ASTRO 2020: Hypofractionated Photon Versus Proton Therapy for Prostate Cancer
Posted: Sunday, November 1, 2020
Both moderately hypofractionated photon therapy and proton beam therapy appear to be safe for patients with low- or moderate-risk prostate cancer, according to a study presented at the virtual edition of the 2020 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 4058). Regardless of therapy choice, the researchers found low rates of late genitourinary and gastrointestinal toxicities. No factors were identified that significantly predicted genitourinary toxicity, and anticoagulant use was the only significant predictor of gastrointestinal toxicity.
Patients with low or intermediate-risk prostate cancer “cannot make a wrong decision—both forms of treatment are safe and effective,” Jessica Karen Wong, MD, MEng, of the Fox Chase Cancer Center, Philadelphia, stated in an institutional press release.
The researchers prospectively identified and evaluated 1,850 patients with intact low- or intermediate-risk prostate cancer from across 7 cancer centers throughout the nation. The study population included patients who underwent hypofractionated photon therapy (n = 1,282) or proton beam therapy (n = 568). Follow-up was conducted 4 to 6 years after treatment. Late toxicity was defined as occurring more than 3 months after treatment completion.
The adjusted late genitourinary toxicity rate was 2.0% versus 3.9% for patients treated with proton therapy compared with photon therapy, respectively (odds ratio [OR] = .47). Although higher rates of gastrointestinal toxicity were recorded with proton therapy, the difference was no longer significant after adjusting for covariates. Anticoagulant use was the only factor that significantly predicted gastrointestinal toxicity (OR = 1.88). The most common late toxicity for patients who received proton therapy was urinary bleeding and for those given photon therapy, it was cystitis. Rectal bleeding was a common late toxicity for both groups.
Disclosure: For full disclosures of the study authors, visit redjournal.org.