HDRT Appears Superior to CDRT for All Stages of Prostate Cancer

High-dose radiation therapy (HDRT) proved superior to conventional dose treatments in a recent meta-analysis that targeted the effects both have on survival and recurrence for patients with prostate cancer.

A meta-analysis of data obtained from randomized controlled studies of HDRT versus conventional-dose radiation therapy (CDRT) showed that higher doses were superior in preventing biochemical failure for low-, intermediate- and high-risk prostate cancer patients. The doses ranged from 64 Gy to 79.2 Gy in the studies analyzed by Gustavo Arruda Viani, M.D., Eduardo Jose Stefano, M.D. and Sergio Luis Afonso, M.D., of the radiation oncology department at the Marilia School of Medicine department in Sa˜o Paulo, Brazil. Their study, “Higher-than-conventional Radiation Doses in localized Prostate Cancer Treatment: A Meta-analysis of Randomized, Controlled Trials,” was published in the online Red Journal in August.

The authors identified seven studies with a patient population of 2,812 in a search conducted in the Medline Embase, Cancerlit and Cochrane Library databases. Dose-response relationships were established with a meta-regression analysis.

A distinct dose-response relationship supports using HDRT, concluded the researchers. Higher radiation doses significantly reduced the incidence of biochemical failure, but didn’t affect the mortality rate and specific prostate cancer mortality rates.

“The presence of a dose-response relationship supports the use of HDRT because CDRT may increase the recurrence risk,” said the authors. “Although the highest effective radiotherapy dose has not yet been identified, it could be higher than 90 Gy. However, because significant differences in late Grade greater than two rectal toxicity were seen between HDRT and CDRT groups, further trials of IGRT and IMRT to deliver doses higher than 80 Gy should be conducted with the goal to maintain the therapeutic index at a satisfactory level.”