April 16, 2012 -- The most popular form of radiation therapy for prostate cancer may also be the best, a new comparison study finds.
Nearly all men with prostatecancer who opt for external beam radiation get a treatment called intensity-modulated radiation therapy or IMRT. IMRT has almost entirely replaced another type of radiation treatment called 3D conformational therapy -- even though it's much more expensive, with little head-to-head evidence showing it works better.
And there's an even newer and even more expensive prostate cancer treatment: proton beam therapy. More and more medical centers are spending hundreds of millions of dollars to build new proton beam therapy centers.
Which treatment really offers a man the best chance of a prostate cancer cure with the fewest side effects? IMRT, according to Ronald C. Chen, MD, MPH, and colleagues at the University of North Carolina at Chapel Hill.
"For prostate cancer in this country, we have completely adopted IMRT," Chen tells WebMD. "I don't see anybody going back to 3D therapy. And thankfully, our study does show it is better in terms of cancer control and reducing long-term side effects. So IMRT is here to stay."
Chen's team didn't conduct a clinical trial. Instead, they compared results for similar Medicare patients who underwent IMRT, 3D conformational therapy, or proton beam therapy for prostate cancer. The data came from Medicare-linked records from the huge U.S. Surveillance Epidemiology and End Results (SEER) database.
The study analyzed data from 6,666 men treated with IMRT, 6,310 men treated with 3D conformational therapy, and 684 men treated with proton beam therapy.
Men treated with IMRT were 19% less likely to need additional cancer treatment compared to men treated with 3D conformational therapy.
Men treated with IMRT were 12% more likely to suffer erectile dysfunction than were men treated with 3D conformational therapy.
Men treated with IMRT were 22% less likely to be diagnosed with hip fractures and 9% less likely to have gastrointestinal problems than were men treated with 3D conformational therapy.
There was no difference in the need for additional cancer treatment between men treated with IMRT and those treated with proton beam therapy.
Men treated with IMRT were 34% less likely to suffer gastrointestinal events than were men treated with proton beam therapy.
"The use of IMRT has skyrocketed in the past 10 years and it's good to see that this study affirms the use of IMRT to reduce side effects and to reduce the risk of additional therapy," Louis Potters, MD, chair of radiation medicine at North Shore University Hospital, Manhasset, N.Y., tells WebMD.
Potters, who was not involved in the Chen study, says that IMRT costs more than 3D radiation, and that the new findings "validate" the procedure.