Stanley Benedict, M.S., Ph.D.

Stanley H. Benedict, M.S., Ph.D.


Radiation Oncology


Radiation Oncology


  • Professor
  • Vice Chair of Clinical Physics


To see if Stanley H. Benedict is accepting new patients, or for assistance finding a UC Davis doctor, please call 800-2-UCDAVIS (800-282-3284).

UC Davis Comprehensive Cancer Center

4501 X St., Suite 0144
Sacramento, CA 95817
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Additional Phone Numbers

Clinic Phone: 800-362-5566
Physician Referrals: 800-4-UCDAVIS (800-482-3284)

Philosophy of Care

The American Association of Physicists in Medicine states that the essential responsibility of a Qualified Medical Physicist's clinical practice is to assure the safe and effective delivery of radiation to achieve a diagnostic or therapeutic result as prescribed in patient care. The responsibilities of the medical physicist include: protection of the patient and others from potentially harmful or excessive radiation; establishment of adequate protocols to ensure accurate patient dosimetry; the measurement and characterization of radiation; the determination of delivered dose; development and direction of quality assurance programs; and assistance to other health care professionals in optimizing the balance between the beneficial and deleterious effects of radiation; and compliance with applicable federal and state regulations.

Clinical Interests

As the the Director of Clinical Physics Dr. Benedict works with a team of highly qualified medical physicists and dosimetrists, in accordance with the directives of radiation oncology physicians, to provide highly conformal radiation therapy treatments. A few of the systems that are employed to ensure precise set-up patient positioning, and accurate delivery include: 

  • 3D and 4D simulation and delivery confirmation 
  • Advanced treatment planning and delivery strategies such as Volumetric-modulated arc therapy (VMAT) 
  • Medical linear accelerators with on-board image guidance (Cone Beam CT)
  • Image guided brachytherapy informed by MRI and In-room mobile CT
  • Stereotactic radiation therapy (SRS with Gamma Knife and SBRT with Elekta VersaHD)

Research/Academic Interests

  1. Developing imaging tools to improve radiation therapy planning co- registration of studies for the accurate determination of tumor and target margins and critical organs at risk (OAR), including the use of MRI-PET, PET-CT, and SPECT-CT.
  2. Developing technology for image guided brachytherapy (IGBT), including 3D imaging systems (CT and MRI) for confirming applicator placement, and novel applicator designs that allow patients to be treated with minimal anesthesia (non-OR).
  3. Investigating radiobiological considerations for Hypofractionated and Stereotactic Radiosurgery treatment delivery.
  4. Designing new arc based treatment delivery approaches that incorporate modulation (gantry speed, dose rate, and MLC) for conformality, and 3D/CBCT for improved target positioning.


Radiation Oncology

Center/Program Affiliation

UC Davis Comprehensive Cancer Center


M.S., Radiological Health Physicis, San Diego State University, San Diego CA 1984

Ph.D., Biomedical Physics, UCLA, Los Angeles CA 1992

B.A., UC San Diego, La Jolla CA 1980

Board Certifications

American Board of Radiology, Therapeutic Radiological Physics,

Professional Memberships

American Association of Physicists in Medicine (AAPM)

American Society for Radiation Oncology (ASTRO)

Health Physics Society (HPS)

International Society of Therapeutic Ultrasound (ISTU)

Radiosurgery Society (RSS)

Honors and Awards

The 2015 Dean's Team Award for Excellence: (UC Davis School of Medicine) for the "Intersitital Gynecological Brachytherapy Program": Jyoti Mayadev, Edwin Alvarez, Stan Benedict, Vanessa Kennedy, Gary Leiserowitz, Gary Levin, Jeffery Uppington and Richard Valicenti, 2015

Fellow, American Association of Physicists in Medicine (AAPM), 2008

Fellow, American College of Medical Physics (ACMP), 2007

Select Recent Publications

Xiao Y, Roncali E, Hobbs R, St. James S, Bednarz B, Benedict S, Dewaraja Y, Frey E, Grudzinski J, Sgouros G, Buchsbaum JC, Capala J. Towards individualized voxel-level dosimetry for radiopharmaceutical therapy. Int J Radiation Oncol Biol Phys. 2020. Accepted/In press.

St. James S, Bednarz B, Benedict S, Buchsbaum JC, Dewaraja Y, Frey E, Hobbs R, Grudzinski J, Roncali E, Sgouros G, Xiao Y, Capala J, Xiao Y. Current Status of Radiopharmaceutical Therapy. Int J Radiat Oncol Biol Phys. 2020 Aug 14. doi:10.1016/j.ijrobp.2020.08.035.

Zhang X, Chen H, Chen W, Dyer B, Chen Q, Benedict S, Rao S, Rong Y. Technical note: Auto-segmentation of the masticatory muscles for head and neck cancer patients. J Appl Clin Med Phys. 2020 Aug. doi:10.1002/acm2.13008.

Dyer BA, Yuan Z, Qiu J, Shi L, Wright C, Benedict SH, Valicenti R, Mayadev JS, Rong Y. Clinical feasibility of MR-assisted CT-based cervical brachytherapy using MR-to-CT deformable image registration. Brachytherapy. 2020 Jul-Aug;19(4):447-456. doi:10.1016/j.brachy.2020.03.001. Epub 2020 Apr 21. PMID:32327343.

Chen W, Li Y, Dyer BA, Feng X, Rao S, Benedict SH, Chen Q, Rong Y. Deep learning vs. atlas-based models for fast auto-segmentation of the masticatory muscles on head and neck CT images. Radiat Oncol. 2020 Jul 20;15:176. doi:10.1186/s13014-020-01617-0.

He Y, Rong Y, Chen H, Zhang Z, Qiu J, Zheng L, Benedict S, Niu X, Pan N, Liu Y, Yuan Z. Impact of Different b-value Combinations on Radiomics Features of Apparent Diffusion Coefficient in Cervical Cancer. Acta Radiol. 2020 Apr;61(4):568-576. doi:10.1177/0284185119870157. Epub 2019 Aug 29. PMID:31466457.

Shi L, Rong Y, Daly M, Dyer B, Benedict S, Qiu J, Yamamoto T. Cone-beam computed tomography-based delta-radiomics for early response assessment in radiotherapy for locally advanced lung cancer. Phys Med Biol. 2020 Jan 9;65(1):015009. doi:10.1088/1361-6560/ab3247. PMID:31307024.

Yuan N, Dyer B, Rao S, Chen Q, Benedict S, Shang L, Kang Y, Qi J, Rong Y. Convolutional neural network enhancement of fast-scan low-dose cone-beam CT images for head and neck radiotherapy. Phys Med Biol. 2020 Jan;65:035003. doi:10.1088/1361-6560/ab6240.

Yuan Z, Rong Y, Benedict SH, Daly ME, Qiu J, Yamamoto T. "Dose of the day" based on cone beam computed tomography and deformable image registration for lung cancer radiotherapy. J App Clin Med Phys. 2020 Jan;21(1):88–94. doi:10.1002/acm2.12793. Epub 2019 Dec 9. PMID:31816170.

Dyer B, Yuan Z, Qiu J, Benedict S, Valicenti R, Mayadev J, Rong Y. Factors associated with deformation accuracy and modes of failure for MRI-optimized cervical brachytherapy using deformable image registration. Brachytherapy. 2019 May-Jun;18(3):378-386. doi:10.1016/j.brachy.2019.01.001.