Education & Certifications

  • Bachelor of Arts, Brown University (2016)

All Publications

  • Radiopaque Recreations of Lung Pathologies From Clinical Computed Tomography Images Using Potassium Iodide Inkjet 3-dimensional Printing: Proof of Concept. Journal of thoracic imaging Wang, J., Falkson, S. R., Guo, H. H. 2021


    PURPOSE: The purpose of this study was to develop a 3-dimensional (3D) printing method to create computed tomography (CT) realistic phantoms of lung cancer nodules and lung parenchymal disease from clinical CT images.MATERIALS AND METHODS: Low-density paper was used as substrate material for inkjet printing with potassium iodide solution to reproduce phantoms that mimic the CT attenuation of lung parenchyma. The relationship between grayscale values and the corresponding CT numbers of prints was first established through the derivation of exponential fitted equation from scanning data. Next, chest CTs from patients with early-stage lung cancer and coronavirus disease 2019 (COVID-19) pneumonia were chosen for 3D printing. CT images of original lung nodule and the 3D-printed nodule phantom were compared based on pixel-to-pixel correlation and radiomic features.RESULTS: CT images of part-solid lung cancer and 3D-printed nodule phantom showed both high visual similarity and quantitative correlation. R2 values from linear regressions of pixel-to-pixel correlations between 5 sets of patient and 3D-printed image pairs were 0.92, 0.94, 0.86, 0.85, and 0.83, respectively. Comparison of radiomic measures between clinical CT and printed models demonstrated 6.1% median difference, with 25th and 75th percentile range at 2.4% and 15.2% absolute difference, respectively. The densities and parenchymal morphologies from COVID-19 pneumonia CT images were well reproduced in the 3D-printed phantom scans.CONCLUSION: The 3D printing method presented in this work facilitates creation of CT-realistic reproductions of lung cancer and parenchymal disease from individual patient scans with microbiological and pathology confirmation.

    View details for DOI 10.1097/RTI.0000000000000607

    View details for PubMedID 34334783

  • Hepatocellular Carcinoma Brain Metastases: A Single-Institution Experience. World neurosurgery Falkson, S. R., Bhambhvani, H. P., Gephart, M. H. 2020


    BACKGROUND: Brain metastases (BM) from hepatocellular carcinoma (HCC) are rare, with a paucity of published cases. In this retrospective cohort report, we assess the proportion of BM arising from HCC and characterize related details including patient demography, clinical characteristics, treatment modalities, and survival outcomes.METHODS: We retrospectively identified and reviewed the charts of 14 patients with BM from HCC seen at our institution from 2008 to 2018.RESULTS: Among all patients with BM, the proportion originating from primary liver cancer was 0.39%. In every instance (14), the liver cancer was HCC. Median age at the time of BM diagnosis was 64 (range, 37-82). Median alpha-fetoprotein (AFP) at the time of BM was 540 ng/mL (range, 3-10,000). The median time from HCC diagnosis to BM was 31.1 months (range, 3.17-107). 8 of the 14 patients (57%) had metastases to brain parenchyma, while the remaining 6 had skull/dural metastases. For patients with brain parenchymal metastases, the median number of metastases was 1 (range, 1-5). 13 of the 14 patients are deceased, with median overall survival post BM diagnosis of 2.83 months (range, 0.430-24.0). The surviving patient is 142 months post BM diagnosis. Resection of the BM with radiosurgery was associated with increased survival as compared to radiosurgery alone (10.9 months versus 2.8 months, p=0.04).CONCLUSIONS: HCC BM is rare and constitutes a small fraction of total BM. The prognostic data provided in this report can aid medical providers in caring for patients with HCC BM.

    View details for DOI 10.1016/j.wneu.2020.03.189

    View details for PubMedID 32289508

  • Clinical characteristics associated with COVID-19 severity in California. Journal of clinical and translational science Rubin, S. J., Falkson, S. R., Degner, N. R., Blish, C. 2020; 5 (1): e3


    Given the rapidly progressing coronavirus disease 2019 (COVID-19) pandemic, this report on a US cohort of 54 COVID-19 patients from Stanford Hospital and data regarding risk factors for severe disease obtained at initial clinical presentation is highly important and immediately clinically relevant. We identified low presenting oxygen saturation as predictive of severe disease outcomes, such as diagnosis of pneumonia, acute respiratory distress syndrome, and admission to the intensive care unit, and also replicated data from China suggesting an association between hypertension and disease severity. Clinicians will benefit by tools to rapidly risk stratify patients at presentation by likelihood of progression to severe disease.

    View details for DOI 10.1017/cts.2020.40

    View details for PubMedID 34192044

    View details for PubMedCentralID PMC7274026

  • Safety of ACE-I and ARB medications in COVID-19: A retrospective cohort study of inpatients and outpatients in California Journal of Clinical and Translational Science Rubin, S. J., Falkson, S. R., Degner, N. R., Blish, C. A. 2020: e8


    There is significant interest in the use of angiotensin converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARB) in coronavirus disease 2019 (COVID-19) and concern over potential adverse effects since these medications upregulate the severe acute respiratory syndrome coronavirus 2 host cell entry receptor ACE2. Recent studies on ACE-I and ARB in COVID-19 were limited by excluding outpatients, excluding patients by age, analyzing ACE-I and ARB together, imputing missing data, and/or diagnosing COVID-19 by chest computed tomography without definitive reverse transcription polymerase chain reaction (RT-PCR), all of which are addressed here.We performed a retrospective cohort study of 1023 COVID-19 patients diagnosed by RT-PCR at Stanford Hospital through April 8, 2020 with a minimum follow-up time of 14 days to investigate the association between ACE-I or ARB use with outcomes.Use of ACE-I or ARB medications was not associated with increased risk of hospitalization, intensive care unit admission, or death. Compared to patients with charted past medical history, there was a lower risk of hospitalization for patients on ACE-I (odds ratio (OR) 0.43; 95% confidence interval (CI) 0.19-0.97; P = 0.0426) and ARB (OR 0.39; 95% CI 0.17-0.90; P = 0.0270). Compared to patients with hypertension not on ACE-I or ARB, patients on ARB medications had a lower risk of hospitalization (OR 0.09; 95% CI 0.01-0.88; P = 0.0381).These findings suggest that the use of ACE-I and ARB is not associated with adverse outcomes and may be associated with improved outcomes in COVID-19, which is immediately relevant to care of the many patients on these medications.

    View details for DOI 10.1017/cts.2020.489

    View details for PubMedCentralID PMC7605244