Ultrahypofractionation Versus Conventional Fractionation in Prostate Cancer
Posted: Monday, August 19, 2019
Anders Widmark, MD, of Umeå University in Sweden, and colleagues published a noninferiority trial in The Lancet, indicating ultrahypofractionated radiotherapy is a viable treatment of prostate cancer. In their study, ultrahypofractionated radiotherapy was found to be noninferior to conventionally fractionated radiotherapy for men with intermediate- to high-risk prostate cancer.
This phase III HYPO-RT-PC trial enrolled 1,200 patients with intermediate to high-risk prostate cancer from 12 different sites in Sweden and Denmark between July 2005 and November 2015. Patients were randomly assigned to receive either ultrahypofractionation (42.7 Gy in 7 fractions, 3 days/week for 2.5 weeks) or conventional radiotherapy (78.0 Gy in 39 fractions, 5 days/week for 8 weeks). Of the patients included in the study, 89% were considered to have intermediate-risk and 11% high-risk disease.
After a median follow-up of 5 years, the estimated failure-free survival was 84% in both treatment groups, establishing noninferiority of the ultrahypofractionated therapy. Overall survival at 5 years for patients receiving the conventional therapy was 96%, compared with 94% for the ultrahypofractionated group.
“Early side effects are more pronounced with ultrahypofractionation compared with conventional fractionation, whereas late toxicity is similar in both treatment groups,” they reported. However, there was weak evidence of an increase in the frequency of acute physician-reported Radiation Therapy Oncology Group morbidity scores of grade 2 or worse urinary toxicity in the group receiving ultrahypofractionation therapy (28% vs. 23%). There were no differences seen in grade 2 or higher urinary or bowel late toxicity between the two groups at any point after the conclusion of radiotherapy, but the ultrahypofractionated group did have a higher rate of urinary toxicity at 1 year (6% vs. 2%).
Disclosure: The study authors reported no conflicts of interest.