From Thomas Jefferson University
Sexual function, quality of life, maintained in prostate cancer patients after 3D conformal therapy as compared to seed implants
One issue to consider with radiation therapy to treat early prostate cancer is its potential effect on a man's sexual function. This can influence both the patient's and doctor's choice of treatment. A survey by radiation oncologists at Jefferson Medical College has shown that all things being equal, patients with early stage prostate cancer who had standard 3D conformal radiation - radiation with a beam - are much more likely to retain sexual function similar to before treatment than those who received standard radiation therapy and radiation through implanted "seeds." Such seeds, implanted in the prostate, emit tiny bursts of radiation aimed at destroying cancer cells.
Richard Valicenti, M.D., assistant professor of radiation oncology at Jefferson Medical College of Thomas Jefferson University in Philadelphia, and his co-workers at Jefferson and at the University of Virginia gave 188 men with localized prostate cancer - disease confined to the prostate - a questionnaire before and after treatment asking them to compare their sexual function. The survey was repeated every three months for four years.
In the study, 128 patients had 3D therapy alone, while 60 had 3D therapy and also received implants. Only 26 received external beam therapy alone. Dr. Valicenti's team found that those who received 3D conformal therapy were as much as three times more likely to report sexual function similar to before their treatment. He reports the results May 14 at the annual meeting of the American Society of Clinical Oncology in San Francisco.
"External beam and implants affected quality of life and sexual function the most compared to either therapy alone," Dr. Valicenti says. "They were the least likely to have sexual function preserved. This information is very important because quality of life questions influence decisions by patients and physicians on a particular therapy.
"Patients and doctors need to know about these results because it's a prospective study," Dr. Valicenti says. "We have a good assessment of how a patient is able to preserve sexual function and quality of life after treatment. The results indicate that patients who received 3D conformal therapy, seed implants and hormonal therapy are significantly less likely to preserve sexual function and quality of life after two years."
According to Dr. Valicenti, after one year, 67 percent of the patients receiving 3D conformal therapy alone reported an overall quality of life either similar to or better than before treatment. "That compared to 65 percent of the patients who received 3 D conformal therapy with hormones, versus 56 percent who received prostate seed implants without external beam," he notes. Only 22 percent of those men who received a more rigorous treatment of both external beam therapy and implants said their quality of life and sexual function was similar to before surgery.
The results were unexpected. "We thought patients with implants would be more likely to preserve sexual function," he says. According to this study, however, "different mechanisms of action might be affecting sexual function after treatment with individual therapies." Hormonal therapy didn't appear to matter, having little affect on patients' sexual function after two years, he notes. The survey results, Dr. Valicenti says, need to be validated with a larger study.
Editors: This information is embargoed for release May 14, 2001 at 8 a.m. PT at the annual meeting of the American Society of Clinical Oncology in San Francisco (Abstract no. 759)