New X-ray approach targets prostate cancer

The results of a small study suggest that a new type of radiation treatment called stereotactic body radiotherapy is a safe and effective alternative to standard radiation therapy for early prostate cancer.

With stereotactic body radiotherapy, X-rays are used to more precisely target the body sites where the radiation is delivered. As a result, higher doses of radiation can be given, which allows for a shorter treatment course compared with conventional radiation therapy.

"There is great enthusiasm in reducing the length of treatment for prostate cancer while also possibly improving its effectiveness, and these early results are very promising for men with early prostate cancer," lead author Dr. Christopher King, from Stanford University School of Medicine, California, said in a statement.

The findings, reported in the International Journal of Radiation, Oncology, Biology, Physics, come from a study of 41 men who underwent stereotactic body radiotherapy for 5 days.

During nearly 3 years of follow-up, none of the patients experienced any severe complications to the rectum, a body site that can be damaged when radiation is directed at the prostate. Two patients did, however, experience less severe urinary problems.

The side effects of stereotactic body radiotherapy are on par with what is seen with other radiation treatments for prostate cancer, the authors note. Moreover, they found that giving the radiation doses every other day rather than every day helped reduce the rate of complications.

Blood tests confirmed that the new form of radiation therapy was effective against early prostate cancer and none of the patients had evidence that their tumor had returned.

While the findings are encouraging, King acknowledged that longer follow-up of these patients is needed. "It can often take as long as 10 years to see late side effects and recurrences, so we will have to monitor these men closely and cautiously pursue these treatments further before we can confidently say that stereotactic body radiotherapy is as good as other proven prostate cancer treatments."

SOURCE: International Journal of Radiation, Oncology, Biology, Physics, March 15, 2009.