ASTRO Updates Clinical Guidelines for Hypofractionated Radiation Therapy in Prostate Cancer

An updated clinical guideline from the American Society for Radiation Oncology (ASTRO) offers evidence-based recommendations on the use of hypofractionated radiation therapy for patients with localized prostate cancer. This guideline replaces ASTRO's 2018 recommendations and reflects a matured evidence base indicating that shorter-course radiation therapy can maintain cancer control while alleviating the overall treatment burden for patients undergoing definitive external beam radiation therapy (EBRT). The guideline was published in Practical Radiation Oncology, ASTRO's clinical practice journal.

Approximately one in eight men will receive a prostate cancer diagnosis during their lifetime, making it the second most common cancer among men in the United States, following skin cancer. In 2026, nearly 334,000 new cases of prostate cancer are projected among U.S. adults, with generally excellent outcomes for patients when diagnosed at a localized stage.

For patients with localized prostate cancer opting for radiation therapy, EBRT is a standard definitive treatment. Hypofractionated EBRT utilizes fewer treatment sessions than conventional approaches, delivering higher doses per treatment while maintaining a similar overall therapeutic effect. Moderate hypofractionation is typically administered over four to six weeks, while ultrahypofractionation, often delivered as stereotactic body radiation therapy (SBRT), allows completion of treatment in just five sessions across one to two weeks.

The updated guidelines advocate for moderate hypofractionation over conventional fractionation for patients across all risk groups choosing EBRT, backed by high-quality randomized data that demonstrate comparable outcomes, side effects, and quality of life. Ultrahypofractionation is strongly recommended as a standard option for many patients, particularly those with intermediate-risk disease, thus extending the application of five-treatment SBRT in prostate cancer management.

Key recommendations emphasize shared decision-making between physicians and patients, particularly when treatment options differ by risk group, baseline urinary function, and patient preferences.

For patients receiving EBRT for localized prostate cancer, moderate hypofractionation is recommended across all risk groups, with randomized trials supporting its effectiveness. It remains recommended irrespective of patient age, comorbidity, anatomy, or baseline urinary function.

Ultrahypofractionated EBRT is recommended for patients with low-risk localized prostate cancer who opt out of active surveillance, as well as for those with intermediate-risk disease. The guideline conditionally recommends ultrahypofractionated EBRT for high-risk and very high-risk patients.

Recommendations also address treatment planning and delivery, favoring precision approaches such as MRI-informed planning and daily motion management. The guideline highlights the importance of equitable access to high-quality hypofractionated radiation therapy, given its potential to reduce burdens associated with care delivery.

The guidelines were developed by a multidisciplinary task force involving oncological specialists and were endorsed by several professional organizations, reflecting the collaborative effort to update the standard of care in prostate cancer treatment.