New RTOG trial to focus on high-dose RT for prostate cancer patients
Over the last decade, the vast majority of men diagnosed with prostate cancer were found to have an early stage of the disease and no evidence that the cancer had spread to lymph nodes or other organs. Considerable research has focused on the best treatment strategy for these patients, who numbered an estimated 217,700 in 2010, and the Radiation Therapy Oncology Group (RTOG) has launched a new trial aimed at assessing quality of life outcomes in two hypofractionated radiotherapy (RT) regimens.

Recent research has indicated that the higher daily doses of radiation in fewer treatments delivered by hypofractionated RT are effective at treating prostate cancer when compared with the standard radiotherapy regimen of seven to eight weeks of treatment. The RTOG 0938 trial, A Randomized Phase II Trial of Hypofractionated Radiotherapy for Favorable Risk Prostate Cancer, led by Himu Lukka, MD, of the Juravinski Cancer Centre at McMaster University, Hamilton, Ontario, will compare two hypofractionated RT regimens which have previously been investigated individually in institutional clinical trials.

Study participants will be randomized into one of two arms to receive a radiation dose of 36.25 Gy administered twice weekly for a total of 5 treatment sessions (7.25 Gy per session) over 15 to 17 days or a dose of 51.6 Gy administered in 12 daily treatment sessions (4.3 Gy per session) over 16 to 18 days. The target trial enrollment is 174 participants at RTOG sites across North America.

“While prior studies suggest that hypofractionated RT delivery may produce comparable results to conventional therapy for patients with early stage prostate cancer, it is important to confirm this treatment strategy does not incur more adverse side effects for patients,” Lukka said in a statement. “If a hypofractionated regimen is found to produce comparable findings to conventional treatment, it would be more convenient for patients who are now treated over a course of 39 to 41 treatment sessions and would result in substantial healthcare cost savings.”

To compare health-related side effects between the hypofractionated trial arms and conventional RT treatment, study participants will complete a health-related quality of life questionnaire at one, two and five years after receiving treatment to provide information about their treatment side effects related to bowel and bladder function. These data will be compared to those collected with the same questionnaire from study participants who participated in a previously conducted RTOG trial and were randomized to the trial’s conventional arm.

“We are fortunate to have the RTOG 0415 benchmark data to determine if either hypofractionation regimen is promising enough for further investigation in a phase III study comparing one or both arms of RTOG 0938 to current standard radiotherapy,” said Lukka.

Study participants will be able to participate in companion surveys collecting information about the trial’s hypofractionated RT treatment effects on their general health and on sexual function.

Favorable patient outcomes in this phase II trial would lead to a larger phase III trial to investigate the treatment strategy’s therapeutic benefits.