PURPOSE: To report 5-year clinical outcomes of 3 prospective trials of image-guided proton therapy for prostate cancer.
METHODS AND MATERIALS: A total of 211 prostate cancer patients (89 low-risk, 82 intermediate-risk, and 40 high-risk) were treated in institutional review board-approved trials of 78 cobalt gray equivalent (CGE) in 39 fractions for low-risk disease, 78 to 82 CGE for intermediate-risk disease, and 78 CGE with concomitant docetaxel therapy followed by androgen deprivation therapy for high-risk disease. Toxicities were graded according to Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. Median follow-up was 5.2 years.
RESULTS: Five-year rates of biochemical and clinical freedom from disease progression were 99%, 99%, and 76% in low-, intermediate-, and high-risk patients, respectively. Actuarial 5-year rates of late CTCAE, version 3.0 (or version 4.0) grade 3 gastrointestinal and urologic toxicity were 1.0% (0.5%) and 5.4% (1.0%), respectively. Median pretreatment scores and International Prostate Symptom Scores at >4 years posttreatment were 8 and 7, 6 and 6, and 9 and 8, respectively, among the low-, intermediate-, and high-risk patients. There were no significant changes between median pretreatment summary scores and Expanded Prostate Cancer Index Composite scores at >4 years for bowel, urinary irritative and/or obstructive, and urinary continence.
CONCLUSIONS: Five-year clinical outcomes with image-guided proton therapy included extremely high efficacy, minimal physician-assessed toxicity, and excellent patient-reported outcomes. Further follow-up and a larger patient experience are necessary to confirm these favorable outcomes.
Written by:
Mendenhall NP, Hoppe BS, Nichols RC, Mendenhall WM, Morris CG, Li Z, Su Z, Williams CR, Costa J, Henderson RH. Are you the author?
University of Florida Proton Therapy Institute, Jacksonville, Florida; Division of Urology, College of Medicine, University of Florida, Jacksonville, Florida.
Reference: Int J Radiat Oncol Biol Phys. 2014 Mar 1;88(3):596-602.
doi: 10.1016/j.ijrobp.2013.11.007
PubMed Abstract
PMID: 24521677
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