Project Summary

PCORI has identified the need for large studies that look at real-life questions facing diverse patients, caregivers, and clinicians. In 2014, PCORI launched the Pragmatic Clinical Studies initiative to support large-scale comparative effectiveness studies focusing on everyday care for a wide range of patients. The Pragmatic Clinical Studies initiative funded this research project.

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

Prostate cancer is one of the most common cancers and a leading cause of cancer death among men in the United States. About one-third of all men with prostate cancer get treatment with a type of radiation called photon therapy. This treatment can cause bowel and bladder damage and sexual dysfunction. These side effects can worsen patients’ quality of life. Proton therapy is another treatment option. But researchers don’t know how well proton therapy works compared with photon therapy or what dose of proton therapy works best.

In this study, the research team is comparing photon therapy to proton therapy. The team wants to know how each treatment affects patients’ quality of life, side effects, and risk of cancer coming back. Also, the team is testing two different doses of proton therapy to see if shorter, higher dose treatment is as safe and effective as longer, lower dose treatment.

Who can this research help?

Doctors and patients can use these results when considering how to treat prostate cancer. Insurance companies may also use the results when considering the benefits and harms of these treatments.

What is the research team doing?

The research team is working with cancer clinics around the country to recruit men with localized prostate cancer, or cancer that hasn’t spread to other areas in the body. The team is recruiting 1,500 patients at clinics that provide photon therapy and 1,500 patients at clinics that provide proton therapy. All men in the study receive either photon or proton therapy as part of their regular care. The team is surveying patients before and during treatment and again three months and one, two, and three years later. The survey asks patients about their quality of life and treatment side effects. Every six months for three years, the team is also checking to see if the prostate cancer has come back.

The 1,500 patients receiving proton therapy can choose to take part in another study. In this other study, the research team is assigning patients to receive one of two proton therapy regimens by chance. Half of the patients receive eight weeks of therapy with a standard dose. The other half receives four weeks of therapy with a higher dose at each treatment. The team wants to know whether quality of life, side effects, and cancer recurrence differ between standard therapy and higher dose therapy.

Patients, caregivers, prostate cancer advocacy groups, insurers, and companies that make radiation equipment helped to design and are helping to conduct the study.

Research methods at a glance

Design Elements Description
Design Pragmatic clinical trial and randomized controlled trial
Population 3,000 men ages 30–85 with localized prostate cancer and a life expectancy ≤8 years
  • Photon therapy
  • Proton therapy
    • Proton arm 1: standard proton therapy 78.0 Gy (RBE) in 39 fractions
    • Proton arm 2: hypofractionated proton therapy 60.0 Gy (RBE) in 20 fractions

Primary: prostate cancer quality of life (bowel, urinary, and sexual dysfunction symptoms)

Secondary: toxicity of adverse events, prostate cancer recurrence

Timeframe 2-year follow-up for primary outcome

Project Information

Nancy Mendenhall, MD
Ronald Chen, MD, MPH
University of Florida Board of Trustees
A Prospective Comparative Study of Outcomes with Proton and Photon Radiation in Prostate Cancer^

Key Dates

November 2017
July 2027

Study Registration Information

^This project was previously titled: Comparing Radiation Treatments for Localized Prostate Cancer


Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: March 14, 2024