Research Summary

Dr. Nicolas Prionas, M.D. Ph.D., is a radiation oncologist with clinical expertise and interest in the detection, diagnosis, and management of breast cancer. As a native of the San Francisco Bay Area, he is passionate about bringing UCSF care into the community across the entire region. He treats people with malignancies of all disease sites and has expertise in specialized procedures including intensity modulated radiotherapy (IMRT), stereotactic ablative/body radiotherapy (SABR/SBRT), stereotactic radiosurgery (SRS), image-guided radiotherapy (IGRT), and intra-operative radiotherapy (IORT).

Dr. Prionas received a B.S. in Biomedical Computation and a M.S. in Biomechanical Engineering from Stanford University. He completed joint MD/PhD training in Biomedical Engineering at the University of California, Davis School of Medicine where his research specialized in quantitative imaging and radiotherapy using a novel dedicated breast computed tomography platform. Prior to arriving at UCSF, he completed Radiation Oncology Residency training at Stanford University where he was awarded the Malcolm A. Bagshaw Award for leadership and outstanding scientific achievement. Dr. Prionas is the Director of Quality and his research focuses on technologies that increase access to equitable care.


  • Stanford University, B.S. 2005, Biomedical Computation
  • Stanford University, M.S., 2006, Biomechanical Engineering
  • University of California, Davis, Ph.D., 2012, Biomedical Engineering
  • University of California, Davis, M.D., 2014, Medicine
  • Santa Clara Valley Medical Center, Internship, 2015
  • Stanford University, Residency, 2019

Honors & Awards

  • 2019
    Malcolm A. Bagshaw Award, Stanford Radiation Oncology
  • 2018
    NCCN Oncology Fellows Program Grant, National Comprehensive Cancer Network
  • 2015
    Transitional Intern of the Year, Santa Clara Valley Medical Center
  • 2014
    Northern California Regional Meeting First Place Clinical Vignette Poster, American College of Physicians
  • 2014
    J.T. “Simon” Lie Memorial Scholarship for Achievement in Superior Academics and Involvement in Public Service and Leadership, University of California, Davis School of Medicine
  • 2014
    Russel A. McFall, MD Excellence in Radiology, University of California, Davis School of Medicine
  • 2014
    Phi Kappa Phi Honor Society, University of California, Davis School of Medicine
  • 2013
    Alpha Omega Alpha Honor Medical Society, Junior inductee, University of California, Davis School of Medicine
  • 2012
    Gale Hansen Starich, PhD, Oral Presentation Award, Western Student Medical Research Forum
  • 2011
    Golden Key International Honour Society

Selected Publications

  1. Barnes LL, Chew J, Lem M, Park C, Yang JC, Prionas N, Piper M. Modifiable Post-Mastectomy Radiation Therapy Factors and Impact on Implant-Based Breast Reconstruction Outcomes. Plast Reconstr Surg. 2023 Jun 19.  View on PubMed
  2. Prionas ND, Park CC. Contralateral Disease Begets Contralateral Treatment. Int J Radiat Oncol Biol Phys. 2022 07 01; 113(3):490.  View on PubMed
  3. Prionas ND, Stephens SJ, Blitzblau RC. Early-stage Breast Cancer: Tailored External Beam Fractionation Approaches for Treatment of the Whole or Partial Breast. Semin Radiat Oncol. 2022 07; 32(3):245-253.  View on PubMed
  4. Hewitt KC, Miller P, Piper M, Prionas N, Son JD, Alvarado M, Esserman LJ, Wong JM, Ewing C, Mukhtar RA. Positive margins after mastectomy in patients with invasive lobular carcinoma of the breast: Incidence and management strategies. Am J Surg. 2022 04; 223(4):699-704.  View on PubMed
  5. Prionas ND, Kung TH, Dohn A, Piro N, von Eyben R, Katznelson L, Caruso TJ. A pilot, randomized controlled trial of telementorship: A useful tool during social distancing. J Clin Transl Res. 2021 Feb 25; 7(1):66-71.  View on PubMed
  6. Levin-Epstein RG, Jiang NY, Wang X, Upadhyaya SK, Collins SP, Suy S, Aghdam N, Mantz C, Katz AJ, Miszczyk L, Napieralska A, Namysl-Kaletka A, Prionas N, Bagshaw H, Buyyounouski MK, Cao M, Agazaryan N, Dang A, Yuan Y, Kupelian PA, Zaorsky NG, Spratt DE, Mohamad O, Feng FY, Mahal BA, Boutros PC, Kishan AU, Juarez J, Shabsovich D, Jiang T, Kahlon S, Patel A, Patel J, Nickols NG, Steinberg ML, Fuller DB, Kishan AU. Dose-response with stereotactic body radiotherapy for prostate cancer: A multi-institutional analysis of prostate-specific antigen kinetics and biochemical control. Radiother Oncol. 2021 01; 154:207-213.  View on PubMed
  7. Gutkin PM, Prionas ND, Minneci MO, Allen E, Balazy KE, Rahimy E, Chang DT, Horst KC. Telemedicine in Radiation Oncology: Is It Here to Stay? Impacts on Patient Care and Resident Education. Int J Radiat Oncol Biol Phys. 2020 Oct 01; 108(2):416-420.  View on PubMed
  8. Skinner LB, Niedermayr T, Prionas N, Perl J, Fahimian B, Kidd EA. Intensity modulated Ir-192 brachytherapy using high-Z 3D printed applicators. Phys Med Biol. 2020 07 31; 65(15):155018.  View on PubMed
  9. Levin-Epstein R, Cook RR, Wong JK, Stock RG, Jeffrey Demanes D, Collins SP, Aghdam N, Suy S, Mantz C, Katz AJ, Nickols NG, Miszczyk L, Napieralska A, Namysl-Kaletka A, Prionas ND, Bagshaw H, Buyyounouski MK, Cao M, Mahal BA, Shabsovich D, Dang A, Yuan Y, Rettig MB, Chang AJ, Jackson WC, Spratt DE, Lehrer EJ, Zaorsky NG, Kupelian PA, Steinberg ML, Horwitz EM, Jiang NY, Kishan AU. Prostate-specific antigen kinetics and biochemical control following stereotactic body radiation therapy, high dose rate brachytherapy, and low dose rate brachytherapy: A multi-institutional analysis of 3502 patients. Radiother Oncol. 2020 10; 151:26-32.  View on PubMed
  10. Benson KRK, Aggarwal S, Carter JN, von Eyben R, Pradhan P, Prionas ND, Bui JL, Soltys SG, Hancock S, Gensheimer MF, Koong AC, Chang DT. Predicting Survival for Patients With Metastatic Disease. Int J Radiat Oncol Biol Phys. 2020 01 01; 106(1):52-60.  View on PubMed
  11. Jiang NY, Dang AT, Yuan Y, Chu FI, Shabsovich D, King CR, Collins SP, Aghdam N, Suy S, Mantz CA, Miszczyk L, Napieralska A, Namysl-Kaletka A, Bagshaw H, Prionas N, Buyyounouski MK, Jackson WC, Spratt DE, Nickols NG, Steinberg ML, Kupelian PA, Kishan AU. Multi-Institutional Analysis of Prostate-Specific Antigen Kinetics After Stereotactic Body Radiation Therapy. Int J Radiat Oncol Biol Phys. 2019 11 01; 105(3):628-636.  View on PubMed
  12. Kishan AU, Dang A, Katz AJ, Mantz CA, Collins SP, Aghdam N, Chu FI, Kaplan ID, Appelbaum L, Fuller DB, Meier RM, Loblaw DA, Cheung P, Pham HT, Shaverdian N, Jiang N, Yuan Y, Bagshaw H, Prionas N, Buyyounouski MK, Spratt DE, Linson PW, Hong RL, Nickols NG, Steinberg ML, Kupelian PA, King CR. Long-term Outcomes of Stereotactic Body Radiotherapy for Low-Risk and Intermediate-Risk Prostate Cancer. JAMA Netw Open. 2019 02 01; 2(2):e188006.  View on PubMed
  13. Prionas ND, von Eyben R, Yi E, Aggarwal S, Shaffer J, Bazan J, Eastham D, Maxim PG, Graves EE, Diehn M, Gensheimer MF, Loo BW. Increases in Serial Pretreatment 18F-FDG PET-CT Metrics Predict Survival in Early Stage Non-Small Cell Lung Cancer Treated With Stereotactic Ablative Radiation Therapy. Adv Radiat Oncol. 2019 Apr-Jun; 4(2):429-437.  View on PubMed
  14. Qian Y, Von Eyben R, Liu Y, Chin FT, Miao Z, Apte S, Carter JN, Binkley MS, Pollom EL, Harris JP, Prionas ND, Kissel M, Simmons A, Diehn M, Shultz DB, Brown JM, Maxim PG, Koong AC, Graves EE, Loo BW. 18F-EF5 PET-based Imageable Hypoxia Predicts Local Recurrence in Tumors Treated With Highly Conformal Radiation Therapy. Int J Radiat Oncol Biol Phys. 2018 11 15; 102(4):1183-1192.  View on PubMed
  15. Kishan AU, Wang PC, Upadhyaya SK, Hauswald H, Demanes DJ, Nickols NG, Kamrava M, Sadeghi A, Kupelian PA, Steinberg ML, Prionas ND, Buyyounouski MK, King CR. SBRT and HDR brachytherapy produce lower PSA nadirs and different PSA decay patterns than conventionally fractionated IMRT in patients with low- or intermediate-risk prostate cancer. Pract Radiat Oncol. 2016 Jul-Aug; 6(4):268-275.  View on PubMed
  16. Aminololama-Shakeri S, Abbey CK, Gazi P, Prionas ND, Nosratieh A, Li CS, Boone JM, Lindfors KK. Differentiation of ductal carcinoma in-situ from benign micro-calcifications by dedicated breast computed tomography. Eur J Radiol. 2016 Jan; 85(1):297-303.  View on PubMed
  17. Prionas ND, Burkett GW, McKenney SE, Chen L, Stern RL, Boone JM. Development of a patient-specific two-compartment anthropomorphic breast phantom. Phys Med Biol. 2012 Jul 07; 57(13):4293-307.  View on PubMed
  18. Prionas ND, McKenney SE, Stern RL, Boone JM. Kilovoltage rotational external beam radiotherapy on a breast computed tomography platform: a feasibility study. Int J Radiat Oncol Biol Phys. 2012 Oct 01; 84(2):533-9.  View on PubMed
  19. Katzberg RW, Monsky WL, Prionas ND, Sidhar V, Southard J, Carlson J, Boone JM, Lin TC, Li CS. Persistent CT nephrograms following cardiac catheterisation and intervention: initial observations. Insights Imaging. 2012 Feb; 3(1):49-60.  View on PubMed
  20. Huang SY, Boone JM, Yang K, Packard NJ, McKenney SE, Prionas ND, Lindfors KK, Yaffe MJ. The characterization of breast anatomical metrics using dedicated breast CT. Med Phys. 2011 Apr; 38(4):2180-91.  View on PubMed

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