 to 0.58), these features in our cohort showed only slight to moderate agreement (Cohen's kappa range: 0.03 to 0.59). Though preliminary, quantitative analysis of image features in arterial and venous phases may be potential surrogate biomarkers for mVI in HCC. Further study in a larger cohort is warranted.

  View details for PubMedID 28840174

• Superselective Chemoembolization of HCC: Comparison of Short-term Safety and Efficacy between Drug-eluting LC Beads, QuadraSpheres, and Conventional Ethiodized Oil Emulsion. Radiology Duan, F., Wang, E. Q., Lam, M. G., Abdelmaksoud, M. H., Louie, J. D., Hwang, G. L., Kothary, N., Kuo, W. T., Hofmann, L. V., Sze, D. Y. 2016; 278 (2): 612-621

  Abstract

  Purpose To study the comparative short-term safety and efficacy of transcatheter arterial chemoembolization (TACE) with drug-eluting LC Beads loaded with doxorubicin (DEBDOX), doxorubicin-eluting QuadraSpheres (hqTACE), and conventional TACE using ethiodized oil for superselective C-arm computed tomography (CT)-guided treatment of hepatocellular carcinoma (HCC) after the onset of drug shortages. Materials and Methods From March 2010 to March 2011, 166 patients with HCC were treated with 232 superselective TACE procedures using C-arm cone-beam CT at one institution. Patients underwent treatment depending on the availability of materials after the onset of drug shortages. Conventional TACE with doxorubicin, cisplatin, and Ethiodol was performed for 159 procedures, DEBDOX TACE was performed for 47, and hqTACE was performed for 26. Toxicity and objective response were compared at 3 months after treatment. Data were stratified for the high-risk population (Child-Pugh class B, performance status 1, bilobar disease, and/or post-resection recurrence) and initial versus repeat treatment. Kruskal-Wallis H test, Mann-Whitney U test, and Fisher exact test were used to compare the groups, with Bonferroni correction where needed. Results Whole liver response rates trended higher for conventional TACE (conventional TACE, 65.4%; DEBDOX, 63.8%; hqTACE, 53.8%) (P = .085). Only minor trends for differences in toxicity were observed between the three groups. Low-risk patients had higher whole liver (P = .001) and treated lesion (P = .007) response rates when treated with conventional TACE, but no significant differences were seen for DEBDOX and hqTACE. Treatment-naive patients also had higher whole liver (P = .012) and treated lesion (P = .056) response rates. No advantages for drug-eluting microspheres were found. Conclusion Within statistical power limitations, overall toxicity and efficacy were equivalent in patients treated with LC Beads, QuadraSpheres, or ethiodized oil emulsions, including in high-risk patients, when performed superselectively with cone-beam C-arm CT guidance. (©) RSNA, 2015.

  View details for DOI 10.1148/radiol.2015141417

  View details for PubMedID 26334787

• Management of High Hepatopulmonary Shunting in Patients Undergoing Hepatic Radioembolization. Journal of vascular and interventional radiology Ward, T. J., Tamrazi, A., Lam, M. G., Louie, J. D., Kao, P. N., Shah, R. P., Kadoch, M. A., Sze, D. Y. 2015; 26 (12): 1751-1760

  Abstract

  To review the safety of hepatic radioembolization (RE) in patients with high (≥ 10%) hepatopulmonary shunt fraction (HPSF) using various prophylactic techniques.A review was conducted of 409 patients who underwent technetium 99m-labeled macroaggregated albumin scintigraphy before planned RE. Estimated pulmonary absorbed radiation doses based on scintigraphy and hepatic administered activity were calculated. Outcomes from dose reductions and adjunctive catheter-based prophylactic techniques used to reduce lung exposure were assessed.There were 80 patients with HPSF ≥ 10% who received RE treatment (41 resin microspheres for metastases, 39 glass microspheres for hepatocellular carcinoma). Resin microspheres were used in 17 patients according to consensus guideline-recommended dose reduction; 38 patients received no dose reduction because the expected lung dose was < 30 Gy. Prophylactic techniques were used in 25 patients (with expected lung dose ≤ 74 Gy), including hepatic vein balloon occlusion, variceal embolization, or bland arterial embolization before, during, or after RE delivery. Repeated scintigraphy after prophylactic techniques to reduce HPSF in seven patients demonstrated a median change of -40% (range, +32 to -69%). Delayed pneumonitis developed in two patients, possibly related to radiation recall after chemoembolization. Response was lower in patients treated with resin spheres with dose reduction, with an objective response rate of 13% and disease control rate of 47% compared with 56% and 94%, respectively, without dose reduction (P = .023, P = .006).Dose reduction recommendations for HPSF may compromise efficacy. Excessive shunting can be reduced by prophylactic catheter-based techniques, which may improve the safety of performing RE in patients with high HPSF.

  View details for DOI 10.1016/j.jvir.2015.08.027

  View details for PubMedID 26525118

• Core samples for radiomics features that are insensitive to tumor segmentation: method and pilot study using CT images of hepatocellular carcinoma. Journal of medical imaging (Bellingham, Wash.) Echegaray, S., Gevaert, O., Shah, R., Kamaya, A., Louie, J., Kothary, N., Napel, S. 2015; 2 (4): 041011-?

  Abstract

  The purpose of this study is to investigate the utility of obtaining "core samples" of regions in CT volume scans for extraction of radiomic features. We asked four readers to outline tumors in three representative slices from each phase of multiphasic liver CT images taken from 29 patients (1128 segmentations) with hepatocellular carcinoma. Core samples were obtained by automatically tracing the maximal circle inscribed in the outlines. Image features describing the intensity, texture, shape, and margin were used to describe the segmented lesion. We calculated the intraclass correlation between the features extracted from the readers' segmentations and their core samples to characterize robustness to segmentation between readers, and between human-based segmentation and core sampling. We conclude that despite the high interreader variability in manually delineating the tumor (average overlap of 43% across all readers), certain features such as intensity and texture features are robust to segmentation. More importantly, this same subset of features can be obtained from the core samples, providing as much information as detailed segmentation while being simpler and faster to obtain.

  View details for DOI 10.1117/1.JMI.2.4.041011

  View details for PubMedID 26587549

• Watershed Hepatocellular Carcinomas: The Risk of Incomplete Response following Transhepatic Arterial Chemoembolization. Journal of vascular and interventional radiology Kothary, N., Takehana, C., Mueller, K., Sullivan, P., Tahvildari, A., Sidhar, V., Rosenberg, J., Louie, J. D., Sze, D. Y. 2015; 26 (8): 1122-1129

  Abstract

  Hepatocellular carcinomas (HCCs) bridging two or more Couinaud-Bismuth segments of the liver ("watershed tumors") can recruit multiple segmental arteries. The primary hypothesis of this study was that fewer watershed tumors show complete response (CR) after chemoembolization, with shorter time to local recurrence. Secondary analysis on the impact on transplantation eligibility in the presence of progressive disease was also performed.A total of 155 transplantation-eligible patients whose HCC met Milan criteria (watershed, n = 83; nonwatershed, n = 72) and was treated with chemoembolization were included. Cone-beam computed tomography (CT) was used for guidance and for confirmation of circumferential uptake. Local response to chemoembolization per modified Response Evaluation Criteria In Solid Tumors and local disease-free survival (DFS) for the index tumor were calculated. Differences were assessed by univariate and multivariate analyses.CR after a single of chemoembolization was observed in 55.4% of watershed tumors and in 72.2% of nonwatershed tumors (P = .045). Estimated DFS intervals were 151 days (95% confidence interval [CI], 93-245 d) and 336 days (95% CI, 231-747 d; P = .040) in the watershed and nonwatershed groups, respectively. Worse DFS was observed with a Model for End-Stage Liver Disease score > 20 (P = .0001), higher Child-Pugh-Turcotte score (P = .049), and watershed location (P = .040). Waiting list drop-off rates were statistically similar between groups.Hepatocellular carcinomas located in the watershed region of the liver have a poorer response to chemoembolization than those located elsewhere. These tumors are associated with worse DFS and require additional treatments to maintain transplantation eligibility per Milan criteria. Cone-beam CT can identify crossover supply and confirm complete geographic drug uptake, possibly reducing (but not eliminating) the risk of incomplete response.

  View details for DOI 10.1016/j.jvir.2015.04.030

  View details for PubMedID 26091800

• Fusion dual-tracer SPECT-based hepatic dosimetry predicts outcome after radioembolization for a wide range of tumour cell types EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING Lam, M. G., Banerjee, A., Goris, M. L., Iagaru, A. H., Mittra, E. S., Louie, J. D., Sze, D. Y. 2015; 42 (8): 1192-1201

  Abstract

  Fusion dual-tracer SPECT imaging enables physiological rather than morphological voxel-based partitioning and dosimetry for (90)Y hepatic radioembolization (RE). We evaluated its prognostic value in a large heterogeneous cohort of patients with extensive hepatic malignancy.A total of 122 patients with primary or secondary liver malignancy (18 different cell types) underwent SPECT imaging after intraarterial injection of (99m)Tc macroaggregated albumin (TcMAA) as a simulation of subsequent (90)Y microsphere distribution, followed by administration of an excess of intravenous (99m)Tc-labelled sulphur colloid (TcSC) as a biomarker for functional liver, and a second SPECT scan. TcMAA distribution was used to estimate (90)Y radiation absorbed dose in tumour (D T) and in functional liver. Laboratory and clinical follow-up were recorded for 12 weeks after RE, and radiographic responses according to (m)RECIST were evaluated at 3 and 6 months. Dose-response relationships were determined for efficacy and toxicity.Patients were treated with a median of 1.73 GBq activity of resin microspheres (98 patients) or glass microspheres (24 patients), in a whole-liver approach (97 patients) or a lobar approach (25 patients). The objective response rate was 41 % at 3 months and 48 % at 6 months. Response was correlated with D T (P < 0.01). Median overall survival was 10.1 months (95 % confidence interval 7.4 - 12.8 months). Responders lived for 36.0 months compared to 8.7 months for nonresponders (P < 0.01). Stratified for tumour cell type, D T was independently associated with survival (P < 0.01). Absorbed dose in functional liver was correlated with toxicity grade change (P < 0.05) and RE-induced liver disease (P < 0.05).Fusion dual-tracer SPECT imaging offers a physiology-based functional imaging tool to predict efficacy and toxicity of RE. This technique can be refined to define dosing thresholds for specific tumour types and treatments, but appears generally predictive even in a heterogeneous cohort.

  View details for DOI 10.1007/s00259-015-3048-z

  View details for PubMedID 25916740

• Emergent Salvage Direct Intrahepatic Portocaval Shunt Procedure for Acute Variceal Hemorrhage JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Ward, T. J., Techasith, T., Louie, J. D., Hwang, G. L., Hofmann, L. V., Sze, D. Y. 2015; 26 (6): 829-834

  Abstract

  To review the safety and effectiveness of direct intrahepatic portocaval shunt (DIPS) creation with variceal embolization for acute variceal hemorrhage after a failed transjugular intrahepatic portosystemic shunt (TIPS) creation attempt or in patients with prohibitive anatomy.Transjugular intrahepatic portosystemic shunt and DIPS procedures performed for variceal hemorrhage between January 2008 and July 2014 were reviewed. The default procedure was TIPS creation, with DIPS creation reserved for patients with unfavorable anatomy or who had technically unsuccessful TIPS creation. Thirteen patients underwent DIPS creation (mean age, 60 y ± 12; Child-Pugh class A/B/C, 8%/62%/30%; Model for End-stage Liver Disease score, 15 ± 5; range, 8-26) and 117 underwent TIPS creation. Four patients underwent a TIPS attempt and were converted to DIPS creation upon technical failure; 9 were treated primarily with DIPS creation because of preprocedural imaging revealing unfavorable anatomy (intrahepatic portal thrombosis, n = 2; venous distortion from prior hepatic resections, n = 2; severely angulated hepatic veins, n = 5).Direct intrahepatic portocaval shunt creation with variceal embolization (six gastric or esophageal; seven stomal, duodenal, or rectal) was successful in all patients; 11 also had concomitant variceal sclerotherapy. Mean DIPS procedure time was less than 2 hours. There was 1 major procedural complication. During a mean follow-up of 13.0 months ± 15.5, 1 patient developed DIPS thrombosis and recurrent hemorrhage; 1 patient underwent successful transplantation. Two deaths were observed within 30 days, neither associated with recurrent hemorrhage.Direct intrahepatic portocaval shunt creation appears to be a safe, expedient, and effective treatment for patients with acute variceal hemorrhage who are poor anatomic candidates for TIPS creation or who have undergone unsuccessful TIPS creation attempts.

  View details for DOI 10.1016/j.jvir.2015.03.004

  View details for PubMedID 25881512

• Optimal imaging surveillance schedules after liver-directed therapy for hepatocellular carcinoma. Journal of vascular and interventional radiology Boas, F. E., Do, B., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hovsepian, D. M., Kantrowitz, M., Sze, D. Y. 2015; 26 (1): 69-73

  Abstract

  To optimize surveillance schedules for the detection of recurrent hepatocellular carcinoma (HCC) after liver-directed therapy.New methods have emerged that allow quantitative analysis and optimization of surveillance schedules for diseases with substantial rates of recurrence such as HCC. These methods were applied to 1,766 consecutive chemoembolization, radioembolization, and radiofrequency ablation procedures performed on 910 patients between 2006 and 2011. Computed tomography or magnetic resonance imaging performed just before repeat therapy was set as the time of "recurrence," which included residual and locally recurrent tumor as well as new liver tumors. Time-to-recurrence distribution was estimated by Kaplan-Meier method. Average diagnostic delay (time between recurrence and detection) was calculated for each proposed surveillance schedule using the time-to-recurrence distribution. An optimized surveillance schedule could then be derived to minimize the average diagnostic delay.Recurrence is 6.5 times more likely in the first year after treatment than in the second. Therefore, screening should be much more frequent in the first year. For eight time points in the first 2 years of follow-up, the optimal schedule is 2, 4, 6, 8, 11, 14, 18, and 24 months. This schedule reduces diagnostic delay compared with published schedules and is cost-effective.The calculated optimal surveillance schedules include shorter-interval follow-up when there is a higher probability of recurrence and longer-interval follow-up when there is a lower probability. Cost can be optimized for a specified acceptable diagnostic delay or diagnostic delay can be optimized within a specified acceptable cost.

  View details for DOI 10.1016/j.jvir.2014.09.013

  View details for PubMedID 25446423

• Getting the dead out: modern treatment strategies for necrotizing pancreatitis. Digestive diseases and sciences Dua, M. M., Worhunsky, D. J., Amin, S., Louie, J. D., Park, W. G., Triadafilopoulos, G., Visser, B. C. 2014; 59 (9): 2069-2075

  View details for DOI 10.1007/s10620-014-3153-z

  View details for PubMedID 24748229

• Splenomegaly-associated thrombocytopenia after hepatic yttrium-90 radioembolization. Cardiovascular and interventional radiology Lam, M. G., Banerjee, A., Louie, J. D., Sze, D. Y. 2014; 37 (4): 1009-1017

  Abstract

  Thrombocytopenia is often observed after yttrium-90 radioembolization (RE). Possible mechanisms include radiation toxicity to the bone marrow, consumption in the liver due to local radiation effects, and sequestration in the spleen. We sought to identify the causative factors.Patients with complete baseline and 3-month post-RE imaging and laboratory data were included in this retrospective analysis. Univariate and multivariate regression analyses were performed on clinical, procedural, and imaging data.A total of 116 patients were identified (65 male, 51 female; median age 64 years). Forty-six patients were treated for primary and 70 for metastatic liver malignancy. Of these, 86 were treated with resin and 30 with glass microspheres; median activity was 1.85 GBq. Eighty-three patients underwent whole-liver treatment. Maximum individual change in platelet count was -20.2 % leading to new or increased grade of thrombocytopenia in 48 patients (41.4 %) by National Cancer Institute Common Toxicity Criteria for Adverse Events version 4.02 criteria. Independent risk factors for decreased platelet count included change in spleen volume (median change +17.5 %; p = 0.001) and whole-liver (rather than lobar or segmental) treatment (p = 0.025). Administered activity and absorbed dose were not associated with change in platelet count. The change in spleen volume itself was associated with previous epidermal growth factor receptor-inhibitor treatment (p = 0.002), whole-liver absorbed dose (p = 0.027), and multiple-line chemotherapy (0.012) for whole-liver treatments only.Post-RE treatment increase of spleen volume is correlated with decreased peripheral platelet count suggesting a mechanism of increased portal hypertension and hypersplenism being responsible.

  View details for DOI 10.1007/s00270-013-0742-8

  View details for PubMedID 24091754

• Limitations of body surface area-based activity calculation for radioembolization of hepatic metastases in colorectal cancer. Journal of vascular and interventional radiology Lam, M. G., Louie, J. D., Abdelmaksoud, M. H., Fisher, G. A., Cho-Phan, C. D., Sze, D. Y. 2014; 25 (7): 1085-1093

  Abstract

  To calculate absorbed radiation doses in patients treated with resin microspheres prescribed by the body surface area (BSA) method and to analyze dose-response and toxicity relationships.A retrospective review was performed of 45 patients with colorectal carcinoma metastases who received single-session whole-liver resin microsphere radioembolization. Prescribed treatment activity was calculated using the BSA method. Liver volumes and whole-liver absorbed doses (D(WL)) were calculated. D(WL) was correlated with toxicity and radiographic and biochemical response.The standard BSA-based administered activity (range, 0.85-2.58 GBq) did not correlate with D(WL) (mean, 50.4 Gy; range, 29.8-74.7 Gy; r = -0.037; P = .809) because liver weight was highly variable (mean, 1.89 kg; range, 0.94-3.42 kg) and strongly correlated with D(WL) (r = -0.724; P < .001) but was not accounted for in the BSA method. Patients with larger livers were relatively underdosed, and patients with smaller livers were relatively overdosed. Patients who received D(WL) > 50 Gy experienced more toxicity and adverse events (> grade 2 liver toxicity, 46% vs 17%; P < .05) but also responded better to the treatment than patients who received D(WL)< 50 Gy (disease control, 88% vs 24%; P < .01).Using the standard BSA formula, the administered activity did not correlate with D(WL). Based on this short-term follow-up after salvage therapy in patients with late stage metastatic colorectal carcinoma, dose-response and dose-toxicity relationships support using a protocol based on liver volume rather than BSA to prescribe the administered activity.

  View details for DOI 10.1016/j.jvir.2013.11.018

  View details for PubMedID 24457263

• Limitations of Body Surface Area-Based Activity Calculation for Radioembolization of Hepatic Metastases in Colorectal Cancer JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Lam, M. G., Louie, J. D., Abdelmaksoud, M. H., Fisher, G. A., Cho-Phan, C. D., Sze, D. Y. 2014; 25 (7): 1085-1093

  Abstract

  To calculate absorbed radiation doses in patients treated with resin microspheres prescribed by the body surface area (BSA) method and to analyze dose-response and toxicity relationships.A retrospective review was performed of 45 patients with colorectal carcinoma metastases who received single-session whole-liver resin microsphere radioembolization. Prescribed treatment activity was calculated using the BSA method. Liver volumes and whole-liver absorbed doses (D(WL)) were calculated. D(WL) was correlated with toxicity and radiographic and biochemical response.The standard BSA-based administered activity (range, 0.85-2.58 GBq) did not correlate with D(WL) (mean, 50.4 Gy; range, 29.8-74.7 Gy; r = -0.037; P = .809) because liver weight was highly variable (mean, 1.89 kg; range, 0.94-3.42 kg) and strongly correlated with D(WL) (r = -0.724; P < .001) but was not accounted for in the BSA method. Patients with larger livers were relatively underdosed, and patients with smaller livers were relatively overdosed. Patients who received D(WL) > 50 Gy experienced more toxicity and adverse events (> grade 2 liver toxicity, 46% vs 17%; P < .05) but also responded better to the treatment than patients who received D(WL)< 50 Gy (disease control, 88% vs 24%; P < .01).Using the standard BSA formula, the administered activity did not correlate with D(WL). Based on this short-term follow-up after salvage therapy in patients with late stage metastatic colorectal carcinoma, dose-response and dose-toxicity relationships support using a protocol based on liver volume rather than BSA to prescribe the administered activity.

  View details for DOI 10.1016/j.jvir.2013.11.018

  View details for Web of Science ID 000338174200016

• Root cause analysis of gastroduodenal ulceration after yttrium-90 radioembolization. Cardiovascular and interventional radiology Lam, M. G., Banerjee, S., Louie, J. D., Abdelmaksoud, M. H., Iagaru, A. H., Ennen, R. E., Sze, D. Y. 2013; 36 (6): 1536-1547

  Abstract

  INTRODUCTION: A root cause analysis was performed on the occurrence of gastroduodenal ulceration after hepatic radioembolization (RE). We aimed to identify the risk factors in the treated population and to determine the specific mechanism of nontarget RE in individual cases. METHODS: The records of 247 consecutive patients treated with yttrium-90 RE for primary (n = 90) or metastatic (n = 157) liver cancer using either resin (n = 181) or glass (n = 66) microspheres were reviewed. All patients who developed a biopsy-proven microsphere-induced gastroduodenal ulcer were identified. Univariate and multivariate analyses were performed on baseline parameters and procedural data to determine possible risk factors in the total population. Individual cases were analyzed to ascertain the specific cause, including identification of the culprit vessel(s) leading to extrahepatic deposition of the microspheres. RESULTS: Eight patients (3.2 %) developed a gastroduodenal ulcer. Stasis during injection was the strongest independent risk factor (p = 0.004), followed by distal origin of the gastroduodenal artery (p = 0.004), young age (p = 0.040), and proximal injection of the microspheres (p = 0.043). Prolonged administrations, pain during administration, whole liver treatment, and use of resin microspheres also showed interrelated trends in multivariate analysis. Retrospective review of intraprocedural and postprocedural imaging showed a probable or possible culprit vessel, each a tiny complex collateral vessel, in seven patients. CONCLUSION: Proximal administrations and those resulting in stasis of flow presented increased risk for gastroduodenal ulceration. Patients who had undergone bevacizumab therapy were at high risk for developing stasis.

  View details for DOI 10.1007/s00270-013-0579-1

  View details for PubMedID 23435742

• Prognostic utility of 90Y radioembolization dosimetry based on fusion 99mTc-macroaggregated albumin-99mTc-sulfur colloid SPECT. Journal of nuclear medicine : official publication, Society of Nuclear Medicine Lam, M. G., Goris, M. L., Iagaru, A. H., Mittra, E. S., Louie, J. D., Sze, D. Y. 2013; 54 (12): 2055-2061

  Abstract

  Planning hepatic (90)Y radioembolization activity requires balancing toxicity with efficacy. We developed a dual-tracer SPECT fusion imaging protocol that merges data on radioactivity distribution with physiologic liver mapping.Twenty-five patients with colorectal carcinoma and bilobar liver metastases received whole-liver radioembolization with resin microspheres prescribed as per convention (mean administered activity, 1.69 GBq). As part of standard treatment planning, all patients underwent SPECT imaging after intraarterial injection of 37 MBq of (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) to simulate subsequent (90)Y distribution. Immediately afterward, patients received 185 MBq of labeled sulfur colloid ((99m)Tc-SC) intravenously as a biomarker for normal hepatic reticuloendothelial function and SPECT was repeated. The SPECT images were coregistered and fused. A region-based method was used to predict the (90)Y radiation absorbed dose to functional liver tissue (DFL) by calculation of (99m)Tc-MAA activity in regions with (99m)Tc-SC uptake. Similarly, the absorbed dose to tumor (DT) was predicted by calculation of (99m)Tc-MAA activity in voxels without (99m)Tc-SC uptake. Laboratory data and radiographic response were measured for 3 mo, and the survival of patients was recorded. SPECT-based DT and DFL were correlated with parameters of toxicity and efficacy.Toxicity, as measured by increase in serum liver enzymes, correlated significantly with SPECT-based calculation of DFL at all time points (P < 0.05) (mean DFL, 27.9 Gy). Broad biochemical toxicity (>50% increase in all liver enzymes) occurred at a DFL of 24.5 Gy and above. In addition, in uni- and multivariate analysis, SPECT-based calculation of DT (mean DT, 44.2 Gy) correlated with radiographic response (P < 0.001), decrease in serum carcinoembryonic antigen (P < 0.05), and overall survival (P < 0.01). The cutoff value of DT for prediction of 1-y survival was 55 Gy (area under the receiver-operating-characteristic curve = 0.86; P < 0.01). Patients who received a DT of more than 55 Gy had a median survival of 32.8 mo, compared with 7.2 mo in patients who received less (P < 0.05).Dual-tracer (99m)Tc-MAA-(99m)Tc-SC fusion SPECT offers a physiology-based imaging tool with significant prognostic power that may lead to improved personalized activity planning.

  View details for DOI 10.2967/jnumed.113.123257

  View details for PubMedID 24144563

• Prognostic Utility of Y-90 Radioembolization Dosimetry Based on Fusion Tc-99m-Macroaggregated Albumin-Tc-99m-Sulfur Colloid SPECT JOURNAL OF NUCLEAR MEDICINE Lam, M. G., Goris, M. L., Iagaru, A. H., Mittra, E. S., Louie, J. D., Sze, D. Y. 2013; 54 (12): 2055-2061

  Abstract

  Planning hepatic (90)Y radioembolization activity requires balancing toxicity with efficacy. We developed a dual-tracer SPECT fusion imaging protocol that merges data on radioactivity distribution with physiologic liver mapping.Twenty-five patients with colorectal carcinoma and bilobar liver metastases received whole-liver radioembolization with resin microspheres prescribed as per convention (mean administered activity, 1.69 GBq). As part of standard treatment planning, all patients underwent SPECT imaging after intraarterial injection of 37 MBq of (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) to simulate subsequent (90)Y distribution. Immediately afterward, patients received 185 MBq of labeled sulfur colloid ((99m)Tc-SC) intravenously as a biomarker for normal hepatic reticuloendothelial function and SPECT was repeated. The SPECT images were coregistered and fused. A region-based method was used to predict the (90)Y radiation absorbed dose to functional liver tissue (DFL) by calculation of (99m)Tc-MAA activity in regions with (99m)Tc-SC uptake. Similarly, the absorbed dose to tumor (DT) was predicted by calculation of (99m)Tc-MAA activity in voxels without (99m)Tc-SC uptake. Laboratory data and radiographic response were measured for 3 mo, and the survival of patients was recorded. SPECT-based DT and DFL were correlated with parameters of toxicity and efficacy.Toxicity, as measured by increase in serum liver enzymes, correlated significantly with SPECT-based calculation of DFL at all time points (P < 0.05) (mean DFL, 27.9 Gy). Broad biochemical toxicity (>50% increase in all liver enzymes) occurred at a DFL of 24.5 Gy and above. In addition, in uni- and multivariate analysis, SPECT-based calculation of DT (mean DT, 44.2 Gy) correlated with radiographic response (P < 0.001), decrease in serum carcinoembryonic antigen (P < 0.05), and overall survival (P < 0.01). The cutoff value of DT for prediction of 1-y survival was 55 Gy (area under the receiver-operating-characteristic curve = 0.86; P < 0.01). Patients who received a DT of more than 55 Gy had a median survival of 32.8 mo, compared with 7.2 mo in patients who received less (P < 0.05).Dual-tracer (99m)Tc-MAA-(99m)Tc-SC fusion SPECT offers a physiology-based imaging tool with significant prognostic power that may lead to improved personalized activity planning.

  View details for DOI 10.2967/jnumed.113.123257

  View details for Web of Science ID 000328013000006

• Safety of (90)y radioembolization in patients who have undergone previous external beam radiation therapy. International journal of radiation oncology, biology, physics Lam, M. G., Abdelmaksoud, M. H., Chang, D. T., Eclov, N. C., Chung, M. P., Koong, A. C., Louie, J. D., Sze, D. Y. 2013; 87 (2): 323-329

  Abstract

  Previous external beam radiation therapy (EBRT) is theoretically contraindicated for yttrium-90 ((90)Y) radioembolization (RE) because the liver has a lifetime tolerance to radiation before becoming vulnerable to radiation-induced liver disease. We analyzed the safety of RE as salvage treatment in patients who had previously undergone EBRT.Between June 2004 and December 2010, a total of 31 patients who had previously undergone EBRT were treated with RE. Three-dimensional treatment planning with dose-volume histogram (DVH) analysis of the liver was used to calculate the EBRT liver dose. Liver-related toxicities including RE-induced liver disease (REILD) were reviewed and classified according to Common Terminology Criteria for Adverse Events version 4.02.The mean EBRT and RE liver doses were 4.40 Gy (range, 0-23.13 Gy) and 57.9 Gy (range, 27.0-125.9 Gy), respectively. Patients who experienced hepatotoxicity (≥grade2; n=12) had higher EBRT mean liver doses (7.96 ± 8.55 Gy vs 1.62 ± 3.39 Gy; P=.037), the only independent predictor in multivariate analysis. DVH analysis showed that the fraction of liver exposed to ≥30 Gy (V30) was the strongest predictor of hepatotoxicity (10.14% ± 12.75% vs 0.84% ± 3.24%; P=.006). All patients with V30 >13% experienced hepatotoxicity. Fatal REILD (n=2) occurred at the 2 highest EBRT mean liver doses (20.9 Gy and 23.1 Gy) but also at the highest cumulative liver doses (91.8 Gy and 149 Gy).Prior exposure of the liver to EBRT may lead to increased liver toxicity after RE treatment, depending on fractional liver exposure and dose level. The V30 was the strongest predictor of toxicity. RE appears to be safe for the treatment of hepatic malignancies only in patients who have had limited hepatic exposure to prior EBRT.

  View details for DOI 10.1016/j.ijrobp.2013.05.041

  View details for PubMedID 23849697

• Safety of repeated yttrium-90 radioembolization. Cardiovascular and interventional radiology Lam, M. G., Louie, J. D., Iagaru, A. H., Goris, M. L., Sze, D. Y. 2013; 36 (5): 1320-1328

  Abstract

  PURPOSE: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver's cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. METHODS: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51-71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. RESULTS: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). CONCLUSION: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction.

  View details for DOI 10.1007/s00270-013-0547-9

  View details for PubMedID 23354961

• Carbon Dioxide Contrast Enhancement for C-Arm CT Utility for Treatment Planning during Hepatic Embolization Procedures. Journal of vascular and interventional radiology Wong, A. A., Charalel, R. A., Louie, J. D., Sze, D. Y. 2013; 24 (7): 975-980

  Abstract

  A pilot study was performed to evaluate the use of carbon dioxide (CO2) as a contrast medium for C-arm computed tomography (CT). C-arm CT using CO2 was performed during embolization procedures in12 patients with hepatic malignancies and severe iodine allergy or high risk for nephrotoxicity. C-arm CT using gadolinium or iodinated contrast medium was performed for comparison. Of segmental arteries identified by conventional contrast enhancement, 96% were also seen with CO2 enhancement, but subsegmental arteries were not reliably depicted. CO2 enhancement identified 60% of tumors. Small, hypovascular, and infiltrative tumors were difficult to detect. CO2 is a promising alternative intraarterial contrast agent for C-arm CT.

  View details for DOI 10.1016/j.jvir.2013.03.029

  View details for PubMedID 23796085

• N-butyl Cyanoacrylate Glue Embolization of Arterial Networks to Facilitate Hepatic Arterial Skeletonization before Radioembolization. Cardiovascular and interventional radiology Samuelson, S. D., Louie, J. D., Sze, D. Y. 2013; 36 (3): 690-698

  Abstract

  Avoidance of nontarget microsphere deposition via hepatoenteric anastomoses is essential to the safety of yttrium-90 radioembolization (RE). The hepatic hilar arterial network may remain partially patent after coil embolization of major arteries, resulting in persistent risk. We retrospectively reviewed cases where n-butyl cyanoacrylate (n-BCA) glue embolization was used to facilitate endovascular hepatic arterial skeletonization before RE.A total of 543 RE procedures performed between June 2004 and March 2012 were reviewed, and 10 were identified where n-BCA was used to embolize hepatoenteric anastomoses. Arterial anatomy, prior coil embolization, and technical details were recorded. Outcomes were reviewed to identify subsequent complications of n-BCA embolization or nontarget RE.The rate of complete technical success was 80 % and partial success 20 %, with one nontarget embolization complication resulting in a minor change in treatment plan. No evidence of gastrointestinal or biliary ischemia or infarction was identified, and no microsphere-related gastroduodenal ulcerations or other evidence of nontarget RE were seen. Median volume of n-BCA used was <0.1 ml.n-BCA glue embolization is useful to eliminate hepatoenteric networks that may result in nontarget RE, especially in those that persist after coil embolization of major vessels such as the gastroduodenal and right gastric arteries.

  View details for DOI 10.1007/s00270-012-0490-1

  View details for PubMedID 23070102

• Prophylactic Topically Applied Ice to Prevent Cutaneous Complications of Nontarget Chemoembolization and Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Wang, D. S., Louie, J. D., Kothary, N., Shah, R. P., Sze, D. Y. 2013; 24 (4): 596-600

  Abstract

  Cutaneous complications can result from nontarget deposition during transcatheter arterial chemoembolization or radioembolization. Liver tumors may receive blood supply from parasitized extrahepatic arteries (EHAs) that also perfuse skin or from hepatic arteries located near the origin of the falciform artery (FA), which perfuses the anterior abdominal wall. To vasoconstrict cutaneous vasculature and prevent nontarget deposition, ice packs were topically applied to at-risk skin in nine chemoembolization treatments performed via 14 parasitized EHAs, seven chemoembolization treatments near the FA origin, and five radioembolization treatments in cases in which the FA could not be prophylactically coil-embolized. No postprocedural cutaneous complications were encountered.

  View details for DOI 10.1016/j.jvir.2012.12.020

  View details for PubMedID 23522163

• Intra-arterial therapies for metastatic colorectal cancer. Seminars in interventional radiology Wang, D. S., Louie, J. D., Sze, D. Y. 2013; 30 (1): 12-20

  Abstract

  Intra-arterial therapies for unresectable hepatic metastases from colorectal cancer include radioembolization (RE) with yttrium-90 microspheres, transarterial chemoembolization (TACE), hepatic arterial infusion, and percutaneous hepatic perfusion using an organ isolation system. In this article, we discuss our approach toward treatment selection, followed by details of how RE and TACE are performed at our institution.

  View details for DOI 10.1055/s-0033-1333649

  View details for PubMedID 24436513

• Intra-Arterial Therapies for Metastatic Colorectal Cancer SEMINARS IN INTERVENTIONAL RADIOLOGY Wang, D. S., Louie, J. D., Sze, D. Y. 2013; 30 (1): 12-20

  Abstract

  Intra-arterial therapies for unresectable hepatic metastases from colorectal cancer include radioembolization (RE) with yttrium-90 microspheres, transarterial chemoembolization (TACE), hepatic arterial infusion, and percutaneous hepatic perfusion using an organ isolation system. In this article, we discuss our approach toward treatment selection, followed by details of how RE and TACE are performed at our institution.

  View details for DOI 10.1055/s-0033-1333649

  View details for Web of Science ID 000209513000003

  View details for PubMedCentralID PMC3700785

• Preoperative embolization of replaced right hepatic artery prior to pancreaticoduodenectomy JOURNAL OF SURGICAL ONCOLOGY Cloyd, J. M., Chandra, V., Louie, J. D., Rao, S., Visser, B. C. 2012; 106 (4): 509-512

  Abstract

  Aberrancy of the hepatic arterial anatomy is common. Because of its course directly adjacent to the head of the pancreas, a replaced right hepatic artery (RHA) is vulnerable to invasion by peri-pancreatic malignancies. Division of the RHA at the time of pancreaticoduodenectomy, however, may result in hepatic infarction and/or bilioenteric anastomotic complications. We report two cases of patients undergoing preoperative embolization of tumor encased replaced RHAs to allow for sufficient collateralization prior to pancreaticoduodenectomy.

  View details for DOI 10.1002/jso.23082

  View details for PubMedID 22374866

• Complex Retrieval of Embedded IVC Filters: Alternative Techniques and Histologic Tissue Analysis CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Cupp, J. S., Louie, J. D., Kothary, N., Hofmann, L. V., Sze, D. Y., Hovsepian, D. M. 2012; 35 (3): 588-597

  Abstract

  We evaluated the safety and effectiveness of alternative endovascular methods to retrieve embedded optional and permanent filters in order to manage or reduce risk of long-term complications from implantation. Histologic tissue analysis was performed to elucidate the pathologic effects of chronic filter implantation.We studied the safety and effectiveness of alternative endovascular methods for removing embedded inferior vena cava (IVC) filters in 10 consecutive patients over 12 months. Indications for retrieval were symptomatic chronic IVC occlusion, caval and aortic perforation, and/or acute PE (pulmonary embolism) from filter-related thrombus. Retrieval was also performed to reduce risk of complications from long-term filter implantation and to eliminate the need for lifelong anticoagulation. All retrieved specimens were sent for histologic analysis.Retrieval was successful in all 10 patients. Filter types and implantation times were as follows: one Venatech (1,495 days), one Simon-Nitinol (1,485 days), one Optease (300 days), one G2 (416 days), five Günther-Tulip (GTF; mean 606 days, range 154-1,010 days), and one Celect (124 days). There were no procedural complications or adverse events at a mean follow-up of 304 days after removal (range 196-529 days). Histology revealed scant native intima surrounded by a predominance of neointimal hyperplasia and dense fibrosis in all specimens. Histologic evidence of photothermal tissue ablation was confirmed in three laser-treated specimens.Complex retrieval methods can now be used in select patients to safely remove embedded optional and permanent IVC filters previously considered irretrievable. Neointimal hyperplasia and dense fibrosis are the major components that must be separated to achieve successful retrieval of chronic filter implants.

  View details for DOI 10.1007/s00270-011-0175-1

  View details for PubMedID 21562933

• Applying a Structured Innovation Process to Interventional Radiology: A Single-Center Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sista, A. K., Hwang, G. L., Hovsepian, D. M., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Yamada, K., Hong, R., Dhanani, R., Brinton, T. J., Krummel, T. M., Makower, J., Yock, P. G., Hofmann, L. V. 2012; 23 (4): 488-494

  Abstract

  To determine the feasibility and efficacy of applying an established innovation process to an active academic interventional radiology (IR) practice.The Stanford Biodesign Medical Technology Innovation Process was used as the innovation template. Over a 4-month period, seven IR faculty and four IR fellow physicians recorded observations. These observations were converted into need statements. One particular need relating to gastrostomy tubes was diligently screened and was the subject of a single formal brainstorming session.Investigators collected 82 observations, 34 by faculty and 48 by fellows. The categories that generated the most observations were enteral feeding (n = 9, 11%), biopsy (n = 8, 10%), chest tubes (n = 6, 7%), chemoembolization and radioembolization (n = 6, 7%), and biliary interventions (n = 5, 6%). The output from the screening on the gastrostomy tube need was a specification sheet that served as a guidance document for the subsequent brainstorming session. The brainstorming session produced 10 concepts under three separate categories.This formalized innovation process generated numerous observations and ultimately 10 concepts to potentially to solve a significant clinical need, suggesting that a structured process can help guide an IR practice interested in medical innovation.

  View details for DOI 10.1016/j.jvir.2011.12.029

  View details for Web of Science ID 000302396300009

  View details for PubMedID 22464713

• Yttrium-90 Radioembolization of Renal Cell Carcinoma Metastatic to the Liver JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Hwang, G. L., Kothary, N., Minor, D. R., Sze, D. Y. 2012; 23 (3): 323-330

  Abstract

  To investigate the safety and efficacy of yttrium-90 ((90)Y) hepatic radioembolization treatment of patients with liver-dominant metastatic renal cell carcinoma (RCC) refractory to immunotherapy and targeted therapies.Between March 2006 and December 2010, six patients with metastatic RCC underwent eight radioembolization treatments with (90)Y-labeled resin microspheres for unresectable liver-dominant metastases. All six patients had previous hepatic tumor progression despite targeted therapies or immunotherapies. All had bilobar disease and required whole-liver treatment. Clinical and biochemical toxicities were recorded, and tumor response was assessed every 2-3 months after treatment by cross-sectional imaging.The median dose delivered was 1.89 Gbq (range 0.41-2.03 Gbq). Grade 1 and 2 toxicities were noted in all patients, primarily fatigue. Follow-up imaging was available for five patients. In follow-up periods from 2-64 months (mean 25 months), three patients showed complete responses, and 1 patient showed a partial response by standard imaging criteria, and these patients are alive at 64 months, 55 months, 17 months, and 7 months after treatment. Two patients with rapid progression of disease died within 2 months of treatment, although hepatic malignancy or failure was not the cause of death in either patient.(90)Y radioembolization is a promising option for liver-dominant metastatic RCC with potential for providing long-term survival in patients refractory to or intolerant of targeted therapies.

  View details for DOI 10.1016/j.jvir.2011.11.007

  View details for PubMedID 22277275

• Transarterial Chemoembolization for Hepatocellular Carcinomas in Watershed Segments: Utility of C-Arm Computed Tomography for Treatment Planning JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Hwang, G. L., Sze, D. Y., Hofmann, L. V., Kothary, N. 2012; 23 (2): 281-283

  View details for DOI 10.1016/j.jvir.2011.11.008

  View details for Web of Science ID 000299656600021

  View details for PubMedID 22264556

• Intravascular Ultrasound-Guided Mesocaval Shunt Creation in Patients with Portal or Mesenteric Venous Occlusion JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Hong, R., Dhanani, R. S., Louie, J. D., Sze, D. Y. 2012; 23 (1): 136-141

  Abstract

  Extrahepatic mesocaval shunts were successfully created in three patients with refractory variceal hemorrhage, complete portal vein or superior mesenteric vein occlusion, and contraindications to shunt surgery. The use of intravascular ultrasound guidance and covered stents allowed safe and effective transvenous shunt creation without the necessity of percutaneous transabdominal mesenteric venous puncture.

  View details for DOI 10.1016/j.jvir.2011.09.029

  View details for PubMedID 22221479

• Percutaneous Cholecystostomy for Acute Cholecystitis: Ten-Year Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Joseph, T., Unver, K., Hwang, G. L., Rosenberg, J., Sze, D. Y., Hashimi, S., Kothary, N., Louie, J. D., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M. 2012; 23 (1): 83-88

  Abstract

  To review the clinical course of patients with acute cholecystitis treated by percutaneous cholecystostomy, and to identify risk factors retrospectively that predict outcome.A total of 106 patients diagnosed with acute cholecystitis were treated by percutaneous cholecystostomy during a 10-year period. Seventy-one (67%) presented to the emergency department (ED) specifically for acute cholecystitis, and 35 (23%) were inpatients previously admitted for other conditions. Outcomes of the two groups were compared with respect to severity of illness, leukocytosis, bile culture, liver function tests, imaging features, time intervals from onset of symptoms to medical and percutaneous intervention, and whether surgical cholecystectomy was later performed.Overall, 72 patients (68%) showed an improvement clinically, whereas 34 (32%) showed no improvement or a clinically worsened condition after cholecystostomy. Patients who presented to the ED primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P < .0001). Gallstones were identified in 54% of patients who presented to the ED, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P < .0001). Bacterial bile cultures were analyzed in 95% of patients and showed positive results in 52%, with no overall effect on outcome. There was no correlation between the time of onset of symptoms until antibiotic therapy or cholecystostomy in either group. Long-term outcomes for both groups were better for those who later underwent cholecystectomy (P < .0001).Outcomes after percutaneous cholecystostomy for acute cholecystitis are better when the disease is primary and not precipitated by concurrent illness.

  View details for DOI 10.1016/j.jvir.2011.09.030

  View details for PubMedID 22133709

• Imaging Guidance with C-arm CT: Prospective Evaluation of Its Impact on Patient Radiation Exposure during Transhepatic Arterial Chemoembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Abdelmaksoud, M. H., Tognolini, A., Fahrig, R., Rosenberg, J., Hovsepian, D. M., Ganguly, A., Louie, J. D., Kuo, W. T., Hwang, G. L., Holzer, A., Sze, D. Y., Hofmann, L. V. 2011; 22 (11): 1535-1544

  Abstract

  To prospectively evaluate the impact of C-arm CT on radiation exposure to hepatocellular carcinoma (HCC) patients treated by chemoembolization.Patients with HCC (N = 87) underwent digital subtraction angiography (DSA; control group) or combined C-arm CT/DSA (test group) for chemoembolization. Dose-area product (DAP) and cumulative dose (CD) were measured for guidance and treatment verification. Contrast agent volume and C-arm CT utility were also measured.The marginal DAP increase in the test group was offset by a substantial (50%) decrease in CD from DSA. Use of C-arm CT allowed reduction of DAP and CD from DSA imaging (P = .007 and P = .017). Experienced operators were more efficient in substituting C-arm CT for DSA, resulting in a negligible increase (7.5%) in total DAP for guidance, compared with an increase of 34% for all operators (P = .03). For treatment verification, DAP from C-arm CT exceeded that from DSA, approaching that of conventional CT. The test group used less contrast medium (P = .001), and C-arm CT provided critical or supplemental information in 20% and 17% of patients, respectively.Routine use of C-arm CT can increase stochastic risk (DAP) but decrease deterministic risk (CD) from DSA. However, the increase in DAP is operator-dependent, thus, with experience, it can be reduced to under 10%. C-arm CT provides information not provided by DSA in 33% of patients, while decreasing the use of iodinated contrast medium. As with all radiation-emitting modalities, C-arm CT should be used judiciously.

  View details for DOI 10.1016/j.jvir.2011.07.008

  View details for PubMedID 21875814

• Embolization of Parasitized Extrahepatic Arteries to Reestablish Intrahepatic Arterial Supply to Tumors before Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1355-1362

  Abstract

  To perform embolization of parasitized extrahepatic arteries (EHAs) before radioembolization to reestablish intrahepatic arterial supply to large, peripheral tumors, and to evaluate the technical and clinical outcomes of this intervention.Among 201 patients retrospectively analyzed, embolization of 73 parasitized EHAs in 35 patients was performed. Most embolization procedures were performed during preparatory angiography using large particles and coils. Digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy were used to evaluate the immediate perfusion via intrahepatic collateral channels of target tumor areas previously supplied by parasitized EHAs. Follow-up imaging of differential regional tumor response was used to evaluate microsphere distribution and clinical outcome.After embolization, reestablishment of intrahepatic arterial supply was confirmed by both DSA and C-arm CT in 94% of territories and by scintigraphy in 96%. In 32% of patients, the differential response of treatment could not be evaluated because of uniform disease progression. However, symmetric regional tumor response in 94% of evaluable patients indicated successful delivery of microspheres to the territories previously supplied by parasitized EHAs.Reestablishment of intrahepatic arterial inflow to hepatic tumors by embolization of parasitized EHAs is safe and effective and results in successful delivery of yttrium-90 microspheres to tumors previously perfused by parasitized EHAs.

  View details for DOI 10.1016/j.jvir.2011.06.007

  View details for PubMedID 21961979

• Consolidation of Hepatic Arterial Inflow by Embolization of Variant Hepatic Arteries in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1364-1372

  Abstract

  Before yttrium-90 ((90)Y) radioembolization administration, the authors consolidated arterial inflow by embolizing variant hepatic arteries (HAs) to make microsphere delivery simpler and safer. The present study reviews the technical and clinical success of these consolidation procedures.Preparatory and treatment angiograms were retrospectively analyzed for 201 patients. Variant HAs were coil-embolized during preparatory angiography to simplify arterial anatomy. Collateral arterial perfusion of territories previously supplied by variant HAs was evaluated by digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) scintigraphy, and by follow-up evaluation of regional tumor response.A total of 47 variant HAs were embolized in 43 patients. After embolization of variant HAs, cross-perfusion into the embolized territory was depicted by DSA and by C-arm CT in 100% of patients and by (99m)Tc-MAA scintigraphy in 92.7%. Uniform progressive disease prevented evaluation in 33% of patients, but regional tumor response in patients who responded supported successful delivery of microspheres to the embolized territories in 95.5% of evaluable patients.Embolization of variant HAs for consolidation of hepatic supply in preparation for (90)Y radioembolization promotes treatment of affected territories via intrahepatic collateral channels.

  View details for DOI 10.1016/j.jvir.2011.06.014

  View details for PubMedID 21961981

• Photothermal Ablation with the Excimer Laser Sheath Technique for Embedded Inferior Vena Cava Filter Removal: Initial Results from a Prospective Study JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Odegaard, J. I., Louie, J. D., Sze, D. Y., Unver, K., Kothary, N., Rosenberg, J. K., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (6): 813-823

  Abstract

  To evaluate the safety and effectiveness of the excimer laser sheath technique for removing embedded inferior vena cava (IVC) filters.Over 12 months, 25 consecutive patients undergoing attempted IVC filter retrieval with a laser-assisted sheath technique were prospectively enrolled into an institutional review board-approved study registry. There were 10 men and 15 women (mean age 50 years, range 20-76 years); 18 (72%) of 25 patients were referred from an outside hospital. Indications for retrieval included symptomatic filter-related acute caval thrombosis (with or without acute pulmonary embolism), chronic IVC occlusion, and bowel penetration. Retrieval was also performed to remove risks from prolonged implantation and potentially to eliminate need for lifelong anticoagulation. After failure of standard methods, controlled photothermal ablation of filter-adherent tissue with a Spectranetics laser sheath and CVX-300 laser system was performed. All patients were evaluated with cavography, and specimens were sent for histologic analysis.Laser-assisted retrieval was successful in 24 (96%) of 25 patients as follows: 11 Günther Tulip (mean 375 days, range 127-882 days), 4 Celect (mean 387 days, range 332-440 days), 2 Option (mean 215 days, range 100-330 days), 4 OPTEASE (mean 387 days, range 71-749 days; 1 failed 188 days), 2 TRAPEASE (mean 871 days, range 187-1,555 days), and 2 Greenfield (mean 12.8 years, range 7.2-18.3 years). There was one (4%) major complication (acute thrombus, treated with thrombolysis), three (12%) minor complications (small extravasation, self-limited), and one adverse event (coagulopathic retroperitoneal hemorrhage) at follow-up (mean 126 days, range 13-302 days). Photothermal ablation of filter-adherent tissue was histologically confirmed in 23 (92%) of 25 patients.The laser-assisted sheath technique appears to be a safe and effective tool for retrieving embedded IVC filters, including permanent types, with implantation ranging from months to > 18 years.

  View details for DOI 10.1016/j.jvir.2011.01.459

  View details for PubMedID 21530309

• Intrahepatic Collateral Supply to the Previously Embolized Right Gastric Artery: A Potential Pitfall for Nontarget Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Meer, A. B., Louie, J. D., Abdelmaksoud, M. H., Kothary, N., Hovsepian, D. M., Hofmann, L. V., Kuo, W. T., Hwang, G. L., Sze, D. Y. 2011; 22 (4): 575-577

  View details for DOI 10.1016/j.jvir.2010.12.031

  View details for Web of Science ID 000289340100024

  View details for PubMedID 21463762

• Common Iliac Vein Stenosis and Risk of Symptomatic Pulmonary Embolism: An Inverse Correlation JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Chan, K. T., Popat, R. A., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (2): 133-141

  Abstract

  To test the hypothesis that a common iliac vein (CIV) stenosis may impair embolization of a large deep venous thrombosis (DVT) to the lungs, decreasing the incidence of a symptomatic pulmonary embolism (PE).Between January 2002 and August 2007, 75 patients diagnosed with unilateral DVT were included in a single-institution case-control study. Minimum CIV diameters were measured 1 cm below the inferior vena cava (IVC) bifurcation on computed tomography (CT) images. A significant stenosis in the CIV ipsilateral to the DVT was defined as having either a diameter 4 mm or less or a greater than 70% reduction in lumen diameter. A symptomatic PE was defined as having symptoms and imaging findings consistent with a PE. The odds of symptomatic PE versus CIV stenosis were assessed using logistic regression models. The associations between thrombus location, stenosis, and symptomatic PE were assessed using a stratified analysis.Of 75 subjects, 49 (65%) presented with symptomatic PE. There were 17 (23%) subjects with a venous lumen 4 mm or less and 12 (16%) subjects with a greater than 70% stenosis. CIV stenosis of 4 mm or less resulted in a decreased odds of a symptomatic PE compared with a lumen greater than 4 mm (odds ratio [OR] 0.17, P = .011), whereas a greater than 70% stenosis increased the odds of DVT involving the CIV (OR 7.1, P = .047).Among patients with unilateral DVT, those with an ipsilateral CIV lumen of 4 mm or less have an 83% lower risk of developing symptomatic PE compared with patients with a CIV lumen greater than 4 mm.

  View details for DOI 10.1016/j.jvir.2010.10.009

  View details for PubMedID 21276911

• C-arm Computed Tomography for Hepatic Interventions: A Practical Guide JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Tognolini, A., Louie, J., Hwang, G., Hofmann, L., Sze, D., Kothary, N. 2010; 21 (12): 1817-1823

  Abstract

  With adoption of catheter-based techniques that require technically difficult catheterization, the need for imaging platforms that exploit the advantages of multiple modalities and offer three-dimensional visualization has correspondingly increased. At the authors' institution, C-arm computed tomography (CT) is routinely used to complement conventional digital subtraction angiography for transcatheter therapy. The goal of the present report is to share experience with the use of C-arm CT in hepatic interventions, with the aim to provide practical tips for optimizing image acquisition and postprocessing. Although the authors' direct experience is limited to the equipment of a single manufacturer, many of the principles and guidelines can be readily extrapolated to other C-arm CT systems.

  View details for DOI 10.1016/j.jvir.2010.07.027

  View details for PubMedID 20970354

• Renewing Focus on Resident Education: Increased Responsibility and Ownership in Interventional Radiology Rotations Improves the Educational Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Ghatan, C. E., Hwang, G. L., Kuo, W. T., Louie, J. D., Sze, D. Y., Hovsepian, D. M., Desser, T. S., Hofmann, L. V. 2010; 21 (11): 1697-1702

  Abstract

  To enhance the educational experience among residents rotating through interventional radiology (IR) by encouraging ownership and responsibility.In May 2006, the authors implemented changes in resident education in IR that included increased clinical responsibilities, structured didactics, and greater hands-on experience, including call. Residents were assigned as first assistants, ownership of cases was encouraged, and assignment to a week on the consult service was instituted to help residents better understand all aspects of IR practice. Additional faculty recruitment and program expansion ensured the same high level of training for the fellowship program. Evaluations were reviewed every year (July 1, 2007-June 30, 2009) for hands-on training, daily teaching, didactic conferences, and overall effectiveness of the clinical service. A graduated scale of 1-5 was used.In 2009, 3 years after the curricular changes were made, the quality of hands-on training, daily case reviews and consults, didactics, and overall education had markedly improved with 89%, 71%, 65%, and 82% of the residents rating these respective aspects of the training as "above expectations" (4 on a scale of 5) or "superior" (5 on a scale of 5) compared with 77%, 23%, 20%, and 60% in 2005-2006. Three years after the changes, the impact of these changes on recruitment patterns also showed improvement, with 28.6% of the class of 2010 pursuing a fellowship in IR.Increasing resident ownership, responsibility, and hands-on experience improves resident education in IR, which, in turn, promotes interest in the field.

  View details for DOI 10.1016/j.jvir.2010.07.009

  View details for PubMedID 20884234

• Development of New Hepaticoenteric Collateral Pathways after Hepatic Arterial Skeletonization in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Hwang, G. L., Louie, J. D., Kothary, N., Hofmann, L. V., Kuo, W. T., Hovsepian, D. M., Sze, D. Y. 2010; 21 (9): 1385-1395

  Abstract

  Development of new hepaticoenteric anastomotic vessels may occur after endovascular skeletonization of the hepatic artery. Left untreated, they can serve as pathways for nontarget radioembolization. The authors reviewed the incidence, anatomy, management, and significance of collateral vessel formation in patients undergoing radioembolization.One hundred thirty-eight treatments performed on 122 patients were reviewed. Each patient underwent a preparatory digital subtraction angiogram (DSA) and embolization of all hepaticoenteric vessels in preparation for yttrium-90 ((90)Y) administration. Successful skeletonization was verified by C-arm computed tomography (CACT) and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy. During the subsequent treatment session, DSA and CACT were repeated before administration of (90)Y, and the detection of extrahepatic perfusion prompted additional embolization.Forty-two patients (34.4%) undergoing 43 treatments (31.2%) required adjunctive embolization of hepaticoenteric vessels immediately before (90)Y administration. Previous scintigraphy findings showed extrahepatic perfusion in only three cases (7.1%). Vessels were identified by DSA in 54.1%, by CACT in 4.9%, or required both in 41.0%. The time interval between angiograms did not correlate with risk of requiring reembolization (P = .297). A total of 19.7% of vessels were new collateral vessels not visible during the initial angiography. Despite reembolization, three patients (7.1%) had gastric or duodenal ulceration, compared with 1.3% who never had visible collateral vessels, all of whom underwent whole-liver treatment with resin microspheres (P = .038).Development of collateral hepaticoenteric anastomoses occurs after endovascular skeletonization of the hepatic artery. Identified vessels may be managed by adjunctive embolization, but patients appear to remain at increased risk for gastrointestinal complications.

  View details for DOI 10.1016/j.jvir.2010.04.030

  View details for PubMedID 20688531

• Utility of C-arm CT in Patients with Hepatocellular Carcinoma undergoing Transhepatic Arterial Chemoembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Tognolini, A., Louie, J. D., Hwang, G. L., Hofmann, L. V., Sze, D. Y., Kothary, N. 2010; 21 (3): 339-347

  Abstract

  To evaluate the utility of C-arm computed tomography (CT) on treatment algorithms in patients undergoing transhepatic arterial chemoembolization for hepatocellular carcinoma (HCC).From March 2008 to July 2008, 84 consecutive patients with HCC underwent 100 consecutive transhepatic arterial chemoembolizations with iodized oil. Unenhanced and iodinated contrast medium-enhanced C-arm CT with planar and three-dimensional imaging were performed in addition to conventional digital subtraction angiography (DSA) in all patients. The effect on diagnosis and treatment was determined by testing the hypotheses that C-arm CT, in comparison to DSA, provides (a) improved lesion detection, (b) expedient identification and mapping of arterial supply to a tumor, (c) improved characterization of a lesion to allow confident differentiation of HCC from pseudolesions such as arterioportal shunts, and (d) an improved evaluation of treatment completeness. The effect of C-arm CT was analyzed on the basis of information provided with C-arm CT that was not provided or readily apparent at DSA.C-arm CT was technically successful in 93 of the 100 procedures (93%). C-arm CT provided information not apparent or discernible at DSA in 30 of the 84 patients (36%) and resulted in a change in diagnosis, treatment planning, or treatment delivery in 24 (28%). The additional information included, amongst others, visualization of additional or angiographically occult tumors in 13 of the 84 patients (15%) and identification of incomplete treatment in six (7.1%).C-arm CT is a useful collaborative tool in patients undergoing transhepatic arterial chemoembolization and can affect patient care in more than one-fourth of patients.

  View details for DOI 10.1016/j.jvir.2009.11.007

  View details for PubMedID 20133156

• High-risk Retrieval of Adherent and Chronically Implanted IVC Filters: Techniques for Removal and Management of Thrombotic Complications 34th Annual Conference of the Society-of-Interventional-Radiology Kuo, W. T., Tong, R. T., Hwang, G. L., Louie, J. D., Lebowitz, E. A., Sze, D. Y., Hofmann, L. V. ELSEVIER SCIENCE INC. 2009: 1548–56

  Abstract

  To evaluate the safety and efficacy of aggressive techniques for retrieving adherent and chronically implanted inferior vena cava (IVC) filters.A single-center retrospective review was performed on all patients who underwent attempted filter retrieval from October 2007 through October 2008. Patients were included in the study if they had an adherent filter, refractory to standard retrieval techniques, and underwent high-risk retrieval after procedural risks were deemed lower than risks of long-term filter implantation.Fourteen patients were diagnosed with an adherent filter, 13 (93%) of whom were candidates for high-risk retrieval. These patients included seven men and six women (mean age, 40 years; age range, 18-71 years). Nine of the 13 patients (69%) were referred from an outside hospital. Filter retrieval was performed for the following indications: to avoid the risk of long-term thrombotic complications in a young patient (n= 6), to treat symptomatic filter-related IVC stenosis (n= 5), to treat symptomatic filter penetration (n= 1), and to avoid the need for lifelong anticoagulation (n= 1). There were eight Günther-Tulip filters (mean dwell time, 356 days; range 53-1,181 days), two Optease filters (mean dwell time, 62 days; range, 52-72 days), one G2 filter (dwell time, 420 days), and two Recovery filters (mean dwell time, 1,630 days; range, 1,429-1,830 days). Three IVC occlusions necessitated recanalization to facilitate retrieval. High-risk retrieval with use of various techniques with aggressive force was successful in all 13 patients (100%). Partial caval thrombosis occurred in the first four patients (31%) but did not occur after procedural modifications were implemented. There were no complications at clinical follow-up (mean, 221 days; range, 84-452 days).Alternative techniques can be used to retrieve adherent IVC filters implanted for up to 3-5 years. Although caval thrombosis was an observed complication, protocol modifications appeared to reduce this risk.

  View details for DOI 10.1016/j.jvir.2009.08.024

  View details for PubMedID 19864160

• Catheter-directed Therapy for the Treatment of Massive Pulmonary Embolism: Systematic Review and Meta-analysis of Modem Techniques JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Gould, M. K., Louie, J. D., Rosenberg, J. K., Sze, D. Y., Hofmann, L. V. 2009; 20 (11): 1431-1440

  Abstract

  Systemic thrombolysis for the treatment of acute pulmonary embolism (PE) carries an estimated 20% risk of major hemorrhage, including a 3%-5% risk of hemorrhagic stroke. The authors used evidence-based methods to evaluate the safety and effectiveness of modern catheter-directed therapy (CDT) as an alternative treatment for massive PE.The systematic review was initiated by electronic literature searches (MEDLINE, EMBASE) for studies published from January 1990 through September 2008. Inclusion criteria were applied to select patients with acute massive PE treated with modern CDT. Modern techniques were defined as the use of low-profile devices (< or =10 F), mechanical fragmentation and/or aspiration of emboli including rheolytic thrombectomy, and intraclot thrombolytic injection if a local drug was infused. Relevant non-English language articles were translated into English. Paired reviewers assessed study quality and abstracted data. Meta-analysis was performed by using random effects models to calculate pooled estimates for complications and clinical success rates across studies. Clinical success was defined as stabilization of hemodynamics, resolution of hypoxia, and survival to hospital discharge.Five hundred ninety-four patients from 35 studies (six prospective, 29 retrospective) met the criteria for inclusion. The pooled clinical success rate from CDT was 86.5% (95% confidence interval [CI]: 82.1%, 90.2%). Pooled risks of minor and major procedural complications were 7.9% (95% CI: 5.0%, 11.3%) and 2.4% (95% CI: 1.9%, 4.3%), respectively. Data on the use of systemic thrombolysis before CDT were available in 571 patients; 546 of those patients (95%) were treated with CDT as the first adjunct to heparin without previous intravenous thrombolysis.Modern CDT is a relatively safe and effective treatment for acute massive PE. At experienced centers, CDT should be considered as a first-line treatment for patients with massive PE.

  View details for DOI 10.1016/j.jvir.2009.08.002

  View details for PubMedID 19875060

• A Primer on Image-guided Radiation Therapy for the Interventional Radiologist JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Dieterich, S., Louie, J. D., Koong, A. C., Hofmann, L. V., Sze, D. Y. 2009; 20 (7): 859-862

  Abstract

  The use of image-guided radiation therapy in thoracic and abdominal tumors is increasing. Herein, the authors review the process of image-guided radiation therapy and describe techniques useful for optimal implantation of fiducial markers.

  View details for DOI 10.1016/j.jvir.2009.03.037

  View details for PubMedID 19481470

• Incorporating Cone-beam CT into the Treatment Planning for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Louie, J. D., Kothary, N., Kuo, W. T., Hwang, G. L., Hofmann, L. V., Goris, M. L., Iagaru, A. H., Sze, D. Y. 2009; 20 (5): 606-613

  Abstract

  To prepare for yttrium-90 ((90)Y) microsphere radioembolization therapy, digital subtraction angiography (DSA) and technetium- 99m-labeled macroaggregated albumin ((99m)Tc MAA) scintigraphy are used for treatment planning and detection of potential nontarget embolization. The present study was performed to determine if cone-beam computed tomography (CBCT) affects treatment planning as an adjunct to these conventional imaging modalities.From March 2007 to August 2008, 42 consecutive patients (21 men, 21 women; mean age, 59 years; range, 21-75 y) who underwent radioembolization were evaluated by CBCT in addition to DSA and (99m)Tc MAA scintigraphy during treatment planning, and their records were retrospectively reviewed. The contrast-enhanced territories shown by CBCT with selective intraarterial contrast agent administration were used to predict intrahepatic and possible extrahepatic distribution of microspheres.In 22 of 42 cases (52%), extrahepatic enhancement or incomplete tumor perfusion seen on CBCT affected the treatment plan. In 14 patients (33%), the findings were evident exclusively on CBCT and not detected by DSA. When comparing CBCT versus (99m)Tc MAA scintigraphy, CBCT showed eight cases of extrahepatic enhancement (19%) that were not evident on (99m)Tc MAA imaging. CBCT findings directed the additional embolization of vessels or repositioning of the catheter for better contrast agent and microsphere distribution. One case of gastric ulcer from nontarget embolization caused by reader error was observed.CBCT can provide additional information about tumor and tissue perfusion not currently detectable by DSA or (99m)Tc MAA imaging, which should optimize (90)Y microsphere delivery and reduce nontarget embolization.

  View details for DOI 10.1016/j.jvir.2009.01.021

  View details for PubMedID 19345589

• Percutaneous Implantation of Fiducial Markers for Imaging-Guided Radiation Therapy AMERICAN JOURNAL OF ROENTGENOLOGY Kothary, N., Dieterich, S., Louie, J. D., Chang, D. T., Hofmann, L. V., Sze, D. Y. 2009; 192 (4): 1090-1096

  Abstract

  The use of imaging-guided radiation therapy (IGRT) to treat thoracic and abdominal tumors is increasing. In this article, we review the process of IGRT and describe techniques to implant fiducial markers in the optimal geometry.Implantation of fiducial markers can be challenging. A better understanding of the physics of IGRT can help optimize fiducial marker placement for precise tumor targeting.

  View details for DOI 10.2214/AJR.08.1399

  View details for PubMedID 19304719

• Safety and Efficacy of Percutaneous Fiducial Marker Implantation for Image-guided Radiation Therapy JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Heit, J. J., Louie, J. D., Kuo, W. T., Loo, B. W., Koong, A., Chang, D. T., Hovsepian, D., Sze, D. Y., Hofmann, L. V. 2009; 20 (2): 235-239

  Abstract

  To evaluate the safety and technical success rate of percutaneous fiducial marker implantation in preparation for image-guided radiation therapy.From January 2003 to January 2008, we retrospectively reviewed 139 percutaneous fiducial marker implantations in 132 patients. Of the 139 implantations, 44 were in the lung, 61 were in the pancreas, and 34 were in the liver. Procedure-related major and minor complications were documented. Technical success was defined as implantation enabling adequate treatment planning and computed tomographic simulation.The major and minor complication rates were 5% and 17.3%, respectively. Pneumothorax after lung implantation was the most common complication. Pneumothoraces were seen in 20 of the 44 lung implantations (45%); a chest tube was required in only seven of the 44 lung transplantations (16%). Of the 139 implantations, 133 were successful; in six implantations (4.3%) the fiducial markers migrated and required additional procedures or alternate methods of implantation.Percutaneous implantation of fiducial marker is a safe and effective procedure with risks that are similar to those of conventional percutaneous organ biopsy.

  View details for DOI 10.1016/j.jvir.2008.09.026

  View details for PubMedID 19019700

• Catheter-directed embolectomy, fragmentation, and thrombolysis for the treatment of massive pulmonary embolism after failure of systemic thrombolysis CHEST Kuo, W. T., Van den Bosch, M. A., Hofmann, L. V., Louie, J. D., Kothary, N., Sze, D. Y. 2008; 134 (2): 250-254

  Abstract

  The standard medical management for patients in extremis from massive pulmonary embolism (PE) is systemic thrombolysis, but the utility of this treatment relative to catheter-directed intervention (CDI) is unknown. We evaluated the effectiveness of CDI as part of a treatment algorithm for life-threatening PE.A retrospective review was performed on 70 consecutive patients with suspected acute PE over a 10-year period (from 1997 to 2006) who had been referred for pulmonary angiography and/or intervention. The criteria for study inclusion were patients who received CDI due to angiographically confirmed massive PE and hemodynamic shock (shock index, > or = 0.9). CDI involved suction embolectomy and fragmentation with or without catheter thrombolysis.Twelve patients were treated with CDI. There were seven men and five women (mean age, 56 years; age range, 21 to 80 years). Seven patients (58%) were referred for CDI after failing systemic infusion with 100 mg of tissue plasminogen activator, and five patients (42%) had contraindications to systemic thrombolysis. Catheter-directed fragmentation and embolectomy were performed in all patients (100%). Additionally, catheter-guided thrombolysis was performed in eight patients (67%). Technical success was achieved in 12 of 12 cases (100%). There were no major procedural complications (0%). Significant hemodynamic improvement (shock index, < 0.9) was observed in 10 of 12 cases (83%). The remaining two patients (17%) died secondary to cardiac arrest within 24 h. Ten of 12 patients (83%) survived and remained stable until hospital discharge (mean duration, 20 days; range, 3 to 51 days).In the setting of hemodynamic shock from massive PE, CDI is potentially a life-saving treatment for patients who have not responded to or cannot tolerate systemic thrombolysis.

  View details for DOI 10.1378/chest.07-2846

  View details for PubMedID 18682455

• Catheter-directed embolectomy, fragmentation,and thrombolysis for the treatment of massive pulmonary embolim after failure of systemic thrombolysis CHEST 2007 Conference Kuo, W. T., van den Bosch, M. A., Hofmann, L. V., Louie, J. D., Kothary, N., Sze, D. Y. AMER COLL CHEST PHYSICIANS. 2007: 663S–663S

  View details for Web of Science ID 000250282700830