How to cite: Davis BJ. Proton Therapy for Prostate Cancer. Grand Rounds in Urology. October 23, 2025. Accessed Oct 2026. https://grandroundsinurology.com/proton-therapy-for-prostate-cancer/
Summary
Brian J. Davis, MD, PhD, FABS, Professor of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, examines the role of proton radiation therapy in the management of prostate cancer, with a focus on distinguishing established advantages from commonly cited overstatements. Dr. Davis reviews the physical principles of proton therapy, including the Bragg peak and the distinction between passive scattering and active scanning proton beams. He emphasizes that while proton therapy offers clear dosimetric advantages in selected disease sites, its benefits in prostate cancer require careful qualification.
Dr. Davis reviews the evolution of the Mayo Clinic’s proton centers, culminating in the implementation of scanned beam proton therapy and proton stereotactic body radiation therapy (SBRT). He discusses clinical scenarios where proton therapy provides meaningful advantages.
Dr. Davis summarizes results from a prospective clinical trial conducted at Mayo Clinic that compares moderate hypofractionation with conventional fractionation in patients with nodal-only recurrence.
The presentation details Mayo Clinic’s four-field proton SBRT approach when combined with hydrogel spacers to treat localized prostate cancer. Dosimetric analyses show reductions in rectal and femoral head dose without compromising target coverage. Utilization data demonstrate that although prostate cancer represents a substantial proportion of treated patients, it accounts for a smaller fraction of total proton treatment time due to SBRT fractionation.
Dr. Davis critically addresses common claims about proton therapy, identifying several as overstatements when applied to prostate-only radiation. He reviews randomized data from the PARTIQoL trial, which show no differences between proton therapy and IMRT in biochemical control or patient-reported quality of life. He emphasizes that while proton therapy is valuable and appropriate in selected circumstances, outcomes for prostate-only radiation are comparable to IMRT, reinforcing the importance of evidence-based patient counseling.
About the 28th Annual Southwest Prostate Cancer Symposium:
Presented by Program Chairs Nelson N. Stone, MD, Richard G. Stock, MD, and William K. Oh, MD, this conference educated attendees about advances in the management of localized and advanced prostate cancer, with a focus on imaging, technology, and training in the related devices. It included a scientific session, as well as live demonstrations of surgical techniques.
ABOUT THE AUTHOR
Brian J. Davis, MD, PhD, FABS, is a Professor of Radiation Oncology at Mayo Clinic in Rochester, Minnesota. Dr. Davis also serves as a consultant for the Department of Radiation Oncology and the Department of Physiology & Biomedical Engineering at Mayo Clinic. He specializes in genitourinary cancer, and his research interests include prostate cancer, proton therapy, intensity-modulated radiation therapy, external beam radiotherapy, and brachytherapy.
