A 4-week precision radiotherapy regimen is as effective and safe as the standard 8-week regimen for treating localized prostate cancer, according to research published in the Journal of Clinical Oncology (published online March 15, 2017; doi:10.1200/JCO.2016.71.7397).
Men with intermediate-risk, localized prostate cancer are often treated with external radiotherapy over an 8-week period. An alternative to standard radiotherapy is hypofractionated radiotherapy, which includes a more precise dosage of radiation to the tumor over a shorter time than standard radiotherapy. Limited data exists regarding the efficacy and safety of hypofractionated radiotherapy in comparison to the standard regimen.
Charles N Catton, MD, radiation oncologist, Princess Margaret Cancer Centre, University of Toronto (Canada), and colleagues conducted a multinational, randomized, non-inferiority trial comparing the effects of hypofractionated and standard radiotherapy in patients with intermediate-risk prostate cancer. Twenty-seven cancer centers in Canada, Australia, and France participated in the study, which began in 2005. A total of 1206 patients were assigned to receive either conventional radiotherapy of 78 Gy (39 fractions over 8 weeks, n = 598) or hypofractionated radiotherapy of 60 Gy (20 fractions over 4 weeks, n = 608).
After a 5-year follow-up, the biochemical-clinical failure disease-free survival was 85% in both groups (hazard ratio, 0.96; 90% CI, 0.77 to 1.2). No significant differences were observed between groups for grade ≥ 3 late genitourinary and gastrointestinal toxicities.
Researchers concluded that there were no clinically significant differences between the 4- and 8-week treatment regimens in regards to cancer control or toxicities, thus deeming hypofractionated radiotherapy non-inferior to standard radiotherapy.
"In fact, for some men, the shorter regimen meant slightly fewer side effects (particularly regarding bowel function) and therefore improved quality of life,” Dr Catton said in a press release (March 16, 2017).
The trial strengthened patient care by standardizing quality delivery of precision radiation techniques among participating institutions, all of which have already adopted the new treatment regimen, according to Dr Catton. – Zachary Bessette
