University of California San Francisco
Helen Diller Family Comprehensive Cancer Center
Bruce Faddegon, PhD

Bruce Faddegon, PhD

Professor in Residence, Department of Radiation Oncology, UCSF

Cancer Center Program Memberships


Research Summary

Dr. Faddegon is a board certified clinical medical physics who is internationally recognized for his research in developing and using Monte Carlo methods for treatment head simulation and dose calculation with an eye to improving accuracy and precision in radiotherapy. The overall objective of Dr. Faddegon’s research is to allow for more aggressive treatment in sites where side effects, local control, and even metastases are a problem through cost-effective solutions to improve the therapeutic ratio.

Current research includes developing TOPAS, the Tool for Particle Simulation, a collaboration of UCSF, MGH and SLAC supported by NIH to improve advanced simulation of proton therapy, and developing XPERT, X-ray Plus Electron Radiotherapy, adding electrons to intensity-modulated radiotherapy with x-rays to reduce serious side-effects of radiation, especially in children. Dr. Faddegon is also working to establish image-guided radiotherapy with portal imaging for more precise targeting of tumors and avoidance of critical structures.

Dr. Faddegons clinical responsibility is physics support of linear accelerators (linacs). This includes management, installation, commissioning, maintenance and quality assurance. Highlights of Dr. Faddegon’s published clinical development work at UCSF include developing the means to treat the whole body over a short distance (3 meters), developing new x-ray targets to reduce downtime that are implemented on linacs worldwide, implementing high precision graticules for patient localization, and determining the means to detect and correct defective circuitry in treatments using virtual wedges.


University of Victoria, Victoria, Canada, B.Sc., 1977, Physics (honors)
University of British Columbia, Vancouver, Canada, M.Sc., 1983, Physics (radiobiology)
Carleton University, Ottawa, Canada, Ph.D., 1990, Physics (radiotherapy)

Professional Experience

  • 1977-80
    Geophysicist, Amoco Canada, Calgary, Alberta
  • 1982-84
    Sessional Lecturer and Laboratory Instructor, University of Victoria, Victoria, BC
  • 1984-86
    Medical Physics Resident, Ottawa Regional Cancer Center, Ottawa, Ontario
  • 1990-92
    Research Associate, Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Ontario
  • 1992-93
    Medical Physicist, BC Cancer Agency, Vancouver, BC
  • 1994-98
    Medical Physicist, Toronto-Sunnybrook Regional Cancer Center, Toronto, Ontario
  • 1994-2000
    Assistant Member, School of Graduate Studies, University of Toronto, Toronto, Ontario
  • 1998-2000
    Senior Medical Physicist, Toronto-Sunnybrook Regional Cancer Center, Ontario
  • 2000-2010
    Associate Professor in Residence, Department of Radiation Oncology, University of California San Francisco
  • 2010-present
    Professor in Residence, Department of Radiation Oncology, University of California San Francisco

Honors & Awards

  • 1980
    National Science and Engineering Research Council of Canada (NSERC) scholarship for M.Sc. studies
  • 1982
    NSERC scholarship for Ph.D. studies - declined
  • 1986
    Ontario Cancer Foundation fellowship for Ph.D. studies
  • 1988
    Ontario Graduate Scholarship for Ph.D. studies
  • 1989
    American Association Physicists in Medicine (AAPM) Young Investigator's Award, Second Prize
  • 1991
    Farrington Daniels Award (AAPM)
  • 1992
    Runner-up to Sylvia Fedoruk Prize (Canadian Organization of Medical Physics)
  • 1996
    Runner-up to Sylvia Fedoruk Prize (Canadian Organization of Medical Physics)
  • 2007
    Appointed Fellow of the American Association of Physicists in Medicine

Selected Publications

  1. Burigo LN, Ramos-Méndez J, Bangert M, Schulte RW, Faddegon B. Simultaneous optimization of RBE-weighted dose and nanometric ionization distributions in treatment planning with carbon ions. Phys Med Biol. 2019 Jan 04; 64(1):015015.
    View on PubMed
  2. Ramos-Méndez J, Burigo LN, Schulte R, Chuang C, Faddegon B. Fast calculation of nanodosimetric quantities in treatment planning of proton and ion therapy. Phys Med Biol. 2018 Nov 28; 63(23):235015.
    View on PubMed
  3. Lazar AA, Schulte R, Faddegon B, Blakely EA, Roach M. Clinical trials involving carbon-ion radiation therapy and the path forward. Cancer. 2018 Dec 01; 124(23):4467-4476.
    View on PubMed
  4. McNamara AL, Ramos-Méndez J, Perl J, Held K, Dominguez N, Moreno E, Henthorn NT, Kirkby KJ, Meylan S, Villagrasa C, Incerti S, Faddegon B, Paganetti H, Schuemann J. Geometrical structures for radiation biology research as implemented in the TOPAS-nBio toolkit. Phys Med Biol. 2018 Sep 06; 63(17):175018.
    View on PubMed
  5. Piersimoni P, Faddegon BA, Méndez JR, Schulte RW, Volz L, Seco J. Helium CT: Monte Carlo simulation results for an ideal source and detector with comparison to proton CT. Med Phys. 2018 Jul; 45(7):3264-3274.
    View on PubMed
  6. Ramos-Méndez J, Schuemann J, Incerti S, Paganetti H, Schulte R, Faddegon B. Flagged uniform particle splitting for variance reduction in proton and carbon ion track-structure simulations. Phys Med Biol. 2017 Jul 06; 62(15):5908-5925.
    View on PubMed
  7. Piersimoni P, Ramos-Méndez J, Geoghegan T, Bashkirov VA, Schulte RW, Faddegon BA. The effect of beam purity and scanner complexity on proton CT accuracy. Med Phys. 2017 Jan; 44(1):284-298.
    View on PubMed
  8. McNamara A, Geng C, Turner R, Mendez JR, Perl J, Held K, Faddegon B, Paganetti H, Schuemann J. Validation of the radiobiology toolkit TOPAS-nBio in simple DNA geometries. Phys Med. 2017 Jan; 33:207-215.
    View on PubMed
  9. Roach M, Schulte R, Mishra K, Faddegon B, Barani I, Lazar A, Blakely EA. New Clinical and Research Programs in Particle Beam Radiation Therapy: The University of California San Francisco Perspective. Int J Part Ther. 2016; 2(3):471-473.
    View on PubMed
  10. Geng C, Moteabbed M, Seco J, Gao Y, Xu XG, Ramos-Méndez J, Faddegon B, Paganetti H. Dose assessment for the fetus considering scattered and secondary radiation from photon and proton therapy when treating a brain tumor of the mother. Phys Med Biol. 2016 Jan 21; 61(2):683-95.
    View on PubMed
  11. Faddegon BA, Shin J, Castenada CM, Ramos-Méndez J, Daftari IK. Experimental depth dose curves of a 67.5 MeV proton beam for benchmarking and validation of Monte Carlo simulation. Med Phys. 2015 Jul; 42(7):4199-210.
    View on PubMed
  12. Polster L, Schuemann J, Rinaldi I, Burigo L, McNamara AL, Stewart RD, Attili A, Carlson DJ, Sato T, Ramos Méndez J, Faddegon B, Perl J, Paganetti H. Extension of TOPAS for the simulation of proton radiation effects considering molecular and cellular endpoints. Phys Med Biol. 2015 Jul 07; 60(13):5053-70.
    View on PubMed
  13. Shiao SL, Ruffell B, DeNardo DG, Faddegon BA, Park CC, Coussens LM. TH2-Polarized CD4(+) T Cells and Macrophages Limit Efficacy of Radiotherapy. Cancer Immunol Res. 2015 May; 3(5):518-25.
    View on PubMed
  14. Ramos-Méndez J, Perl J, Faddegon B, Schümann J, Paganetti H. Geometrical splitting technique to improve the computational efficiency in Monte Carlo calculations for proton therapy. Med Phys. 2013 Apr; 40(4):041718.
    View on PubMed
  15. Choi G, Huang B, Pinarbasi E, Braunstein SE, Horvai AE, Kogan S, Bhatia S, Faddegon B, Nakamura JL. Genetically mediated Nf1 loss in mice promotes diverse radiation-induced tumors modeling second malignant neoplasms. Cancer Res. 2012 Dec 15; 72(24):6425-34.
    View on PubMed
  16. Shin J, Perl J, Schümann J, Paganetti H, Faddegon BA. A modular method to handle multiple time-dependent quantities in Monte Carlo simulations. Phys Med Biol. 2012 Jun 07; 57(11):3295-308.
    View on PubMed
  17. Schreiber EC, Sawkey DL, Faddegon BA. Sensitivity analysis of an asymmetric Monte Carlo beam model of a Siemens Primus accelerator. J Appl Clin Med Phys. 2012 Mar 08; 13(2):3402.
    View on PubMed
  18. O'Shea TP, Ge Y, Foley MJ, Faddegon BA. Characterization of an extendable multi-leaf collimator for clinical electron beams. Phys Med Biol. 2011 Dec 07; 56(23):7621-38.
    View on PubMed
  19. Ge Y, Faddegon BA. Study of intensity-modulated photon-electron radiation therapy using digital phantoms. Phys Med Biol. 2011 Oct 21; 56(20):6693-708.
    View on PubMed
  20. O'Shea TP, Foley MJ, Faddegon BA. Accounting for the fringe magnetic field from the bending magnet in a Monte Carlo accelerator treatment head simulation. Med Phys. 2011 Jun; 38(6):3260-9.
    View on PubMed

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