UT Southwestern Reports 99% Cure Rate for Prostate Cancer With SBRT

High-dose radiation beams intersect at desired target

A five-year study has shown that stereotactic body radiation therapy (SBRT) to treat prostate cancer offers a higher cure rate than more traditional approaches, according to researchers at the University of Texas Southwestern Medical Center.

The team reported a 98.6% cure rate with SBRT, a noninvasive form of radiation treatment that involves high-dose radiation beams entering the body through various angles and intersecting at the desired target. The state-of-the-art technology allows a concentrated dose to reach the tumor while limiting the radiation dose to surrounding healthy tissue.

“The high cure rate is striking when compared to the reported five-year cure rates from other approaches, like surgery or conventional radiation, which range between 80 to 90%, while the side effects of this treatment are comparable to other types of treatment,” said lead author Dr. Raquibul Hannan, an assistant professor of radiation oncology at UT Southwestern. “What we now have is a more-potent and effective form of completely noninvasive treatment for prostate cancer, conveniently completed in five treatments.”

“The current form of radiation is 44 treatments given over nine weeks. In contrast, the SBRT therapy we used allows the delivery of highly focused radiation in only five treatments, allowing patients to return to their normal lives more quickly,” said senior author Dr. Robert Timmerman. “SBRT is both more convenient and has increased potency.”

UT Southwestern served as the lead site for the multi-institutional study, which involved first-time prostate cancer patients diagnosed with stage I or stage II (low- or intermediate-risk) prostate cancer. A total of 91 patients were treated prospectively and were followed for five years, with only one patient experiencing a recurrence of his cancer. The findings were published in the European Journal of Cancer.

In the short term, the adverse effects of SBRT may include urinary issues (urgency, frequency, and burning) and rectal irritation, which are usually temporary and resolve within four weeks of treatment. The researchers found a small risk of longer-term urinary and rectal complications, which was comparable with that of conventional treatments. Decreased erectile function occurred in 25% of patients, fewer than with conventional radiation or surgery, Hannan said.

To reduce the adverse effects of SBRT, ongoing clinical trials at UT Southwestern are using a unique biodegradable rectal spacer gel to protect the rectum. UT Southwestern is the only accredited site in Texas at which this gel can be used.

Source: UT Southwestern Medical Center; April 18, 2016.