It costs around $48,000 — at least twice as much as other prostate radiation treatments. Hospitals are rushing to build proton centers, and nine are operating now — sites include Boston, Chicago, Houston, Philadelphia, Jacksonville, Fla., and Loma Linda, Calif., east of Los Angeles. Promoters often claim it is less likely to cause complications.
“There’s no clear evidence that proton therapy is better’’ for prostate cancer, and the new results suggest it may cause more complications, said Dr. Ronald Chen, a radiation specialist at the University of North Carolina, Chapel Hill.
He led the study and will give results at a medical meeting in San Francisco later this week. They were discussed Tuesday in a telephone news conference sponsored by the American Society of Clinical Oncology and two other cancer groups.
Proton therapy uses proton particles instead of X-rays. In theory, it targets radiation more directly to tumors and spares healthy tissue, which should lead to fewer side effects. Its value is established for treating eye and certain pediatric tumors. But it often is marketed for prostate cancer — a far more common condition.
Researchers checked Medicare records on more than 12,000 men treated for early-stage prostate cancers from 2002 through 2007. Follow-up information was available for four years on average.
First they compared an older version of external beam radiation to a newer form that now dominates the field — intensity-modulated radiation therapy, or IMRT. It, too, targets radiation more precisely to the prostate, and this is the first large study to show it was better than the older method — even though it came into use a decade ago.
“We found that patients who were treated with IMRT required fewer additional treatments after radiation which indicates better cancer control,’’ Chen said. There also were slightly fewer bowel problems, although there also were slightly more sexual problems among men treated with IMRT.
