Post-operative image guided intensity modulated radiation therapy (IG-IMRT) in prostate cancer patients yields low toxicity and excellent quality of life outcomes, according to a study conducted by researchers at Princess Margaret Cancer Centre/University Health Network in Toronto.
Despite proven benefits, IMRT after prostate surgery is reportedly under-utilized, and researchers suspect that's because patients have quality of life concerns relevant to outcomes achieved with inferior radiation techniques.
For prostate cancer patients, urinary and bowel issues are a concern, as well as sexual function issues after treatment. "Older techniques showed some negative impact on quality of life, and with the newer techniques (which can better preserve the healthy/normal tissues) you could expect a lesser (negative) impact," Dr. Alejandro Berlin, a lead author of the study, told HCB News in an e-mail.
In this case — using IMRT in combination with daily cone beam CT — the results are promising.
Berlin and his team looked at 68 men — around 60 years old — undergoing radiation therapy (RT) after prostatectomy at the Princess Margaret Cancer Centre, Toronto, hospital between August 2007 and October 2008. Of them, 53 showed evidence of recurrent disease (e.g. rising PSA after previous surgery without adjuvant radiation therapy) while the remaining 15 were undergoing adjuvant RT directly following surgery.
Toxicity was graded according to the National Cancer Institute's Common Terminology Criteria for Adverse Events. The researchers reported that cumulative incidence of late gastrointestinal Grade 2 toxicities was 12.3 percent and genitourinary Grade 2 toxicities was 10.6 percent. No Grade 3 or Grade 4 late toxicities were observed.
Using the Expanded Prostate Cancer Index Composite (EPIC) questionnaire, the researchers surveyed patient outcomes periodically over the ensuing five years after treatment. Although survey participation declined with time, gastrointestinal and genitourinary scores showed "transient decline" in the short term and complete recovery between three and 12 months post-treatment.
The sexual quality of life remained stable at five years, with a reduction in how "bothered" the patients were by sexual dysfunction, with the five-year mean score at 58.17 versus 44.81 at baseline. Berlin speculates that improvement could be attributed to patients becoming accustomed to erectile dysfunction over time.
