Condensing radiotherapy for high-risk prostate cancer patients into 25 sessions by increasing the radiation dose of each treatment offers similar overall survival, progression-free survival, biochemical control rates, and toxicity profiles as the standard treatment of 39 fractions, according to a study presented at the Genitourinary Cancers Symposium in Orlando, FL.
Lead author Michael Wang, MD, of the Cross Cancer Institute and the University of Alberta, Edmonton, Alberta, said he and colleagues studied 100 high-risk prostate cancer patients, who had hypofractionated intensity-modulated radiotherapy from 2005 to 2012 and followed them for a median 5.4 years. In this condensed radiotherapy regimen, patients received a total of 68 Gy in 25 treatment sessions, versus the standard regimen where patients received a total of 78 Gy in 39 treatment sessions.
“Overall survival at the 5-year mark was 88.7%. Progression-free survival at 5 years was 92.8%. Biochemical control rate at 5 years was 91.8%. So, with 25 treatments, at higher dose per fraction, the clinical outcomes are comparable to the standard regimen of 39 fractions,” said Dr. Wang, who worked on the study with Nawaid Usmani, MD, and colleagues.
Radiotherapy hypofractionation isn’t a viable option for all cancers, according to Dr. Wang. Prostate cancer is amenable because it is slow-growing and extremely sensitive to radiation treatment. An already-published study by Dr. Wang’s team shows acceptable acute toxicity profiles in patients who get hypofractionated radiation treatment for high-risk prostate cancer (Int J Radiat Oncol Bio Phys 2010; 76:57-64).