Patients receiving hypofractionated external-beam radiation therapy (EBRT) for early-stage prostate cancer experienced similar outcomes and toxicities as those receiving standard radiation at lower doses over a longer period of time, the American Society for Radiation Oncology, American Society of Clinical Oncology, and American Urological Association say in a new clinical guideline.

The guideline cited conclusive evidence from several large, well-designed randomized trials that a shorter, more intense course of EBRT has similar disease control and side effects, although data on outcomes beyond five years is limited. Additionally, the guideline noted a small increase in the risk for short-term gastrointestinal toxicity with hypofractionated EBRT.

Hypofractionated EBRT typically allows patients to complete treatment in four to five weeks, which is about half of the time for standard radiation. Ultrahypofractionated EBRT (i.e., stereotactic) has an even shorter course—as few as five treatments—but the guideline only recommends it for low-risk patients and preferably in a clinical trial or registry setting.