Professional Education

  • Doctor of Philosophy, Leiden University (2016)
  • Master of Science, Vrije Universiteit Amsterdam (2011)
  • Bachelor of Science, Vrije Universiteit Amsterdam (2009)

All Publications

  • Determination of Tumor Margins with Surgical Specimen Mapping Using Near-Infrared Fluorescence. Cancer research Gao, R. W., Teraphongphom, N. T., van den Berg, N. S., Martin, B. A., Oberhelman, N. J., Divi, V., Kaplan, M. J., Hong, S. S., Lu, G., Ertsey, R., Tummers, W. S., Gomez, A. J., Holsinger, F. C., Kong, C. S., Colevas, A. D., Warram, J. M., Rosenthal, E. L. 2018


    For many solid tumors, surgical resection remains the gold standard and tumor-involved margins are associated with poor clinical outcomes. Near-infrared (NIR) fluorescence imaging using molecular agents has shown promise for in situ imaging during resection. However, for cancers with difficult imaging conditions, surgical value may lie in tumor-mapping of surgical specimens. We thus evaluated a novel approach for real-time, intraoperative tumor margin assessment. 21 adult patients with biopsy-confirmed squamous cell carcinoma arising from the head and neck (HNSCC) scheduled for standard-of-care surgery were enrolled. Cohort 1 (n=3) received panitumumab-IRDye800CW at an intravenous microdose of 0.06 mg/kg, cohort 2A (n=5) received 0.5mg/kg, cohort 2B (n=7) received 1mg/kg, and cohort 3 (n=6) received 50 mg. Patients were followed 30 days post-infusion and adverse events were recorded. Imaging was performed using several closed- and wide-field devices. Fluorescence was histologically correlated to determine sensitivity and specificity. In situ imaging demonstrated tumor-to-background ratio (TBR) of 2-3, compared to ex vivo specimen imaging TBR of 5-6. We obtained clear differentiation between tumor and normal tissue, with a three-fold signal difference between positive and negative specimens (p<0.05). We achieved high correlation of fluorescence intensity with tumor location with sensitivities and specificities >89%; fluorescence predicted distance of tumor tissue to the cut surface of the specimen. This novel method of detecting tumor-involved margins in surgical specimens using a cancer-specific agent provides highly sensitive and specific, real-time, intraoperative surgical navigation in resections with complex anatomy which are otherwise less amenable to image guidance.

    View details for DOI 10.1158/0008-5472.CAN-18-0878

    View details for PubMedID 29967260

  • Emerging Intraoperative Imaging Modalities to Improve Surgical Precision. Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging Alam, I. S., Steinberg, I., Vermesh, O., van den Berg, N. S., Rosenthal, E. L., van Dam, G. M., Ntziachristos, V., Gambhir, S. S., Hernot, S., Rogalla, S. 2018


    Intraoperative imaging (IOI) is performed to guide delineation and localization of regions of surgical interest. While oncological surgical planning predominantly utilizes x-ray computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US), intraoperative guidance mainly remains on surgeon interpretation and pathology for confirmation. Over the past decades however, intraoperative guidance has evolved significantly with the emergence of several novel imaging technologies, including fluorescence-, Raman, photoacoustic-, and radio-guided approaches. These modalities have demonstrated the potential to further optimize precision in surgical resection and improve clinical outcomes for patients. Not only can these technologies enhance our understanding of the disease, they can also yield large imaging datasets intraoperatively that can be analyzed by deep learning approaches for more rapid and accurate pathological diagnosis. Unfortunately, many of these novel technologies are still under preclinical or early clinical evaluation. Organizations like the Intra-Operative Imaging Study Group of the European Society for Molecular Imaging (ESMI) support interdisciplinary interactions with the aim to improve technical capabilities in the field, an approach that can succeed only if scientists, engineers, and physicians work closely together with industry and regulatory bodies to resolve roadblocks to clinical translation. In this review, we provide an overview of a variety of novel IOI technologies, discuss their challenges, and present future perspectives on the enormous potential of IOI for oncological surgical navigation.

    View details for DOI 10.1007/s11307-018-1227-6

    View details for PubMedID 29916118

  • Safety of panitumumab-IRDye800CW and cetuximab-IRDye800CW for fluorescence-guided surgical navigation in head and neck cancers THERANOSTICS Gao, R. W., Teraphongphom, N., de Boer, E., van den Berg, N. S., Divi, V., Kaplan, M. J., Oberhelman, N. J., Hong, S. S., Capes, E., Colevas, A., Warram, J. M., Rosenthal, E. L. 2018; 8 (9): 2488–95


    Purpose: To demonstrate the safety and feasibility of leveraging therapeutic antibodies for surgical imaging. Procedures: We conducted two phase I trials for anti-epidermal growth factor receptor antibodies cetuximab-IRDye800CW (n=12) and panitumumab-IRDye800CW (n=15). Adults with biopsy-confirmed head and neck squamous cell carcinoma scheduled for standard-of-care surgery were eligible. For cetuximab-IRDye800CW, cohort 1 was intravenously infused with 2.5 mg/m2, cohort 2 received 25 mg/m2, and cohort 3 received 62.5 mg/m2. For panitumumab-IRDye800CW, cohorts received 0.06 mg/kg, 0.5 mg/kg, and 1 mg/kg, respectively. Electrocardiograms and blood samples were obtained, and patients were followed for 30 days post-study drug infusion. Results: Both fluorescently labeled antibodies had similar pharmacodynamic properties and minimal toxicities. Two infusion reactions occurred with cetuximab and none with panitumumab. There were no grade 2 or higher toxicities attributable to cetuximab-IRDye800CW or panitumumab-IRDye800CW; fifteen grade 1 adverse events occurred with cetuximab-IRDye800CW, and one grade 1 occurred with panitumumab-IRDye800CW. There were no significant differences in QTc prolongation between the two trials (p=0.8). Conclusions: Panitumumab-IRDye800CW and cetuximab-IRDye800CW have toxicity and pharmacodynamic profiles that match the parent compound, suggesting that other therapeutic antibodies may be repurposed as imaging agents with limited preclinical toxicology data.

    View details for DOI 10.7150/thno.24487

    View details for Web of Science ID 000429880400005

    View details for PubMedID 29721094

    View details for PubMedCentralID PMC5928904

  • First-in-human intraoperative near-infrared fluorescence imaging of glioblastoma using cetuximab-IRDye800. Journal of neuro-oncology Miller, S. E., Tummers, W. S., Teraphongphom, N., van den Berg, N. S., Hasan, A., Ertsey, R. D., Nagpal, S., Recht, L. D., Plowey, E. D., Vogel, H., Harsh, G. R., Grant, G. A., Li, G. H., Rosenthal, E. L. 2018


    Maximizing extent of surgical resection with the least morbidity remains critical for survival in glioblastoma patients, and we hypothesize that it can be improved by enhancements in intraoperative tumor detection. In a clinical study, we determined if therapeutic antibodies could be repurposed for intraoperative imaging during resection.Fluorescently labeled cetuximab-IRDye800 was systemically administered to three patients 2 days prior to surgery. Near-infrared fluorescence imaging of tumor and histologically negative peri-tumoral tissue was performed intraoperatively and ex vivo. Fluorescence was measured as mean fluorescence intensity (MFI), and tumor-to-background ratios (TBRs) were calculated by comparing MFIs of tumor and histologically uninvolved tissue.The mean TBR was significantly higher in tumor tissue of contrast-enhancing (CE) tumors on preoperative imaging (4.0 ± 0.5) compared to non-CE tumors (1.2 ± 0.3; p = 0.02). The TBR was higher at a 100 mg dose than at 50 mg (4.3 vs. 3.6). The smallest detectable tumor volume in a closed-field setting was 70 mg with 50 mg of dye and 10 mg with 100 mg. On sections of paraffin embedded tissues, fluorescence positively correlated with histological evidence of tumor. Sensitivity and specificity of tumor fluorescence for viable tumor detection was calculated and fluorescence was found to be highly sensitive (73.0% for 50 mg dose, 98.2% for 100 mg dose) and specific (66.3% for 50 mg dose, 69.8% for 100 mg dose) for viable tumor tissue in CE tumors while normal peri-tumoral tissue showed minimal fluorescence.This first-in-human study demonstrates the feasibility and safety of antibody based imaging for CE glioblastomas.

    View details for DOI 10.1007/s11060-018-2854-0

    View details for PubMedID 29623552

  • Sentinel node biopsy for prostate cancer: report from a consensus panel meeting. BJU international van der Poel, H. G., Wit, E. M., Acar, C., van den Berg, N. S., van Leeuwen, F. W., Valdes Olmos, R. A., Winter, A., Wawroschek, F., Liedberg, F., Maclennan, S., Lam, T. 2017


    To explore the evidence and knowledge gaps in sentinel node biopsy (SNB) in prostate cancer through a consensus panel of experts.A two-round Delphi survey among experts was followed by a consensus panel meeting of 16 experts in February 2016. Agreement voting was performed using the research and development project/University of California, Los Angeles Appropriateness Methodology on 150 statements in nine domains. The disagreement index based on the interpercentile range, adjusted for symmetry score, was used to assess consensus and non-consensus among panel members.Consensus was obtained on 91 of 150 statements (61%). The main outcomes were: (1) the results from an extended lymph node dissection (eLND) are still considered the 'gold standard', and sentinel node (SN) detection should be combined with eLND, at least in patients with intermediate- and high-risk prostate cancer; (2) the role of SN detection in low-risk prostate cancer is unclear; and (3) future studies should contain oncological endpoints as number of positive nodes outside the eLND template, false-negative and false-positive SN procedures, and recurrence-free survival. A high rate of consensus was obtained regarding outcome measures of future clinical trials on SNB (89%). Consensus on tracer technology was only obtained in 47% of statements, reflecting a need for further research and standardization in this area. The low-level evidence in the available literature and the composition of mainly SNB users in the panel constitute the major limitations of the study.Consensus on a majority of elementary statements on SN detection in prostate cancer was obtained.; therefore, the results from this consensus report will provide a basis for the design of further studies in the field. A group of experts identified evidence and knowledge gaps on SN detection in prostate cancer and its application in daily practice. Information from the consensus statements can be used to direct further studies.

    View details for DOI 10.1111/bju.13810

    View details for PubMedID 28188689

  • Sentinel Node Procedure in Prostate Cancer: A Systematic Review to Assess Diagnostic Accuracy. European urology Wit, E. M., Acar, C., Grivas, N., Yuan, C., Horenblas, S., Liedberg, F., Valdes Olmos, R. A., van Leeuwen, F. W., van den Berg, N. S., Winter, A., Wawroschek, F., Hruby, S., Janetschek, G., Vidal-Sicart, S., MacLennan, S., Lam, T. B., van der Poel, H. G. 2017; 71 (4): 596–605


    Extended pelvic lymph node dissection (ePLND) is the gold standard for detecting lymph node (LN) metastases in prostate cancer (PCa). The benefit of sentinel node biopsy (SNB), which is the first draining LN as assessed by imaging of locally injected tracers, remains controversial.To assess the diagnostic accuracy of SNB in PCa.A systematic literature search of Medline, Embase, and the Cochrane Library (1999-2016) was undertaken using PRISMA guidelines. All studies of SNB in men with PCa using PLND as reference standard were included. The primary outcomes were the nondiagnostic rate (NDR), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and false positive (FP) and false negative (FN) rates. Relevant sensitivity analyses based on SN definitions, ePLND as reference standard, and disease risk were undertaken, including a risk of bias (RoB) assessment.Of 373 articles identified, 21 studies recruiting a total of 2509 patients were eligible for inclusion. Median cumulative percentage (interquartile range) results were 4.1% (1.5-10.7%) for NDR, 95.2% (81.8-100%) for sensitivity, 100% (95.0-100%) for specificity, 100% (87.0-100%) for PPV, 98.0% (94.3-100%) for NPV, 0% (0-5.0%) for the FP rate, and 4.8% (0-18.2%) for the FN rate. The findings did not change significantly on sensitivity analyses. Most studies (17/22) had low RoB for index test and reference standard domains.SNB appears to have diagnostic accuracy comparable to ePLND, with high sensitivity, specificity, PPV and NPV, and a low FN rate. With a low FP rate (rate of detecting positive nodes outside the ePLND template), SNB may not have any additional diagnostic value over and above ePLND, although SNB appears to increase nodal yield by increasing the number of affected nodes when combined with ePLND. Thus, in high-risk disease it may be prudent to combine ePLND with SNB.This literature review showed a high diagnostic accuracy for sentinel node biopsy in detecting positive lymph nodes in prostate cancer, but further studies are needed to explore the effect of sentinel node biopsy on complications and oncologic outcome.

    View details for DOI 10.1016/j.eururo.2016.09.007

    View details for PubMedID 27639533

  • Phantom Study Investigating the Accuracy of Manual and Automatic Image Fusion with the GE Logiq E9: Implications for use in Percutaneous Liver Interventions. Cardiovascular and interventional radiology Burgmans, M. C., den Harder, J. M., Meershoek, P., van den Berg, N. S., Chan, S. X., van Leeuwen, F. W., van Erkel, A. R. 2017


    To determine the accuracy of automatic and manual co-registration methods for image fusion of three-dimensional computed tomography (CT) with real-time ultrasonography (US) for image-guided liver interventions.CT images of a skills phantom with liver lesions were acquired and co-registered to US using GE Logiq E9 navigation software. Manual co-registration was compared to automatic and semiautomatic co-registration using an active tracker. Also, manual point registration was compared to plane registration with and without an additional translation point. Finally, comparison was made between manual and automatic selection of reference points. In each experiment, accuracy of the co-registration method was determined by measurement of the residual displacement in phantom lesions by two independent observers.Mean displacements for a superficial and deep liver lesion were comparable after manual and semiautomatic co-registration: 2.4 and 2.0 mm versus 2.0 and 2.5 mm, respectively. Both methods were significantly better than automatic co-registration: 5.9 and 5.2 mm residual displacement (p < 0.001; p < 0.01). The accuracy of manual point registration was higher than that of plane registration, the latter being heavily dependent on accurate matching of axial CT and US images by the operator. Automatic reference point selection resulted in significantly lower registration accuracy compared to manual point selection despite lower root-mean-square deviation (RMSD) values.The accuracy of manual and semiautomatic co-registration is better than that of automatic co-registration. For manual co-registration using a plane, choosing the correct plane orientation is an essential first step in the registration process. Automatic reference point selection based on RMSD values is error-prone.

    View details for DOI 10.1007/s00270-017-1607-3

    View details for PubMedID 28204959

  • Transistor-like pH nanoprobes NATURE BIOMEDICAL ENGINEERING van den Berg, N. S., Rosenthal, E. L. 2017; 1 (1)
  • Hybrid Surgical Guidance: Does Hardware Integration of γ- and Fluorescence Imaging Modalities Make Sense? Journal of nuclear medicine : official publication, Society of Nuclear Medicine KleinJan, G. H., Hellingman, D., van den Berg, N. S., van Oosterom, M. N., Hendricksen, K., Horenblas, S., Valdes Olmos, R. A., van Leeuwen, F. W. 2017; 58 (4): 646–50


    The clinically applied hybrid tracer indocyanine green-(99m)Tc-nanocolloid enables combined radio- and fluorescence image guidance during sentinel node (SN) biopsy procedures. To provide optimal surgical guidance, this tracer requires the presence of both γ- and fluorescence modalities in the operating room. We reasoned that the combination or integration of these modalities could further evolve the hybrid surgical guidance concept. To study this potential, we clinically applied 2 setups that included the combination of γ-detection modalities and an open surgery fluorescence camera. Methods: To attach the fluorescence camera (VITOM) to either a γ-ray detection probe (GP; VITOM-GP) or a portable γ-camera (GC; Vitom GC), clip-on brackets were designed and printed in 3-dimensional sterilizable RC31. Both combined modalities were evaluated in, respectively, 5 and 6 patients with penile cancer during an SN biopsy procedure using indocyanine green-(99m)Tc-nanocolloid. Intraoperatively, radio- and fluorescence-guided SN detection rates were scored at working distances of 0, 10, 20, and 30 cm for both combinations. Results: Using the VITOM-GP combination, we evaluated 9 SNs. γ-tracing rates were shown to be 100%, 88.9%, 55.6%, and 55.6% at a respective working distance of 0, 10, 20, and 30 cm. Detection rates for the fluorescence imaging-based detection were found to be 100%, 77.8%, and 77.8%, at respective working distances of 10, 20, and 30 cm. When the VITOM-GC setup was used, all 10 intraoperatively evaluated SNs could be visualized with the γ-camera independent of the working distance. Fluorescence detection rates were 90%, 80%, and 80% at 10-, 20-, and 30-cm working distances. The integrated detection modalities were shown to work synergistically; overall the, GC was most valuable for rough localization (10- to 30-cm range) of the SNs, the GP for providing convenient real-time acoustic feedback, whereas fluorescence guidance allowed detailed real-time SN visualization. Conclusion: Our findings suggest that full integration of a fluorescence camera with γ-detector (GP or GC) can be of value when a hybrid, radioactive and fluorescent tracer is used.

    View details for DOI 10.2967/jnumed.116.177154

    View details for PubMedID 27688478

  • Toward (Hybrid) Navigation of a Fluorescence Camera in an Open Surgery Setting JOURNAL OF NUCLEAR MEDICINE KleinJan, G. H., van den Berg, N. S., van Oosterom, M. N., Wendler, T., Miwa, M., Bex, A., Hendricksen, K., Horenblas, S., van Leeuwen, F. W. 2016; 57 (10): 1650-1653


    With the introduction of the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid, a direct relation between preoperative imaging and intraoperative fluorescence guidance was established. However, fluorescence guidance remains limited by its superficial nature. This study evaluated the feasibility of a nuclear medicine-based navigation concept that allowed intraoperative positioning of a fluorescence camera (FC) in the vicinity of preoperatively defined ICG-(99m)Tc-nanocolloid containing sentinel nodes (SNs).Five patients with penile cancer scheduled for SN biopsy were injected with ICG-(99m)Tc-nanocolloid followed by preoperative SPECT/CT imaging. The navigation device was used to provide a real-time augmented reality overlay of the SPECT/CT images and video output of the FC. This overlay was then used for FC navigation.SPECT/CT identified 13 SNs in 9 groins. FC navigation was successful for all 12 intraoperatively evaluated SNs (average error, 8.8 mm; range, 0-20 mm).This study reveals the potential benefits of FC navigation during open surgery procedures.

    View details for DOI 10.2967/jnumed.115.171645

    View details for Web of Science ID 000384961900034

    View details for PubMedID 27230927

  • Fluorescence guided surgery and tracer-dose, fact or fiction? EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING KleinJan, G. H., Bunschoten, A., van den Berg, N. S., Olmos, R. A., Klop, W. M., Horenblas, S., van der Poel, H. G., Wester, H., van Leeuwen, F. W. 2016; 43 (10): 1857-1867


    Fluorescence guidance is an upcoming methodology to improve surgical accuracy. Challenging herein is the identification of the minimum dose at which the tracer can be detected with a clinical-grade fluorescence camera. Using a hybrid tracer such as indocyanine green (ICG)-(99m)Tc-nanocolloid, it has become possible to determine the accumulation of tracer and correlate this to intraoperative fluorescence-based identification rates. In the current study, we determined the lower detection limit of tracer at which intraoperative fluorescence guidance was still feasible.Size exclusion chromatography (SEC) provided a laboratory set-up to analyze the chemical content and to simulate the migratory behavior of ICG-nanocolloid in tissue. Tracer accumulation and intraoperative fluorescence detection findings were derived from a retrospective analysis of 20 head-and-neck melanoma patients, 40 penile and 20 prostate cancer patients scheduled for sentinel node (SN) biopsy using ICG-(99m)Tc-nanocolloid. In these patients, following tracer injection, single photon emission computed tomography fused with computed tomography (SPECT/CT) was used to identify the SN(s). The percentage injected dose (% ID), the amount of ICG (in nmol), and the concentration of ICG in the SNs (in μM) was assessed for SNs detected on SPECT/CT and correlated with the intraoperative fluorescence imaging findings.SEC determined that in the hybrid tracer formulation, 41 % (standard deviation: 12 %) of ICG was present in nanocolloid-bound form. In the SNs detected using fluorescence guidance a median of 0.88 % ID was present, compared to a median of 0.25 % ID in the non-fluorescent SNs (p-value < 0.001). The % ID values could be correlated to the amount ICG in a SN (range: 0.003-10.8 nmol) and the concentration of ICG in a SN (range: 0.006-64.6 μM).The ability to provide intraoperative fluorescence guidance is dependent on the amount and concentration of the fluorescent dye accumulated in the lesion(s) of interest. Our findings indicate that intraoperative fluorescence detection with ICG is possible above a μM concentration.

    View details for DOI 10.1007/s00259-016-3372-y

    View details for Web of Science ID 000380700100012

    View details for PubMedID 27020580

  • Hybrid radioguided occult lesion localization (hybrid ROLL) of (18)F-FDG-avid lesions using the hybrid tracer indocyanine green-(99m)Tc-nanocolloid. Revista espan~ola de medicina nuclear e imagen molecular KleinJan, G. H., Brouwer, O. R., Mathéron, H. M., Rietbergen, D. D., Valdés Olmos, R. A., Wouters, M. W., van den Berg, N. S., van Leeuwen, F. W. 2016; 35 (5): 292-297


    To assess if combined fluorescence- and radio-guided occult lesion localization (hybrid ROLL) is feasible in patients scheduled for surgical resection of non-palpable (18)F-FDG-avid lesions on PET/CT.Four patients with (18)F-FDG-avid lesions on follow-up PET/CT that were not palpable during physical examination but were suspected to harbor metastasis were enrolled. Guided by ultrasound, the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was injected centrally in the target lesion. SPECT/CT imaging was used to confirm tracer deposition. Intraoperatively, lesions were localized using a hand-held gamma ray detection probe, a portable gamma camera, and a fluorescence camera. After excision, the gamma camera was used to check the wound bed for residual activity.A total of six (18)F-FDG-avid lymph nodes were identified and scheduled for hybrid ROLL. Comparison of the PET/CT images with the acquired SPECT/CT after hybrid tracer injection confirmed accurate tracer deposition. No side effects were observed. Combined radio- and fluorescence-guidance enabled localization and excision of the target lesion in all patients. Five of the six excised lesions proved tumor-positive at histopathology.The hybrid ROLL approach appears to be feasible and can facilitate the intraoperative localization and excision of non-palpable lesions suspected to harbor tumor metastases. In addition to the initial radioguided detection, the fluorescence component of the hybrid tracer enables high-resolution intraoperative visualization of the target lesion. The procedure needs further evaluation in a larger cohort and wider range of malignancies to substantiate these preliminary findings.

    View details for DOI 10.1016/j.remn.2016.04.001

    View details for PubMedID 27174865

  • Diffusion-weighted-preparation (D-prep) MRI as a future extension of SPECT/CT based surgical planning for sentinel node procedures in the head and neck area? Oral oncology Buckle, T., KleinJan, G. H., Engelen, T., van den Berg, N. S., DeRuiter, M. C., van der Heide, U., Valdes Olmos, R. A., Webb, A., van Buchem, M. A., Balm, A. J., van Leeuwen, F. W. 2016; 60: 48-54


    Even when guided by SPECT/CT planning of nodal resection in the head-and-neck area is challenging due to the many critical anatomical structures present within the surgical field. In this study the potential of a (SPECT/)MRI-based surgical planning method was explored. Hereby MRI increases the identification of SNs within clustered lymph nodes (LNs) and vital structures located adjacent to the SN (such as cranial nerve branches).SPECT/CT and pathology reports from 100 head-and-neck melanoma and 40 oral cavity cancer patients were retrospectively assessed for SN locations in levels I-V and degree of nodal clustering. A diffusion-weighted-preparation magnetic resonance neurography (MRN) sequence was used in eight healthy volunteers to detect LNs and peripheral nerves.In 15% of patients clustered nodes were retrospectively shown to be present at the location where the SN was identified on SPECT/CT (level IIA: 37.2%, level IIB: 21.6% and level III: 15.5%). With MRN, improved LN delineation enabled discrimination of individual LNs within a cluster. Uniquely, this MRI technology also provided insight in LN distribution (23.2±4 LNs per subject) and size (range 21-372mm(3)), and enabled non-invasive assessment of anatomical variances in the location of the LNs and facial nerves.Diffusion-weighted-preparation MRN enabled improved delineation of LNs and their surrounding delicate anatomical structures in the areas that most often harbor SNs in the head-and-neck. Based on our findings a combined SPECT/MRI approach is envisioned for future surgical planning of complex SN resections in this region.

    View details for DOI 10.1016/j.oraloncology.2016.06.015

    View details for PubMedID 27531872

  • (Near-Infrared) Fluorescence-Guided Surgery Under Ambient Light Conditions: A Next Step to Embedment of the Technology in Clinical Routine ANNALS OF SURGICAL ONCOLOGY van den Berg, N. S., Miwa, M., KleinJan, G. H., Sato, T., Maeda, Y., van Akkooi, A. C., Horenblas, S., Karakullukcu, B., van Leeuwen, F. W. 2016; 23 (8): 2586-2595


    In open surgery procedures, after temporarily dimming the lights in the operation theatre, the Photo Dynamic Eye (PDE) fluorescence camera has, amongst others, been used for fluorescence-guided sentinel node (SN) biopsy procedures. To improve the clinical utility and logistics of fluorescence-guided surgery, we developed and evaluated a prototype modified PDE (m-PDE) fluorescence camera system.The m-PDE works under ambient light conditions and includes a white light mode and a pseudo-green-colored fluorescence mode (including a gray-scaled anatomical background). Twenty-seven patients scheduled for SN biopsy for (head and neck) melanoma (n = 16), oral cavity (n = 6), or penile (n = 5) cancer were included. The number and location of SNs were determined following an indocyanine green-(99m)Tc-nanocolloid injection and preoperative imaging. Intraoperatively, fluorescence guidance was used to visualize the SNs. The m-PDE and conventional PDE were compared head-to-head in a phantom study, and in seven patients. In the remaining 20 patients, only the m-PDE was evaluated.Phantom study: The m-PDE was superior over the conventional PDE, with a detection sensitivity of 1.20 × 10(-11) M (vs. 3.08 × 10(-9) M) ICG in human serum albumin. In the head-to-head clinical comparison (n = 7), the m-PDE was also superior: (i) SN visualization: 100 versus 81.4 %; (ii) transcutaneous SN visualization: 40.7 versus 22.2 %; and (iii) lymphatic duct visualization: 7.4 versus 0 %. Findings were further underlined in the 20 additionally included patients.The m-PDE enhanced fluorescence imaging properties compared with its predecessor, and provides a next step towards routine integration of real-time fluorescence guidance in open surgery.

    View details for DOI 10.1245/s10434-016-5186-3

    View details for Web of Science ID 000379189900033

    View details for PubMedID 27020586

  • A pilot study of SPECT/CT-based mixed-reality navigation towards the sentinel node in patients with melanoma or Merkel cell carcinoma of a lower extremity NUCLEAR MEDICINE COMMUNICATIONS van den Berg, N. S., Engelen, T., Brouwer, O. R., Matheron, H. M., Valdes-Olmos, R. A., Nieweg, O. E., van Leeuwen, F. W. 2016; 37 (8): 812-817


    To explore the feasibility of an intraoperative navigation technology based on preoperatively acquired single photon emission computed tomography combined with computed tomography (SPECT/CT) images during sentinel node (SN) biopsy in patients with melanoma or Merkel cell carcinoma.Patients with a melanoma (n=4) or Merkel cell carcinoma (n=1) of a lower extremity scheduled for wide re-excision of the primary lesion site and SN biopsy were studied. Following a Tc-nanocolloid injection and lymphoscintigraphy, SPECT/CT images were acquired with a reference target (ReTp) fixed on the leg or the iliac spine. Intraoperatively, a sterile ReTp was placed at the same site to enable SPECT/CT-based mixed-reality navigation of a gamma ray detection probe also containing a reference target (ReTgp).The accuracy of the navigation procedure was determined in the coronal plane (x, y-axis) by measuring the discrepancy between standard gamma probe-based SN localization and mixed-reality-based navigation to the SN. To determine the depth accuracy (z-axis), the depth estimation provided by the navigation system was compared to the skin surface-to-node distance measured in the computed tomography component of the SPECT/CT images.In four of five patients, it was possible to navigate towards the preoperatively defined SN. The average navigational error was 8.0 mm in the sagittal direction and 8.5 mm in the coronal direction. Intraoperative sterile ReTp positioning and tissue movement during surgery exerted a distinct influence on the accuracy of navigation.Intraoperative navigation during melanoma or Merkel cell carcinoma surgery is feasible and can provide the surgeon with an interactive 3D roadmap towards the SN or SNs in the groin. However, further technical optimization of the modality is required before this technology can become routine practice.

    View details for DOI 10.1097/MNM.0000000000000524

    View details for Web of Science ID 000380110500005

    View details for PubMedID 27076206

  • Navigation of a robot-integrated fluorescence laparoscope in preoperative SPECT/CT and intraoperative freehand SPECT imaging data: a phantom study. Journal of biomedical optics van Oosterom, M. N., Engelen, M. A., van den Berg, N. S., KleinJan, G. H., van der Poel, H. G., Wendler, T., van de Velde, C. J., Navab, N., van Leeuwen, F. W. 2016; 21 (8): 86008-?

    View details for DOI 10.1117/1.JBO.21.8.086008

    View details for PubMedID 27548770

  • Multimodal hybrid imaging agents for sentinel node mapping as a means to (re)connect nuclear medicine to advances made in robot-assisted surgery EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING KleinJan, G. H., van den Berg, N. S., De Jong, J., Wit, E. M., Thygessen, H., Vegt, E., van der Poel, H. G., van Leeuwen, F. W. 2016; 43 (7): 1278-1287


    Radical prostatectomy and complementary extended pelvic lymph node dissection (ePLND) of sentinel lymph nodes (SNs) and non-sentinel lymph nodes (LNs) at risk of containing metastases are increasingly being performed using high-tech robot-assisted approaches. Although this technological evolution has clear advantages, the physical nature of robotic systems limits the integrated use of routine radioguided surgery technologies. Hence, engineering effort in robotics are focused on the integration of fluorescence guidance technologies. Using the hybrid SN tracer indocyanine green-(99m)Tc-nanocolloid (radioactive and fluorescent), for the first time in combination with a robot-integrated laparoscope, we investigated whether the robot-assisted approach affects the accuracy of fluorescence detection of SNs identified preoperatively using nuclear medicine.The study included 55 patients (Briganti nomogram-based risk >5 % on LN metastases) scheduled for robot-assisted radical prostatectomy, SN biopsy and ePLND. Following indocyanine green-(99m)Tc-nanocolloid injection, preoperative nuclear imaging (lymphoscintigraphy and SPECT/CT) was used to locate the SN(s). The fluorescence laparoscope was used intraoperatively to identify the SN(s) with standard fluorescence settings (in 50 patients) and with customized settings (in 5 patients). The number and location of the SNs, the radioactive, fluorescence (both in vivo and ex vivo) and tumour status of the resected SNs/LNs, and postoperative complications were recorded and analysed.Combined, preoperative lymphoscintigraphy and SPECT/CT imaging identified 212 SNs (median 4 per patient). Intraoperative fluorescence imaging using standard fluorescence settings visualized 80.4 % (148/184 SNs; 50 patients; ex vivo 97.8 %). This increased to 85.7 % (12/14 SNs; 5 patients; ex vivo 100 %) with customized fluorescence settings. SPECT/CT images provided guidance towards the residual SNs. Ex vivo all removed SNs were radioactive. SNs were tumour-positive in 25.4 % of patients (14/55; false-negative rate 7 %, 1/14 patients). In ten patients, the SN was the only tumour-positive LN. Surgical complications were minimal.Directly linking 3D preoperative nuclear imaging information on SNs to a robot-integrated fluorescence laparoscope improved the surgeon's use of the technology and did not influence the sensitivity or morbidity of the procedure. To our surprise, however, the detection rates with the current fluorescence camera did not improve.

    View details for DOI 10.1007/s00259-015-3292-2

    View details for Web of Science ID 000376246200010

    View details for PubMedID 26768422

  • Tailoring Fluorescent Dyes To Optimize a Hybrid RGD-Tracer BIOCONJUGATE CHEMISTRY Bunschoten, A., van Willigen, D. M., Buckle, T., van den Berg, N. S., Welling, M. M., Spa, S. J., Wester, H., van Leeuwen, F. W. 2016; 27 (5): 1253-1258


    Quantitative assessment of affinity and kinetics is a critical component in the development of (receptor-targeted) radiotracers. For fluorescent tracers, such an assessment is currently not yet applied, while (small) changes in chemical composition of the fluorescent component might have substantial influence on the overall properties of a fluorescent tracer. Hybrid imaging labels that contain both a radiolabel and a fluorescent dye can be used to evaluate both the affinity (fluorescent label) and the in vivo distribution (radiolabel) of a targeted tracer. We present a hybrid label oriented and matrix-based scoring approach that enabled quantitative assessment of the influence of (overall) charge and lipophilicity of the fluorescent label on the (in vivo) characteristics of αvβ3-integrin targeted tracers. Systematic chemical alterations in the fluorescent dye were shown to result in a clear difference in the in vivo distribution of the different hybrid tracers. The applied evaluation technique resulted in an optimized targeted tracer for αvβ3-integrin, which combined the highest T/M ratio with the lowest uptake in other organs. Obviously this selection concept would also be applicable during the development of other (receptor-targeted) imaging tracers.

    View details for DOI 10.1021/acs.bioconjchem.6b00093

    View details for Web of Science ID 000376331700011

    View details for PubMedID 27074375

  • First Robotic SPECT for Minimally Invasive Sentinel Lymph Node Mapping IEEE TRANSACTIONS ON MEDICAL IMAGING Fuerst, B., Sprung, J., Pinto, F., Frisch, B., Wendler, T., Simon, H., Mengus, L., van den Berg, N. S., van der Poel, H. G., van Leeuwen, F. W., Navab, N. 2016; 35 (3): 830-838


    In this paper we present the usage of a drop-in gamma probe for intra-operative Single-Photon Emission Computed Tomography (SPECT) imaging in the scope of minimally invasive robot-assisted interventions. The probe is designed to be inserted and reside inside the abdominal cavity during the intervention. It is grasped during the procedure using a robotic laparoscopic gripper enabling full six degrees of freedom handling by the surgeon. We demonstrate the first deployment of the tracked probe for intra-operative in-patient robotic SPECT enabling augmented-reality image guidance. The hybrid mechanical- and image-based in-patient probe tracking is shown to have an accuracy of 0.2 mm. The overall system performance is evaluated and tested with a phantom for gynecological sentinel lymph node interventions and compared to ground-truth data yielding a mean reconstruction accuracy of 0.67 mm.

    View details for DOI 10.1109/TMI.2015.2498125

    View details for Web of Science ID 000372369700011

    View details for PubMedID 26561283

  • Multispectral Fluorescence Imaging During Robot-assisted Laparoscopic Sentinel Node Biopsy: A First Step Towards a Fluorescence-based Anatomic Roadmap. European urology van den Berg, N. S., Buckle, T., KleinJan, G. H., van der Poel, H. G., van Leeuwen, F. W. 2016


    During (robot-assisted) sentinel node (SN) biopsy procedures, intraoperative fluorescence imaging can be used to enhance radioguided SN excision. For this combined pre- and intraoperative SN identification was realized using the hybrid SN tracer, indocyanine green-(99m)Tc-nanocolloid. Combining this dedicated SN tracer with a lymphangiographic tracer such as fluorescein may further enhance the accuracy of SN biopsy.Clinical evaluation of a multispectral fluorescence guided surgery approach using the dedicated SN tracer ICG-(99m)Tc-nanocolloid, the lymphangiographic tracer fluorescein, and a commercially available fluorescence laparoscope.Pilot study in ten patients with prostate cancer. Following ICG-(99m)Tc-nanocolloid administration and preoperative lymphoscintigraphy and single-photon emission computed tomograpy imaging, the number and location of SNs were determined. Fluorescein was injected intraprostatically immediately after the patient was anesthetized. A multispectral fluorescence laparoscope was used intraoperatively to identify both fluorescent signatures.Multispectral fluorescence imaging during robot-assisted radical prostatectomy with extended pelvic lymph node dissection and SN biopsy.(1) Number and location of preoperatively identified SNs. (2) Number and location of SNs intraoperatively identified via ICG-(99m)Tc-nanocolloid imaging. (3) Rate of intraoperative lymphatic duct identification via fluorescein imaging. (4) Tumor status of excised (sentinel) lymph node(s). (5) Postoperative complications and follow-up.Near-infrared fluorescence imaging of ICG-(99m)Tc-nanocolloid visualized 85.3% of the SNs. In 8/10 patients, fluorescein imaging allowed bright and accurate identification of lymphatic ducts, although higher background staining and tracer washout were observed. The main limitation is the small patient population.Our findings indicate that a lymphangiographic tracer can provide additional information during SN biopsy based on ICG-(99m)Tc-nanocolloid. The study suggests that multispectral fluorescence image-guided surgery is clinically feasible.We evaluated the concept of surgical fluorescence guidance using differently colored dyes that visualize complementary features. In the future this concept may provide better guidance towards diseased tissue while sparing healthy tissue, and could thus improve functional and oncologic outcomes.

    View details for DOI 10.1016/j.eururo.2016.06.012

    View details for PubMedID 27345689

  • Revolutionizing (robot-assisted) laparoscopic gamma tracing using a drop-in gamma probe technology. American journal of nuclear medicine and molecular imaging van Oosterom, M. N., Simon, H., Mengus, L., Welling, M. M., van der Poel, H. G., van den Berg, N. S., van Leeuwen, F. W. 2016; 6 (1): 1-17


    In complex (robot-assisted) laparoscopic radioguided surgery procedures, or when low activity lesions are located nearby a high activity background, the limited maneuverability of a laparoscopic gamma probe (LGP; 4 degrees of freedom (DOF)) may hinder lesion identification. We investigated a drop-in gamma probe (DIGP) technology to be inserted via a trocar, after which the laparoscopic surgical tool at hand can pick it up and maneuver it. Phantom experiments showed that distinguishing a low objective from a high background source (1:100 ratio) was only possible with the detector faced >90° from the high background source. Signal-low-objective-to-background ratios of 3.77, 2.01 and 1.84 were found for detector angles of 90°, 135° and 180°, respectively, whereas detector angles of 0° and 45° were unable to distinguish the sources. This underlines the critical role probe positioning plays. We then focused on engineering of the gripping part for optimal DIGP pick-up with a conventional laparoscopic forceps (4 DOF) or a robotic forceps (6 DOF). DIGPs with 0°, 45°, 90°, and 135° -grip orientations were designed, and their maneuverability- and scanning direction were evaluated and compared to a conventional LGP. The maneuverability- and scanning direction of the DIGP was found highest when using the robotic forceps, with the largest effective scanning direction range obtained with the 90° -grip design (0-180° versus 0-111°, 0-140°, and 37-180° for 0°, 45° and 135° -grip designs, respectively). For the laparoscopic forceps, the scan direction directly translated from the angle of the grip design with the advantage that the 135° -gripped DIGP could be faced backwards (not possible with the conventional LGP). In the ex vivo clinical setup, the surgeon rated DIGP pick-up most convenient for the 45°-grip design. Concluding, the DIGP technology was successfully introduced. Optimization of the grip design and grasping angle of the DIGP increased its utility for (robot-assisted) laparoscopic gamma tracing.

    View details for PubMedID 27069762

  • Fluorescent radiocolloids: are hybrid tracers the future for lymphatic mapping? EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING Vidal-Sicart, S., van Leeuwen, F. W., van den Berg, N. S., Olmos, R. A. 2015; 42 (11): 1627-1630

    View details for DOI 10.1007/s00259-015-3132-4

    View details for Web of Science ID 000361996100002

    View details for PubMedID 26194719

  • First-in-human evaluation of a hybrid modality that allows combined radio- and (near-infrared) fluorescence tracing during surgery EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING van den Berg, N. S., Simon, H., KleinJan, G. H., Engelen, T., Bunschoten, A., Welling, M. M., Tijink, B. M., Horenblas, S., Chambron, J., van Leeuwen, F. W. 2015; 42 (11): 1639-1647


    The clinical introduction of the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid, composed of a radioactive and a near-infrared (NIR) fluorescence component, has created the need for surgical (imaging) modalities that allow for simultaneous detection of both signals. This study describes the first-in-human use of a prototype opto-nuclear probe during sentinel node (SN) biopsy using ICG-(99m)Tc-nanocolloid.To allow for fluorescence tracing, a derivative of the conventional gamma probe technology was generated in which two optical fibers were integrated to allow for excitation (785 nm) and emission signal collection (> 810 nm). The ability of this opto-nuclear probe to detect the fluorescence signal of the hybrid tracer ICG-(99m)Tc-nanocolloid was firstly determined ex vivo in (non)SNs samples obtained from 41 patients who underwent hybrid tracer-based SN biopsy in the head and neck or urogenital area. In an in vivo proof-of-concept study in nine of these 41 patients, SNs were localized using combined gamma and fluorescence tracing with the opto-nuclear probe. Fluorescence tracing was performed in a similar manner as gamma tracing and under ambient light conditions.Ex vivo, the gamma tracing option of the opto-nuclear probe correctly identified the SN in all 150 evaluated (non)SN samples. Ex vivo fluorescence tracing in the low-sensitivity mode correctly identified 71.7% of the samples. This increased to 98.9% when fluorescence tracing was performed in the high-sensitivity mode. In vivo fluorescence tracing (high-sensitivity mode) accurately identified the SNs in all nine patients (20 SNs evaluated; 100%).This study demonstrates the first-in-human evaluation of a hybrid modality capable of detecting both gamma and fluorescence signals during a surgical procedure. Fluorescence tracing could be performed in ambient light.

    View details for DOI 10.1007/s00259-015-3109-3

    View details for Web of Science ID 000361996100004

    View details for PubMedID 26109329

  • Advances in sentinel node dissection in prostate cancer from a technical perspective INTERNATIONAL JOURNAL OF UROLOGY Acar, C., KleinJan, G. H., van den Berg, N. S., Wit, E. M., van Leeuwen, F. W., van der Poel, H. G. 2015; 22 (10): 898-909


    The most important feature of sentinel node biopsy for prostate cancer procedure is that staging can be improved. Sentinel nodes might be found outside the extended pelvic lymph node dissection template what renders the sentinel node additive of extended pelvic lymph node dissection. At the same time, staging within the template can be further refined. We reviewed the literature regarding the sentinel node biopsy procedure for prostate cancer. PubMed and Embase were searched for all English-language publications from January 1999 to September 2014 by using the keywords as "prostate cancer" and "sentinel lymph node" plus "biopsy" "dissection" and/or "procedure." The present review discusses step-by-step sentinel node biopsy for prostate cancer. Topics of discussion are: (i) preoperative sentinel node mapping (tracers and imaging); (ii) intraoperative sentinel node identification (surgical procedure and outcome); and (iii) novelties to improve sentinel node identification (pre- and intraoperative approaches). Conventional sentinel node mapping is carried out after the injection of a (99m) Tc-based tracer and subsequent preoperative imaging; for example, lymphoscintigraphy and single-photon emission computed tomography/computed tomography. This approach allowed the detection of sentinel nodes outside the extended lymph node dissection template in 3.6-36% of men with intermediate- and high-risk prostate cancer. Hereby, an overall false negative rate of sentinel nodes was reported between 0% and 24.4%. To further refine the intraoperative sampling procedure, novel imaging methods such as fluorescence imaging have been introduced. Prospective randomized comparison studies are required to confirm the added benefit of sentinel template directed nodal dissection. A proper and obtainable end-point of such a study could be the number of removed positive nodes for carrying out nodal dissection with or without sentinel template directed dissection. Similarly, the clinical impact of novel imaging technologies requires further investigation.

    View details for DOI 10.1111/iju.12863

    View details for Web of Science ID 000362456800002

    View details for PubMedID 26173593

  • Multimodal Surgical Guidance during Sentinel Node Biopsy for Melanoma: Combined Gamma Tracing and Fluorescence Imaging of the Sentinel Node through Use of the Hybrid Tracer Indocyanine Green-(99m)Tc-Nanocolloid. Radiology van den Berg, N. S., Brouwer, O. R., Schaafsma, B. E., Mathéron, H. M., Klop, W. M., Balm, A. J., van Tinteren, H., Nieweg, O. E., van Leeuwen, F. W., Valdés Olmos, R. A. 2015; 275 (2): 521-529


    Purpose To evaluate the hybrid approach in a large population of patients with melanoma in the head and neck, on the trunk, or on an extremity who were scheduled for sentinel node (SN) biopsy. Materials and Methods This prospective study was approved by the institutional review board. Between March 2010 and March 2013, 104 patients with a melanoma, including 48 women (average age, 54.3 years; range, 18.5-87.4 years) and 56 men (average age, 55.2 years; range, 22.4-77.4 years) (P = .76) were enrolled after obtaining written informed consent. Following intradermal hybrid tracer administration, lymphoscintigraphy and single photon emission computed tomography/computed tomography were performed. Blue dye was intradermally injected prior to the start of the surgical operation (excluding patients with a facial melanoma). Intraoperatively, SNs were initially pursued by using gamma tracing followed by fluorescence imaging (FI) and, when applicable, blue-dye detection. A portable gamma camera was used to confirm SN removal. Collected data included number and location of the preoperatively and intraoperatively identified SNs and the intraoperative number of SNs that were radioactive, fluorescent, and blue. A two-sample test for equality of proportions was performed to evaluate differences in intraoperative SN visualization through FI and blue-dye detection. Results Preoperative imaging revealed 2.4 SNs (range, 1-6) per patient. Intraoperatively, 93.8% (286 of 305) of the SNs were radioactive, 96.7% (295 of 305) of the SNs were fluorescent, while only 61.7% (116 of 188) of the SNs stained blue (P < .0001). FI was of value for identification of near-injection-site SNs (two patients), SNs located in complex anatomic areas (head and neck [28 patients]), and SNs that failed to accumulate blue dye (19 patients). Conclusion The hybrid tracer enables both preoperative SN mapping and intraoperative SN identification in melanoma patients. In the setup of this study, optical identification of the SNs through the fluorescent signature of the hybrid tracer was superior compared with blue dye-based SN visualization.

    View details for DOI 10.1148/radiol.14140322

    View details for PubMedID 25521776

  • Utility of SPECT/CT scan for anatomical localization of pararectal and presacral sentinel nodes in prostate cancer REVISTA ESPANOLA DE MEDICINA NUCLEAR E IMAGEN MOLECULAR Chicharo de Freitas, J. R., KleinJan, G. H., van der Poel, H. G., van den Berg, N. S., Vegt, E., Stokkel, M. P., Olmos, R. A. 2015; 34 (1): 19-23


    This study has aimed to evaluate the added value of SPECT-CT scan in the preoperative assessment of sentinel nodes of the presacral and pararectal regions localized outside the standard area of extended pelvic lymphadenectomy for the staging of the pelvis in prostate cancer. SPECT-CT scan can serve as a guide for the excision of these nodes by lymphadenectomy by open surgery or laparoscopy.We evaluated 4 patients with prostate cancer presenting sentinel nodes in the pararectal and presacral regions on SPECT-CT scan performed in addition to lymphoscintigraphy. These patients underwent lymphadenectomy with robot-assisted laparoscopy together with prostatectomy. All of the excised lymph nodes were sent for histopathology study.An average of 6 sentinel nodes per patient were found on SPECT-CT scan with a mean of 2 sentinel nodes in presacral/pararectal región. Lymphadenectomy including these areas was performed. Pararectal/presacral sentinel nodes of all patients depicted by SPECT-CT scan were tumor free on histopathology study. Sentinel nodes (no pararectal/presacral) were positive for malignancy in only one patient.Preoperative SPECT-CT scan is a useful tool to localize the sentinel nodes in pararectal/presacral regions. It can be an anatomic guide for new modalities of laparoscopic surgery such as robot-assisted procedures that can access the pelvic areas visualized with SPECT-CT scan, making excision of these nodes possible.

    View details for DOI 10.1016/j.remn.2014.09.001

    View details for Web of Science ID 000348696200004

    View details for PubMedID 25448419

  • The next evolution in radioguided surgery: breast cancer related sentinel node localization using a freehandSPECT-mobile gamma camera combination. American journal of nuclear medicine and molecular imaging Engelen, T., Winkel, B. M., Rietbergen, D. D., KleinJan, G. H., Vidal-Sicart, S., Olmos, R. A., van den Berg, N. S., van Leeuwen, F. W. 2015; 5 (3): 233-245


    Accurate pre- and intraoperative identification of the sentinel node (SN) forms the basis of the SN biopsy procedure. Gamma tracing technologies such as a gamma probe (GP), a 2D mobile gamma camera (MGC) or 3D freehandSPECT (FHS) can be used to provide the surgeon with radioguidance to the SN(s). We reasoned that integrated use of these technologies results in the generation of a "hybrid" modality that combines the best that the individual radioguidance technologies have to offer. The sensitivity and resolvability of both 2D-MGC and 3D-FHS-MGC were studied in a phantom setup (at various source-detector depths and using varying injection site-to-SN distances), and in ten breast cancer patients scheduled for SN biopsy. Acquired 3D-FHS-MGC images were overlaid with the position of the phantom/patient. This augmented-reality overview image was then used for navigation to the hotspot/SN in virtual-reality using the GP. Obtained results were compared to conventional gamma camera lymphoscintigrams. Resolution of 3D-FHS-MGC allowed identification of the SNs at a minimum injection site (100 MBq)-to-node (1 MBq; 1%) distance of 20 mm, up to a source-detector depth of 36 mm in 2D-MGC and up to 24 mm in 3D-FHS-MGC. A clinically relevant dose of approximately 1 MBq was clearly detectable up to a depth of 60 mm in 2D-MGC and 48 mm in 3D-FHS-MGC. In all ten patients at least one SN was visualized on the lymphoscintigrams with a total of 12 SNs visualized. 3D-FHS-MGC identified 11 of 12 SNs and allowed navigation to all these visualized SNs; in one patient with two axillary SNs located closely to each other (11 mm), 3D-FHS-MGC was not able to distinguish the two SNs. In conclusion, high sensitivity detection of SNs at an injection site-to-node distance of 20 mm-and-up was possible using 3D-FHS-MGC. In patients, 3D-FHS-MGC showed highly reproducible images as compared to the conventional lymphoscintigrams.

    View details for PubMedID 26069857

  • Optimisation of Fluorescence Guidance During Robot-assisted Laparoscopic Sentinel Node Biopsy for Prostate Cancer EUROPEAN UROLOGY KleinJan, G. H., van den Berg, N. S., Brouwer, O. R., De Jong, J., Acar, C., Wit, E. M., Vegt, E., van der Noort, V., Olmos, R. A., van Leeuwen, F. W., van der Poel, H. G. 2014; 66 (6): 991-998


    The hybrid tracer was introduced to complement intraoperative radiotracing towards the sentinel nodes (SNs) with fluorescence guidance.Improve in vivo fluorescence-based SN identification for prostate cancer by optimising hybrid tracer preparation, injection technique, and fluorescence imaging hardware.Forty patients with a Briganti nomogram-based risk >10% of lymph node (LN) metastases were included. After intraprostatic tracer injection, SN mapping was performed (lymphoscintigraphy and single-photon emission computed tomography with computed tomography (SPECT-CT)). In groups 1 and 2, SNs were pursued intraoperatively using a laparoscopic gamma probe followed by fluorescence imaging (FI). In group 3, SNs were initially located via FI. Compared with group 1, in groups 2 and 3, a new tracer formulation was introduced that had a reduced total injected volume (2.0 ml vs. 3.2 ml) but increased particle concentration. For groups 1 and 2, the Tricam SLII with D-Light C laparoscopic FI (LFI) system was used. In group 3, the LFI system was upgraded to an Image 1 HUB HD with D-Light P system.Hybrid tracer-based SN biopsy, extended pelvic lymph node dissection, and robot-assisted radical prostatectomy.Number and location of the preoperatively identified SNs, in vivo fluorescence-based SN identification rate, tumour status of SNs and LNs, postoperative complications, and biochemical recurrence (BCR).Mean fluorescence-based SN identification improved from 63.7% (group 1) to 85.2% and 93.5% for groups 2 and 3, respectively (p=0.012). No differences in postoperative complications were found. BCR occurred in three pN0 patients.Stepwise optimisation of the hybrid tracer formulation and the LFI system led to a significant improvement in fluorescence-assisted SN identification. Preoperative SPECT-CT remained essential for guiding intraoperative SN localisation.Intraoperative fluorescence-based SN visualisation can be improved by enhancing the hybrid tracer formulation and laparoscopic fluorescence imaging system.

    View details for DOI 10.1016/j.eururo.2014.07.014

    View details for Web of Science ID 000344694300015

    View details for PubMedID 25092539

  • Reply from authors re: Francesco Montorsi, Giorgio Gandaglia. Sentinel node biopsy for prostate cancer: a useless surgical exercise? Eur urol 2014;66:999-1000: Removing nodes that count rather than counting nodes that don't. European urology van der Poel, H. G., van den Berg, N. S., KleinJan, G. H., van Leeuwen, F. W. 2014; 66 (6): 1000-1001

    View details for DOI 10.1016/j.eururo.2014.10.005

    View details for PubMedID 25440526

  • Feasibility of intraoperative navigation to the sentinel node in the groin using preoperatively acquired single photon emission computerized tomography data: transferring functional imaging to the operating room. journal of urology Brouwer, O. R., van den Berg, N. S., Mathéron, H. M., Wendler, T., van der Poel, H. G., Horenblas, S., Valdés Olmos, R. A., van Leeuwen, F. W. 2014; 192 (6): 1810-1816


    We explored the clinical feasibility and accuracy of intraoperative navigation based on preoperatively acquired 3-dimensional functional imaging data.Ten patients with penile carcinoma scheduled for sentinel node biopsy were prospectively included in study. After tracer injection preoperative single photon emission computerized tomography/computerized tomography was performed with a reference target fixed on the patient. Repositioning a sterile reference target shortly before surgery allowed 3-dimensional single photon emission computerized tomography/computerized tomography mixed reality based navigation of the γ probe (also containing a reference target) to the sentinel node. The accuracy of the declipse®SPECT navigation approach was determined in relation to the incision site indicated by the conventional γ probe in the coronal plane and the depth estimation measured on axial computerized tomography slices in the sagittal/axial plane.The 3-dimensional mixed reality approach enabled γ probe navigation toward the sentinel node in all 10 patients. The average ± SD navigation error in the coronal and saggital/axial planes was 5.0 ± 3.9 and 5.3 ± 3.9 mm, respectively.To our knowledge this is the first study demonstrating the feasibility of intraoperative navigation based on preoperatively acquired 3-dimensional single photon emission computerized tomography/computerized tomography images. Although confirmation of successful target localization (eg using γ tracing or fluorescence imaging) remains indispensable, this opens the way to translate 3-dimensional functional imaging data to the operating room.

    View details for DOI 10.1016/j.juro.2014.03.127

    View details for PubMedID 25066868

  • An innovative multimodality approach for sentinel node mapping and biopsy in head and neck malignancies REVISTA ESPANOLA DE MEDICINA NUCLEAR E IMAGEN MOLECULAR Borbon-Arce, M., Brouwer, O. R., van den Berg, N. S., Matheron, H., Klop, W. M., Balm, A. J., van Leeuwen, F. W., Valdes-Olmos, R. A. 2014; 33 (5): 274-279


    Recent innovations such as preoperative SPECT/CT, intraoperative imaging using portable devices and a hybrid tracer were evaluated in a multimodality approach for sentinel node (SN) mapping and biopsy in head and neck malignancies.The evaluation included 25 consecutive patients with head and neck malignancies (16 melanomas and 9 oral cavity squamous cell carcinomas). Patients were peritumorally injected with the hybrid tracer ICG-(99m)Tc-nanocolloid. SNs were initially identified with lymphoscintigraphy followed by single photon emission computed tomography (SPECT/CT) 2 hours after tracer administration. During surgery a portable gamma camera in combination with a near-infrared fluorescence camera was used in addition to a handheld gamma ray detection probe to locate the SNs.In all patients the use of conventional lymphoscintigraphy, SPECT/CT and the additional help of the portable gamma camera in one case were able to depict a total of 67 SNs (55 of them visualized on planar images, 11 additional on SPECT/CT and 1 additional with the portable gamma camera). A total of 67 of the preoperatively defined SNs together with 22 additional SNs were removed intraoperatively; 12 out of the 22 additional SNs found during operation were located in the vicinity of the injection site in anatomical areas such as the periauricular or submental regions. The other 10 additional SNs were found by radioguided post-resection control of the excision SN site.In the present series 26% additional SNs were found using the multimodal approach, that incorporates SPECT/CT and intraoperative imaging to the conventional procedure. This approach appears to be useful in malignancies located close to the area of lymphatic drainage such as the periauricular area and the oral cavity.

    View details for DOI 10.1016/j.remn.2013.11.005

    View details for Web of Science ID 000341804800004

    View details for PubMedID 24842707

  • Hybrid tracers for sentinel node biopsy QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING van den Berg, N. S., Buckle, T., Kleinjan, G. I., Klop, W. M., Horenblas, S., van der Poel, H. G., Valdes-Olmos, R. A., Van Leeuwen, F. I. 2014; 58 (2): 193-206


    Conventional sentinel node (SN) mapping is performed by injection of a radiocolloid followed by lymphoscintigraphy to identify the number and location of the primary tumor draining lymph node(s), the so-called SN(s). Over the last decade research has focused on the introduction of new imaging agents that can further aid (surgical) SN identification. Different tracers for SN mapping, with varying sizes and isotopes have been reported, most of which have proven their value in a clinical setting. A major challenge lies in transferring this diagnostic information obtained at the nuclear medicine department to the operating theatre thereby providing the surgeon with (image) guidance. Conventionally, an intraoperative injection of vital blue dye or a fluorescence dye is given to allow intraoperative optical SN identification. However, for some indications, the radiotracer-based approach remains crucial. More recently, hybrid tracers, that contain both a radioactive and fluorescent label, were introduced to allow for direct integration of pre- and intraoperative guidance technologies. Their potential is especially high when they are used in combination with new surgical imaging modalities and navigation tools. Next to a description of the known tracers for SN mapping, this review discusses the application of hybrid tracers during SN biopsy and how the introduction of these new techniques can further aid in translation of nuclear medicine information into the operating theatre.

    View details for Web of Science ID 000339308500008

    View details for PubMedID 24835293

  • A Hybrid Radioactive and Fluorescent Tracer for Sentinel Node Biopsy in Penile Carcinoma as a Potential Replacement for Blue Dye EUROPEAN UROLOGY Brouwer, O. R., van den Berg, N. S., Matheron, H. M., van der Poel, H. G., Van Rhijn, B. W., Bex, A., van Tinteren, H., Olmos, R. A., van Leeuwen, F. W., Horenblas, S. 2014; 65 (3): 600-609


    Sentinel node (SN) biopsy in penile cancer is typically performed using a combination of radiocolloid and blue dye. Recently, the hybrid radioactive and fluorescent tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was developed to combine the beneficial properties of both radio-guidance and fluorescence imaging.To explore the added value of SN biopsy using ICG-(99m)Tc-nanocolloid in patients with penile carcinoma.Sixty-five patients with penile squamous cell carcinoma were prospectively included (January 2011 to December 2012). Preoperative SN mapping was performed using lymphoscintigraphy and single-proton emission computed tomography supplemented with computed tomography (SPECT/CT) after peritumoural injection of ICG-(99m)Tc-nanocolloid. During surgery, SNs were initially approached using a gamma probe, followed by patent blue dye and/or fluorescence imaging. A portable gamma camera was used to confirm excision of all SNs.Patients underwent SN biopsy of the cN0 groin and treatment of the primary tumour.The number and location of preoperatively identified SNs were documented. Intraoperative SN identification rates using radio- and/or fluorescence guidance were assessed and compared with blue dye. Statistical evaluation was performed using a two-sample test for equality of proportions with continuity correction.Preoperative imaging after injection of ICG-(99m)Tc-nanocolloid enabled SN identification in all patients (a total of 183 SNs dispersed over 119 groins). Intraoperatively, all SNs identified by preoperative SN mapping were localised using combined radio-, fluorescence-, and blue dye guidance. Fluorescence imaging enabled visualisation of 96.8% of SNs, while only 55.7% was stained by blue dye (p<0.0001). The tissue penetration of the fluorescent signal, and the rapid flow of blue dye limited the detection sensitivity. A tumour-positive SN was found in seven patients.ICG-(99m)Tc-nanocolloid allows for both preoperative SN mapping and combined radio- and fluorescence-guided SN biopsy in penile carcinoma patients and significantly improves optical SN detection compared with blue dye.

    View details for DOI 10.1016/j.eururo.2013.11.014

    View details for Web of Science ID 000330572600023

    View details for PubMedID 24355132

  • Multimodal surgical guidance towards the sentinel node in vulvar cancer GYNECOLOGIC ONCOLOGY Matheron, H. M., van den Berg, N. S., Brouwer, O. R., KleinJan, G. H., van Driel, W. J., Trum, J. W., Vegt, E., Kenter, G., van Leeuwen, F. W., Olmos, R. A. 2013; 131 (3): 720-725


    Conventional sentinel node (SN) mapping is performed by injecting a radiocolloid followed by lymphoscintigraphy (and SPECT/CT imaging). An extra intraoperative injection with blue dye can then allow for optical identification of the SN. In order to improve the current clinical standard, the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was introduced, a tracer that is both radioactive and fluorescent. This feasibility study aimed to evaluate the value of a multimodal-based SN biopsy in vulvar cancer.Fifteen patients with vulvar cancer (29 groins) scheduled for SN biopsy were peritumorally injected with ICG-(99m)Tc-nanocolloid followed by lymphoscintigraphy and SPECT/CT imaging to identify the SNs. In thirteen patients, shortly before the start of the operation, blue dye was intradermally injected around the lesion. SNs were harvested using a combination of radiotracing, fluorescence imaging, and optical blue dye detection. A portable gamma camera was used before and after SN excision to confirm excision of the preoperatively defined SNs.Preoperative lymphoscintigraphy and SPECT/CT imaging visualized drainage to 39 SNs in 28 groins. During the operation, 98% (ex vivo 100%) of the SNs were radioactive. With fluorescence imaging 96% of the SNs (ex vivo 100%) could be visualized. Only 65% of the SNs had stained blue at the time of excision.ICG-(99m)Tc-nanocolloid can be used for preoperative SN identification and enables multimodal (radioactive and fluorescent) surgical guidance in patients with vulvar cancer. The addition of fluorescence-based optical guidance offers more effective SN visualization compared to blue dye.

    View details for DOI 10.1016/j.ygyno.2013.09.007

    View details for Web of Science ID 000327923400041

    View details for PubMedID 24051219

  • Added value of the hybrid tracer indocyanine green-99mTc-nanocolloid for sentinel node biopsy in a series of patients with different lymphatic drainage patterns. Revista espan~ola de medicina nuclear e imagen molecular Frontado, L. M., Brouwer, O. R., van den Berg, N. S., Mathéron, H. M., Vidal-Sicart, S., van Leeuwen, F. W., Valdés Olmos, R. A. 2013; 32 (4): 227-233


    Indocyanine green (ICG)-(99m)Tc-nanocolloid is a novel hybrid fluorescent radioactive tracer for sentinel node (SN) biopsy. This study has aimed to evaluate the added value of this novel versatile tracer in a series of patients with different malignancies.Twenty patients (with penile carcinoma, oral cavity tumors, melanoma) were consecutively included between March-May 2012. Planar lymphoscintigraphy was performed 15 min and 2h after injection of ICG-(99m)Tc-nanocolloid followed by SPECT/CT. Blue dye (1 ml) was injected in 14 patients in surgery room. Intraoperatively, SNs were localized using a gamma probe and visualized by optical SN-detection using blue dye and fluorescence imaging. Finally, a portable gamma camera was used to confirm complete SN removal.At least one SN was identified by SPECT/CT in all patients. All SNs (total 68, 100%) were excised using a combination of radio- and fluorescence guidance: 89.7% were intraoperatively localized with the gamma probe. The remaining SNs, located near the injection site, were localized using fluorescence imaging. During the surgery, 97% of the SNs were fluorescent while only 39.2% were stained blue. Ex vivo, all SNs were both radioactive and fluorescent. The SN was positive in 5 patients.Synchronous radio- and fluorescence guided SN biopsy is feasible using ICG-(99m)Tc-nanocolloid. This hybrid approach combines the beneficial properties of both modalities. Adding fluorescence imaging improves optical SN detection compared to blue dye. It has been shown to be especially useful in the localization of SNs near the injection site.

    View details for DOI 10.1016/j.remn.2013.02.004

    View details for PubMedID 23567320

  • Sentinel Lymph Node Biopsy for Prostate Cancer: A Hybrid Approach JOURNAL OF NUCLEAR MEDICINE van den Berg, N. S., Valdes-Olmos, R. A., van der Poel, H. G., van Leeuwen, F. W. 2013; 54 (4): 493-496


    To provide surgeons with optimal guidance during interventions, it is crucial that the molecular imaging data generated in the diagnostic departments finds its way to the operating room. Sentinel lymph node (SLN) biopsy provides a textbook example in which molecular imaging data acquired in the department of nuclear medicine guides the surgical management of patients. For prostate cancer, in which SLNs are generally located deep in the pelvis, procedures are preferably performed via a (robot-assisted) laparoscopic approach. Unfortunately, in the laparoscopic setting the senses of the surgeon are reduced. This topical review discusses technologic innovations that can help improve surgical guidance during SLN biopsy procedures.

    View details for DOI 10.2967/jnumed.112.113746

    View details for Web of Science ID 000316939200006

    View details for PubMedID 23492883

  • Metformin-an Adjunct Antineoplastic Therapy-Divergently Modulates Tumor Metabolism and Proliferation, Interfering with Early Response Prediction by F-18-FDG PET Imaging JOURNAL OF NUCLEAR MEDICINE Habibollahi, P., van den Berg, N. S., Kuruppu, D., Loda, M., Mahmood, U. 2013; 54 (2): 252-258


    Over the last several years, epidemiologic data have suggested that the antidiabetes drug metformin (MET), an adenosine monophosphate-activated protein kinase (AMPK) activator, improves progression-free survival of patients with multiple cancers; more than 30 clinical trials are under way to confirm this finding. We postulated that the role of AMPK as a central cellular energy sensor would result in opposite effects on glucose uptake and proliferation, suggesting different roles for (18)F-FDG and 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) in assessing its effectiveness as an antineoplastic agent.Colon cancer cell lines HT29 (human) and MC26 (murine) were treated for 24 or 72 h with a range of MET concentrations (0-10 mM). Western blotting was used to study the activation of AMPK after MET treatment. Glucose uptake and cell proliferation were measured by cell retention studies with either (18)F-FDG or (18)F-FLT. EdU (ethynyl deoxyuridine, a thymidine analog) and annexin-propidium iodide flow cytometry was performed to determine cell cycle S-phase and apoptotic changes. In vivo (18)F-FDG and (18)F-FLT PET images were acquired before and 24 h after MET treatment of HT29 tumor-bearing mice.After 24 h of MET incubation, phosphorylated AMPK levels increased severalfold in both cell lines, whereas total AMPK levels remained unchanged. In cell retention studies, (18)F-FDG uptake increased but (18)F-FLT retention decreased significantly in both cell lines. The numbers of HT29 and MC26 cells in the S phase decreased 36% and 33%, respectively, after MET therapy. Apoptosis increased 10.5-fold and 5.8-fold in HT29 and MC26 cells, respectively, after 72 h of incubation with MET. PET imaging revealed increased (18)F-FDG uptake (mean ± SEM standardized uptake values were 0.71 ± 0.03 before and 1.29 ± 0.11 after MET therapy) (P < 0.05) and decreased (18)F-FLT uptake (mean ± SEM standardized uptake values were 1.18 ± 0.05 before and 0.89 ± 0.01 after MET therapy) (P < 0.05) in HT29 tumor-bearing mice.MET, through activation of the AMPK pathway, produces a dose-dependent increase in tumor glucose uptake while decreasing cell proliferation in human and murine colon cancer cells. Thus, changes in (18)F-FDG uptake after MET treatment may be misleading. (18)F-FLT imaging is a promising alternative that correlates with the tumor response.

    View details for DOI 10.2967/jnumed.112.107011

    View details for Web of Science ID 000314691200026

    View details for PubMedID 23376854

  • Use of a Single Hybrid Imaging Agent for Integration of Target Validation with In Vivo and Ex Vivo Imaging of Mouse Tumor Lesions Resembling Human DCIS PLOS ONE Buckle, T., Kuil, J., van den Berg, N. S., Bunschoten, A., Lamb, H. J., Yuan, H., Josephson, L., Jonkers, J., Borowsky, A. D., van Leeuwen, F. W. 2013; 8 (1)


    Screening of biomarker expression levels in tumor biopsy samples not only provides an assessment of prognostic and predictive factors, but may also be used for selection of biomarker-specific imaging strategies. To assess the feasibility of using a biopsy specimen for a personalized selection of an imaging agent, the chemokine receptor 4 (CXCR4) was used as a reference biomarker.A hybrid CXCR4 targeting peptide (MSAP-Ac-TZ14011) containing a fluorescent dye and a chelate for radioactive labeling was used to directly compare initial flow cytometry-based target validation in fresh tumor tissue to in vivo single photon emission computed tomography (SPECT) imaging and in vivo and ex vivo fluorescence imaging.Flow cytometric analysis of mouse tumor derived cell suspensions enabled discrimination between 4T1 control tumor lesions (with low levels of CXCR4 expression) and CXCR4 positive early, intermediate and late stage MIN-O lesions based on their CXCR4 expression levels; CXCR4(basal), CXCR4(+) and CXCR4(++) cell populations could be accurately discriminated. Mean fluorescent intensity ratios between expression in MIN-O and 4T1 tissue found with flow cytometry were comparable to ratios obtained with in vivo SPECT/CT and fluorescence imaging, ex vivo fluorescence evaluation and standard immunohistochemistry.The hybrid nature of a targeting imaging agent like MSAP-Ac-TZ14011 enables integration of target selection, in vivo imaging and ex vivo validation using a single agent. The use of biopsy tissue for biomarker screening can readily be expanded to other targeting hybrid imaging agents and can possibly help increase the clinical applicability of tumor-specific imaging approaches.

    View details for DOI 10.1371/journal.pone.0048324

    View details for Web of Science ID 000314705800005

    View details for PubMedID 23326303

  • Concomitant radio- and fluorescence-guided sentinel lymph node biopsy in squamous cell carcinoma of the oral cavity using ICG-(99m)Tc-nanocolloid. European journal of nuclear medicine and molecular imaging van den Berg, N. S., Brouwer, O. R., Klop, W. M., Karakullukcu, B., Zuur, C. L., Tan, I. B., Balm, A. J., van den Brekel, M. W., Valdés Olmos, R. A., van Leeuwen, F. W. 2012; 39 (7): 1128-1136


    For oral cavity malignancies, sentinel lymph node (SLN) mapping is performed by injecting a radiocolloid around the primary tumour followed by lymphoscintigraphy. Surgically, SLNs can then be localized using a handheld gamma ray detection probe. The aim of this study was to evaluate the added value of intraoperative fluorescence imaging to the conventional radioguided procedure. For this we used indocyanine green (ICG)-(99m)Tc-nanocolloid, a hybrid tracer that is both radioactive and fluorescent.Fourteen patients with oral cavity squamous cell carcinoma were peritumourally injected with ICG-(99m)Tc-nanocolloid. SLNs were preoperatively identified with lymphoscintigraphy followed by single photon emission computed tomography (SPECT)/CT for anatomical localization. During surgery, SLNs were detected with a handheld gamma ray detection probe and a handheld near-infrared fluorescence camera. Pre-incision and post-excision imaging with a portable gamma camera was performed to confirm complete removal of all SLNs.SLNs were preoperatively identified using the radioactive signature of ICG-(99m)Tc-nanocolloid. Intraoperatively, 43 SLNs could be localized and excised with combined radio- and fluorescence guidance. Additionally, in four patients, an SLN located close to the primary injection site (in three patients this SLN was located in level I) could only be intraoperatively localized using fluorescence imaging. Pathological analysis of the SLNs revealed a metastasis in one patient.Combined preoperative SLN identification and intraoperative radio- and fluorescence guidance during SLN biopsies for oral cavity cancer proved feasible using ICG-(99m)Tc-nanocolloid. The addition of fluorescence imaging was shown to be of particular value when SLNs were located in close proximity to the primary tumour.

    View details for DOI 10.1007/s00259-012-2129-5

    View details for PubMedID 22526966

  • Fluorescence guidance in urologic surgery CURRENT OPINION IN UROLOGY van den Berg, N. S., van Leeuwen, F. W., van der Poel, H. G. 2012; 22 (2): 109-120


    Fluorescent tracers can provide anatomical and functional information without altering the visual surgical field. Despite the advances that are being made in tracer development, only a few fluorescent tracers are available for urological interventions.Protoporphyrin IX, hypericin, fluorescein, and indocyanine green were shown to facilitate surgical resection in various ways. Hybrid imaging agents, combining radio and fluorescent labels, have shown improved integration between preoperative and intraoperative imaging. With the rise of surgical fluorescence guidance, various camera systems have been developed that are tailored for optimal detection of the fluorochromes of interest.In this review, the basics of fluorescence-guided surgery, including tracer and hardware requirements are discussed.

    View details for DOI 10.1097/MOU.0b013e3283501869

    View details for Web of Science ID 000300042900005

    View details for PubMedID 22262249

  • Re: Henk G. van der Poel, Tessa Buckle, Oscar R. Brouwer, Renato A. Valdes Olmos, Fijs WB van Leeuwen. Intraoperative Laparoscopic Fluorescence Guidance to the Sentinel Lymph Node in Prostate Cancer Patients: Clinical Proof of Concept of an Integrated Functional Imaging Approach Using a Multimodal Tracer. Eur Urol 2011;60:826-33 EUROPEAN UROLOGY Polom, K., Murawa, D., Polom, W. 2012; 61 (3): E18-E18

    View details for DOI 10.1016/j.eururo.2011.12.002

    View details for Web of Science ID 000300194000006

    View details for PubMedID 22178215

  • Phosphorescence Imaging of Living Cells with Amino Acid-Functionalized Tris(2-phenylpyridine)iridium(III) Complexes INORGANIC CHEMISTRY Steunenberg, P., Ruggi, A., van den Berg, N. S., Buckle, T., Kuil, J., van Leeuwen, F. W., Velders, A. H. 2012; 51 (4): 2105-2114


    A series of nine luminescent cyclometalated octahedral iridium(III) tris(2-phenylpyridine) complexes has been synthesized, functionalized with three different amino acids (glycine, alanine, and lysine), on one, two, or all three of the phenylpyridine ligands. All starting complexes and final compounds have been fully analyzed by one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy, and photophysical data have been obtained for all the mono-, bis-, and tri- substituted iridium(III) complexes. Cellular uptake and localization have been studied with flow cytometry and confocal microscopy, respectively. Confocal experiments demonstrate that all nine substituted iridium(III) complexes show variable uptake in the tumor cells. The monosubstituted iridium(III) complexes give the highest cellular uptake, and the series substituted with lysines shows the highest toxicity. This systematic study of amino acid-functionalized Ir(ppy)(3) complexes provides guidelines for further functionalization and possible implementation of luminescent iridium complexes, for example, in (automated) peptide synthesis or biomarker specific targeting.

    View details for DOI 10.1021/ic201860s

    View details for Web of Science ID 000300466300019

    View details for PubMedID 22303934

  • Non-invasive longitudinal imaging of tumor progression using an 111Indium labeled CXCR4 peptide antagonist Buckle, T., van den Berg, N. S., Kuil, J., Bunschoten, A., Oldenburg, J., Borowsky, A. D., Wesseling, J., MASADA, R., Oishi, S., Fujii, N., van Leeuwen, F. W. SPRINGER. 2011: S145–S145
  • Immunohistochemical detection of the CXCR4 expression in tumor tissue using the fluorescent peptide antagonist Ac-TZ14011-FITC. Translational oncology van den Berg, N. S., Buckle, T., Kuil, J., Wesseling, J., van Leeuwen, F. W. 2011; 4 (4): 234-240


    Pathology is fundamental in grading, staging, and treatment planning of malignancies. One relatively novel biomarker that may become more important in therapy and diagnostics is the chemokine receptor 4 (CXCR4). Ac-TZ14011 peptide derivatives, functionalized with a radiolabel, can be used for molecular imaging of tumors. Direct fluorescent labeling of the small peptide Ac-TZ14011 with the fluorescent dye fluorescein isothiocyanate (FITC), however, provides an alternative for the detection of CXCR4 expression levels in cells and tumor tissue. In this study, Ac-TZ14011-FITC was validated for CXCR4 staining in human breast cancer cell lines MDAMB231 and MDAMB231(CXCR4+) during flow cytometric analysis. Its efficacy was compared to commercially available antibodies. Competition experiments validated the staining specificity. Confocal imaging revealed that CXCR4 staining was predominantly found on the cell membrane and/or in vesicles formed after endocytosis. Next to being able to differentiate "high" and "low" CXCR4-expressing tumor cells, the fluorescent peptide demonstrates potential in fluorescent immunohistochemistry of tumor tissue. Ac-TZ14011-FITC was able to differentiate MDAMB231 from MDAMB231(CXCR4+) tumor cells and tissue, proving its applicability in the detection of differences in CXCR4 expression levels.

    View details for PubMedID 21804919

  • Synthesis and Evaluation of a Bimodal CXCR4 Antagonistic Peptide BIOCONJUGATE CHEMISTRY Kuil, J., Buckle, T., Yuan, H., van den Berg, N. S., Oishi, S., Fujii, N., Josephson, L., van Leeuwen, F. W. 2011; 22 (5): 859-864


    The antagonistic Ac-TZ14011 peptide, which binds to the chemokine receptor 4, has been labeled with a multifunctional single attachment point reagent that contains a DTPA chelate and a fluorescent dye with Cy5.5 spectral properties. Flow cytometry and confocal microscopy showed that the bimodal labeled peptide gave a specific receptor binding that is similar to monofunctionalized peptide derivatives. Therefore, the newly developed bimodal peptide derivative can be used in multimodal imaging applications.

    View details for DOI 10.1021/bc2000947

    View details for Web of Science ID 000290691600002

    View details for PubMedID 21480671

  • Tumor bracketing and safety margin estimation using multimodal marker seeds: a proof of concept JOURNAL OF BIOMEDICAL OPTICS Buckle, T., Chin, P. T., van den Berg, N. S., Loo, C. E., Koops, W., Gilhuijs, K. G., van Leeuwen, F. W. 2010; 15 (5)


    Accurate tumor excision is crucial in the locoregional treatment of cancer, and for this purpose, surgeons often rely on guide wires or radioactive markers for guidance toward the lesion. Further improvement may be obtained by adding optical guidance to currently used methods, in the form of intra-operative fluorescence imaging. To achieve such a multimodal approach, we have generated markers that can be used in a pre-, intra-, and post-operative setting, based on a cocktail of a dual-emissive inorganic dye, lipids, and pertechnetate. Phantom experiments demonstrate that these seeds can be placed accurately around a surrogate tumor using ultrasound. Three-dimensional bracketing provides delineation of the entire lesion. Combined with the multimodal nature, this provides the opportunity to predetermine the resection margins by validating the placement accuracy using multiple imaging modalities (namely, x ray, MRI, SPECT/CT, and ultrasound). The dual-emissive fluorescent properties of the dye provide the unique opportunity to intra-operatively estimate the depth of the seed in the tissue via multispectral imaging: emission green λmax=520 nm≤5 mm penetration versus emission red λmax=660 nm≤12 mm penetration. By using particles with different colors, the original geographic orientation of the excised tissue can be determined.

    View details for DOI 10.1117/1.3503955

    View details for Web of Science ID 000284837400043

    View details for PubMedID 21054115