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 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.

Education

  • 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. Lichter KE, Asaro A, Qureshi MM, Truong MT, Parekh A, Witztum A, Anand C, Silva GS, Royce T, Zaorsky NG, Grover S, Abdel-Wahab M, Thiel C, Eckelman MJ, Prionas N, Yom SS, Mohamad O The climate and health impact of U.S. radiation therapy: estimating greenhouse gas emissions, DALYs, and potential of hypofractionation.  View on PubMed
  2. Van Hassel J, Dimitroff K, Yau C, Mukhtar R, Boughey JC, Ladores V, Howard-McNatt MM, Jaskowiak N, Perlmutter J, DeMichele A, Yee D, Hylton N, Symmans WF, Veer LV, Rugo H, Esserman LJ, Shatsky R, Isaacs C, Kuerer H, Wallace AM, Prionas N, Tseng J, Reyna CR, Taunk N, Kesmodel S, Lee MC, Fox J, Piltin MA, Tchou J, Arciero CA, Postlewait LM, Sauder C, Rao R Impact of Time to Surgery Post Neoadjuvant Chemotherapy on Breast Cancer Outcomes: A Retrospective Study of Patients Enrolled in the I-SPY 2 Clinical Trial.  View on PubMed
  3. Mukhtar RA, Dimitroff K, Yau C, Chien AJ, Connolly EP, Howard-McNatt M, Rao R, Ladores V, Golshan M, Sauder CA, Ahmed K, Lancaster R, Fox J, Gutnik L, Lee MC, Tchou J, Prionas N, Arciero CA, Reyna C, Kuerer H, Switalla K, Taunk N, Tuttle TM, Moran MS, Postlewait LM, Perlmutter J, DeMichele A, Yee D, Hylton N, Symmans WF, Rugo HS, Shatsky R, Isaacs C, Esserman LJ, Van't Veer L, Boughey JC Impact of Neoadjuvant Chemotherapy on Surgical Outcomes and Conversion to Node-Negativity in Invasive Lobular Breast Cancer: Analysis of Molecularly High-Risk Tumors by Histologic Subtype on the I-SPY2 Clinical Trial.  View on PubMed
  4. Kaur M, Dimitroff K, Boughey JC, Esserman LJ, Yau C, Tchou J, Quirarte A, Lee MC, Howard-McNatt MM, Switalla K, Kuerer H, Sauder C, Postlewait LM, Arciero C, Rao R, Wallace A, Reyna C, Ahmed K, Gutnik L, Taunk N, Perlmutter J, DeMichele A, Yee D, Hylton NM, Symmans WF, Rugo HS, Shatsky RA, Isaacs C, Rudra S, Pohlmann P, Ewing C, Wong J, Alvarado M, Jaskowiak N, Prionas N, Golshan M, Piltin MA, Olopade OI, Mukhtar RA Disparities in the Surgical Management of the Axilla by Self-Identified Race in the Multicenter Neoadjuvant I-SPY2 Trial.  View on PubMed
  5. Baniel CC, Lichter KE, Frick MA, Wu J, Oladipo E, Wu YF, SwamyS A, Hsu IC, Prionas N, Blomain ES, Kidd EA, Buyyounouski MK, Rosenbluth G, Mohamad O, Bagshaw HP. The NorCal brachytherapy waste audit: A simple, validated, toolkit for clinician led waste reduction. Brachytherapy. 2025 Mar 01.  View on PubMed
  6. Spiegel DY, Friesner ID, Zhang W, Zack T, Yan G, Willcox J, Prionas N, Singer L, Park C, Hong JC. Exploring the Social Media Discussion of Breast Cancer Treatment Choices: Quantitative Natural Language Processing Study. JMIR Cancer. 2025 Jan 28; 11:e52886.  View on PubMed
  7. Chen JJ, Zhu I, Patel A, Krings G, Chen YY, Yuen F, Mukhtar RA, Melisko M, Singer L, Park CC, Prionas ND. Management of Concurrent Malignant Phyllodes Tumor and Invasive Breast Carcinoma. Adv Radiat Oncol. 2024 May; 9(5):101448.  View on PubMed
  8. Capaldi DPI, Axente M, Yu AS, Prionas ND, Hirata E, Nano TF. A Couch Mounted Smartphone-based Motion Monitoring System for Radiation Therapy. Pract Radiat Oncol. 2024 Mar-Apr; 14(2):161-170.  View on PubMed
  9. Barnes LL, Chew J, Lem M, Park C, Yang JC, Prionas N, Piper M. Modifiable Postmastectomy Radiation Therapy Factors and Impact on Implant-Based Breast Reconstruction Outcomes. Plast Reconstr Surg. 2024 May 01; 153(5):1000-1009.  View on PubMed
  10. Prionas ND, Park CC. Contralateral Disease Begets Contralateral Treatment. Int J Radiat Oncol Biol Phys. 2022 07 01; 113(3):490.  View on PubMed
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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

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