A faster and less expensive form of radiotherapy, called Stereotactic body radiotherapy (SBRT), for treating prostate cancer may come with a higher rate of urinary complications.

The standard external beam radiation therapy for prostate cancer is currently intensity modulated radiation therapy (IMRT). Stereotactic body radiotherapy delivers a greater dose of radiation per treatment than IMRT so  patients receiving SBRT can complete an entire course of treatment in one to two weeks, compared to seven to nine weeks for IMRT. 

A new study in the Journal of Clinical Oncology by researchers at Yale Cancer Center compared IMRT to SBRT in a national sample of 4,005 Medicare patients age 66 and older receiving prostate cancer treatment. Participants received either SBRT or IMRT as a primary treatment for prostate cancer during 2008 to 2011. 

"All the reports we have about the toxicity of SBRT comes from pioneering institutions," said first author James Yu, M.D., assistant professor of therapeutic radiology at Yale Cancer Center. "But now that SBRT is being used nationally, it is important to determine the costs and complications on a national level."

Yu, senior author Cary Gross, M.D., and their colleagues found that the mean per-patient cost to Medicare for a course of SBRT was about $13,600, compared to $21,000 for IMRT. The team found that at 24 months after the start of the treatment, there were increased side effects for SBRT compared to IMRT, due to urethral irritation, urinary incontinence, and obstruction. However, even when including the cost of treating complications, the overall medical costs due to SBRT were still lower than that of IMRT.

"While these data are by no means definitive, our findings emphasize the need to carefully assess the impact of new cancer treatment technologies in actual practice," said Gross, professor of internal medicine at Yale School of Medicine, and director of the Yale COPPER Center at Yale Cancer Center.