Research Summary

Spencer Behr, MD, is an Assistant Professor of Clinical Radiology and the Director of the Fellowship for both the Abdominal Imaging subspecialty and for the Department of Radiology and Biomedical Imaging at the University of California, San Francisco. He obtained his medical degree from Tufts University School of Medicine, Boston in 2005. In 2010, he completed a four-year Diagnostic Radiology residency at the Lahey Clinic Medical Center in Burlington, Massachusetts, followed by a fellowship in Abdominal Imaging and Nuclear Medicine at UCSF.

Dr. Behr has subspecialty training in abdominal imaging and nuclear medicine, and his research interests are focused on molecular and hybrid imaging translational research. He has selectively pursued interdepartmental projects to foster cross-disciplinary discussions and optimize the clinical impact of these projects.

Projects include: FDG PET in breast cancer, comparing breast cancer molecular subtypes with their respective FDG PET and breast MRI findings, CT findings in Celiac Disease, fluoro-18-fluorothymidine (FLT) PET as a potential marker of early response in patients with metastatic melanoma, CT appearance of malabsorption, and clinical applications of iodine-124 PET/CT in thyroid cancer.

Education

Massachusetts Institute of Technology, BS, 06/1999, Biology and Chemistry
Tufts University School of Medicine, Boston, MA, MD, 06/2005, Medicine
Saint Vincent Hospital, Worchester, MA, Intern, 06/2006, Medicine
Lahey Clinic Medical Center, Burlington, MA, Resident & Chief Resident, 06/2010, Diagnostic Radiology
University of California, San Francisco, San Francisco, CA, Fellow, 06/2011, Abdominal Imaging
University of California, San Francisco, San Francisco, CA, Fellow, 06/2012, Nuclear Medicine

Honors & Awards

  • 2015
    Nominated for "Radiology Award for Outstanding Faculty Mentoring", UCSF
  • 2017
    Hideyo Minagi "Outstanding Teacher Award", UCSF
  • 2017
    Radiological Society of North America (RSNA) Honored Educator Award Recipient, Radiological Society of North America (RSNA)
  • 2017
    2017 Excellence in Teaching Award, Academy of Medical Educators at UCSF

Selected Publications

  1. Taya M, Aschauer T, Villanueva-Meyer J, Kolli KP, Yeh BM, Behr SC. Abdominal Imaging Interpretive Errors in a Quality Assurance Database: One Institution's Experience Over a 5-Year Period. J Comput Assist Tomogr. 2026 Mar 02. View on PubMed
  2. Strosberg JR, Zemla T, Geyer S, Pulsipher S, Ou FS, Behr S, Raj N, Vijayvergia N, Dasari A, O'Reilly EM, Meyerhardt JA, Wolin EM, Halfdanarson TR, Chan JA. Cabozantinib for advanced grade 3 neuroendocrine tumors: subgroup analysis of the phase 3 CABINET trial (Alliance A021602). Endocr Relat Cancer. 2026 Jan 01; 33(1). View on PubMed
  3. Firoozeh N, Mastrodicasa D, Behr S, Muglia VF, Westphalen AC. Zero-Shot PI-RADS Version 2.1 Scoring with ChatGPT-4 Turbo and Llama 3: Diagnostic Performance and Agreement with Abdominal Radiologists. Radiol Imaging Cancer. 2026 Jan; 8(1):e250119. View on PubMed
  4. Bergsland EK, Geyer S, Asmis TR, Behr SC, Kuebler JP, Kumthekar P, Mazza G, Maitland ML, Niedzwiecki D, Nixon AB, Schwartz LH, Strosberg JR, Venook AP, O'Reilly EM, Meyerhardt JA. Randomized Phase II Trial of Pazopanib Versus Placebo in Patients With Advanced Extrapancreatic Neuroendocrine Tumors (Alliance A021202). J Clin Oncol. 2025 Oct 10; 43(29):3170-3183. View on PubMed
  5. Iagaru A, Suarez JF, Behr S, Aggarwal R, Paredes P, Buffi N, Penhoat T, Ceci F, Walz J, Doumerc N, Coulanges M, Xu Z, Seigne C, Wilke C, Catafau AM, Fanti S, Maurer T, GuideView study investigators. Imaging Efficacy of [18F]CTT1057 PET for the Detection of PSMA-Positive Tumors Using Histopathology as Standard of Truth: Results from the GuideView Phase 2/3 Prospective Multicenter Study. J Nucl Med. 2025 Aug 01; 66(8):1232-1238. View on PubMed
  6. Fanti S, Robles Barba JJ, Behr S, Maurer T, Paredes P, Walz J, Duch J, Perdigo MS, Mainta IC, Bonnefoy PB, Coulanges M, Tang J, Seigne C, Wilke C, Catafau AM, Iagaru A, Aggarwal R. Imaging Efficacy of [18F]CTT1057 PET/CT in Patients with Biochemically Recurrent Prostate Cancer: Results from GuidePath-A Phase 3, Prospective Multicenter Study. J Nucl Med. 2025 Aug 01; 66(8):1210-1216. View on PubMed
  7. Firoozeh N, Behr SC, Westphalen AC. Predicting uninformative prostate magnetic resonance imaging sequences: a hypothesis-generating pilot study. Radiol Bras. 2025 Jan-Dec; 58:e20250007. View on PubMed
  8. Kirsch A, Strachowski L, Poder L, Behr S, Feldstein V, Harwin J, Lehrman E, Rabban J, Shum D, Whetstone S, Choi H. Secondary Postpregnancy Hemorrhage: Guide for Diagnosis and Management. Radiographics. 2025 05; 45(5):e240098. View on PubMed
  9. Hong CW, Behr SC, Jiang F, Wang Y, Houshmand S, Hope TA. Added Value of Whole-Body Diffusion-Weighted Imaging in Patients Undergoing Prostate-Specific Membrane Antigen Positron Emission Tomography. J Clin Med. 2025 Mar 08; 14(6). View on PubMed
  10. Chan JA, Geyer S, Zemla T, Knopp MV, Behr S, Pulsipher S, Ou FS, Dueck AC, Acoba J, Shergill A, Wolin EM, Halfdanarson TR, Konda B, Trikalinos NA, Tawfik B, Raj N, Shaheen S, Vijayvergia N, Dasari A, Strosberg JR, Kohn EC, Kulke MH, O'Reilly EM, Meyerhardt JA. Phase 3 Trial of Cabozantinib to Treat Advanced Neuroendocrine Tumors. N Engl J Med. 2025 Feb 13; 392(7):653-665. View on PubMed
  11. Bhattacharjee R, Hammond E, Chotigar N, Akkaya Z, Jiang F, Bahroos E, Han M, Behr S, Bucknor MD, Souza RB, Pedoia V, Majumdar S. The relationships between patellofemoral bone remodeling, cartilage composition, and vertical loading rate: PET/MRI in isolated patellofemoral osteoarthritis. Osteoarthritis Cartilage. 2024 Dec; 32(12):1591-1600. View on PubMed
  12. Awali M, El Homsi M, Fraum TJ, Shetty AS, Ponisio MR, Gharzeddine K, Mhlanga J, Mallak N, Behr S, Itani M. PET/MRI: pictorial review of hepatobiliary and pancreatic applications. Abdom Radiol (NY). 2025 02; 50(2):875-901. View on PubMed
  13. Wang J, Ashraf Ganjouei A, Romero-Hernandez F, Foroutani L, Bahceci D, Deranteriassian A, Casey M, Li PY, Houshmand S, Behr S, Jamshidi N, Majumdar S, Donahue T, Kim GE, Wang ZJ, Thornblade LW, Adam M, Alseidi A. A Computer Vision Algorithm to Predict Superior Mesenteric Artery Margin Status for Patients With Pancreatic Ductal Adenocarcinoma. Ann Surg. 2026 May 01; 283(5):834-840. View on PubMed
  14. Diwanji D, Carrodeguas E, Seo Y, Kang H, Soe MH, Chiang JM, Zhang L, Liu C, Behr SC, Flavell RR. Comparative Uptake Patterns of Radioactive Iodine and [18F]-Fluorodeoxyglucose (FDG) in Metastatic Differentiated Thyroid Cancers. J Clin Med. 2024 Jul 06; 13(13). View on PubMed
  15. Taya M, Behr SC, Westphalen AC. Perspectives on technology: Prostate Imaging-Reporting and Data System (PI-RADS) interobserver variability. BJU Int. 2024 10; 134(4):510-518. View on PubMed
  16. Kline B, Yadav S, Seo Y, Ippisch RC, Castillo J, Aggarwal RR, Kelley RK, Behr SC, Flavell RR, Lawhn-Heath C, Melisko M, Rugo HS, Wang V, Yom SS, Ha P, Jiang F, Hope TA. 68Ga-FAP-2286 PET of Solid Tumors: Biodistribution, Dosimetry, and Comparison with 18F-FDG. J Nucl Med. 2024 06 03; 65(6):938-943. View on PubMed
  17. Mar D, Diwanji D, Lowery B, Zhang L, Hope TA, Behr SC, Flavell RR. Pathologic outcome of incidentally detected tracer-avid lesions in 68Ga-PSMA-11 PET/CT for prostate cancer. Radiol Adv. 2024 May; 1(1):umae008. View on PubMed
  18. Hassan OT, Behr SC, Ohliger MA, Fowler KJ, Gill RM, Fidelman N, Mehta N, Choi HH. Per-patient Negative Predictive Value of the CT and MRI Liver Imaging Reporting and Data System Version 2018 Treatment Response Algorithm for Hepatocellular Carcinoma. Radiology. 2023 12; 309(3):e222776. View on PubMed
  19. Houshmand S, Lawhn-Heath C, Behr S. PSMA PET imaging in the diagnosis and management of prostate cancer. Abdom Radiol (NY). 2023 12; 48(12):3610-3623. View on PubMed
  20. Wang SJ, Whitman J, Paciorek A, Le BK, Nakakura EK, Behr SC, Joseph N, Zhang L, Hope TA, Bergsland EK. Baseline tumor growth rate highlights the heterogeneity of well differentiated gastroenteropancreatic neuroendocrine tumors and predicts for increases in Ki67 index over time. J Neuroendocrinol. 2023 04; 35(4):e13260. View on PubMed

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