A Study of Proton Radiation Divided into Fewer Doses for Low Risk Prostate Cancer


  • Study type

  • Study phase

  • Study IDs

  • Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • During the early phases (phases 1 and 2), researchers assess safety, side effects, optimal dosages and risks/benefits. In the later phase (phase 3), researchers study whether the treatment works better than the current standard therapy. They also compare the safety of the new treatment with that of current treatments. Phase 3 trials include large numbers of people to make sure that the result is valid. There are also less common very early (phase 0) and later (phase 4) phases. Phase 0 trials are small trials that help researchers decide if a new agent should be tested in a phase 1 trial. Phase 4 trials look at long-term safety and effectiveness, after a new treatment has been approved and is on the market.

  • Site IRB
    • Scottsdale/Phoenix, Arizona: 16-001523
    • Rochester, Minnesota: 16-001523
    NCT ID: NCT01230866
    Sponsor Protocol Number: GU002-10

About this study

The purpose of this study is to compare the effects (good and bad) on patients with prostate cancer by comparing the standard dose of radiation therapy (44 treatments over 8½-9 weeks) with a higher daily dose of radiation (5 treatments over 1-2 weeks) to see if the effects of the treatments are similar or better.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

Inclusion Criteria

  • Histologically confirmed prostate adenocarcinoma within 365 days prior to randomization
  • History/physical examination with digital rectal examination of the prostate and baseline toxicity assessment within 90 days prior to randomization
  • Histological evaluation of prostate biopsy with assignment of a Gleason score to the biopsy material
    • Gleason score must be in the range of 2-6
    • > 6 cores are strongly recommended
  • PSA values < 10 ng/ml within 90 days prior to randomization
    • Either done prior to biopsy or at least 21 days after prostate biopsy
  • Clinical stages T1a-T2a N0 M0 (AJCC Criteria 7th Ed.)
    • Staging must be done by treating investigator
  • No pelvic lymph nodes > 1.5 cm in greatest dimension unless the enlarged lymph node is biopsied and negative
  • Must be at least 18 years old
  • ECOG performance status 0-1 (appendix I) documented within 90 days prior to randomization
  • IPSS score < 16
  • Must give IRB approved, study specific, informed consent
  • Must complete all mandatory tests listed in section 4.0 within the specified time frames
  • Must be able to start treatment within 56 days of randomization

Exclusion Criteria

  • Previous prostate cancer surgery to include prostatectomy, hyperthermia and cryosurgery
  • Previous pelvic radiation for prostate cancer
  • Androgen deprivation therapy prior to radiation is allowed 
    • It is not acceptable if continued during radiation or as adjuvant therapy
  • Active rectal diverticulitis, Crohn's disease affecting the rectum, or ulcerative colitis
  • Prior systemic chemotherapy for prostate cancer
  • History of proximal urethral stricture requiring dilatation
  • Current and continuing anticoagulation with warfarin sodium (Coumadin, heparin, low-molecular weight heparin, clopidogrel bisulfate (Plavix)or equivalent) unless it can be stopped to manage treatment related toxicity, to have a biopsy if needed, or for marker placement
  • Any major medical, addictive or psychiatric illnesses which would affect the consent process, the completion of treatment and/or interfere with follow-up
    • Consent by legal authorized representative is not permitted in this study
  • Evidence of any other cancer within the past 5 years and < 50% probability of a 5 year survival
    • Prior or concurrent diagnosis of basal cell or non-invasive squamous cell cancer of the skin is allowed

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Carlos Vargas, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office


Rochester, Minn.

Mayo Clinic principal investigator

Carlos Vargas, M.D.

Contact us for the latest status

Contact information:

Cancer Center Clinical Trials Referral Office


More information


Publications are currently not available

Study Results Summary

Not yet available

Supplemental Study Information

Not yet available


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