Proton therapy delivers much less radiation to nontargeted normal tissues than does conventional radiation therapy.
"Quality of life following treatment of prostate cancer is a critical issue for patients, and they need to be well informed of all treatment options, including proton therapy, prior to making any final treatment decision," Dr. Bradford S. Hoppe from University of Florida Proton Therapy Institute, Jacksonville, Florida, told Reuters Health in an email.
Dr. Hoppe led a new study of health-related QOL, with an emphasis on sexual outcomes, in 262 men up through age 60 who received definitive treatment for prostate cancer with proton therapy alone.
Seventy-eight percent of the men had T1c disease, 17% had T2a, 4% had T2b, and 1% had T2c or T3a.
After a median follow-up of 24 months (range, 6-53), only one man had developed a biochemical recurrence.
On the Expanded Prostate Cancer Index Composite (EPIC) questionnaire, urinary incontinence scores worsened only slightly, from 95.8 at baseline to 92.2 at two years, at which point only 1.8% of men reported using a pad to manage urge incontinence. (The best possible EPIC score is 100.)
Potency rates declined by 11% from baseline through two years. At that point, 94% of nondiabetics with a body mass index below 30 and a baseline International Index of Erectile Function (IIEF) score above 21 (on a scale of 5 to 25) were potent.
Nearly three-quarters of men (73%) reported "no erectile dysfunction" or "mild erectile dysfunction" after two years, compared with 86% at baseline, and the number of men actively engaging in sexual intercourse at least weekly only dropped by 11% at two years.
Higher penile bulb mean dose and higher proton therapy dose independently lowered sexual summary scores, whereas only diabetes significantly impaired potency.
"Proton therapy is an effective prostate cancer treatment for men under 60, with reduced risk of side effects like incontinence and impotence that may be improvements over surgical outcomes," Dr. Hoppe concluded.
"We do intend to continue following these men to evaluate disease control and quality-of-life issues and will hopefully be able to report five-year results in the future," he added.
By Will Boggs MD
Last Updated: 2012-02-28 20:00:09 -0400 (Reuters Health)
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