All the patients then completed questionnaires regarding treatment side effects six months, 12 months, and 24 months following radiation.
Older age, as well as poor sexual function prior to radiation, did increase the risk for sexual impairment after radiation treatment, the researchers said. However, they report no appreciable difference in sexual function between the men receiving the shorter course/higher dose regimen or the more conventional regimen.
"The key to curing more prostate cancer is to give higher does of radiation," observed Horwitz. "And over the last few years, more and more men have been getting higher dose radiation, because the radiation oncology community knows that dose matters and that low dose radiation is just not effective compared to high dose. And this study shows that we have the ability to give these high doses in different ways, and in all these ways, men do very well."
Horwitz said he and his colleagues plan to take the current research to the next level.
"We will build on this experience and go with even higher doses," he said, "to see how that impacts not only sexual function but urinary and bowel function as well."
Dr. Peter T. Scardino is chairman of the department of urology and head of the Prostate Cancer Program at the Memorial Sloan-Kettering Cancer Center in New York City. He described the finding as a small but important step toward developing shorter course/higher dose radiation therapies.
"This is the trend nowadays," said Scardino. "This is where this is going: toward a time when perhaps we will be giving radiation therapies all in a single day."
"Animal studies have already indicated that you may be able to achieve as much or more with a single dose of radiation than with a protracted course," Scardino noted. "So, the big question is, are you going to find more complications as a result of this kind of a shift in dosage? Now, cutting back from seven and a half weeks to five weeks is a slight move in this direction, but they found no difference in sexual side effects, and that's valuable. And I certainly think we'll be seeing a lot more research in this area."
More information
There's more on radiation therapy for prostate cancer at the American Cancer Society.
