BERKELEY, CA (UroToday.com) - Dose escalation has been associated with significantly improved biochemical control rates in several prospective randomized trials.
This benefit is compromised by the disadvantage of increased rectal toxicity. These trials started more than 10 years ago, so that conventional conformal radiotherapy (3DCRT) was applied.
Major technical advances that are increasingly adopted for EBRT for localized prostate cancer are intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT). In comparison to 3DCRT, dose conformity can be improved using the IMRT technique. The application of IGRT before each fraction for prostate localization is the crucial prerequisite for the reduction of safety margins to account for prostate motion.
The aim of this study is the comparison of health-related quality of life (QoL) changes after 3DCRT with total doses of 70.2 to 72 Gy versus dose-escalated IMRT up to 76 Gy. Matched pairs were selected to ensure 2 comparable patient groups. All patients have been surveyed prospectively before, at the last day, a median of 2 months and 16 months after RT using a validated questionnaire (Expanded Prostate Cancer Index Composite). Criteria for 78 matched pairs after IMRT versus 3DCRT were patient age, antiandrogens use, treatment volume (± whole pelvis), risk group prognostic, and urinary/bowel/sexual quality of life (QoL) before treatment.
Urinary, bowel, sexual, and hormonal function scores were similar in the 3DCRT versus IMRT groups before, but likewise after treatment, the mean or median score changes did not differ > 5 points at any interval. The only statistically significant difference was found for the sexual function score changes at time D (mean 9 versus 6 points; p = 0.04).
A statistically significant difference was found, considering the percentage of patients reporting frequent painful bowel movements at time C (10% after 3DCRT versus 1% after IMRT; p = 0.03). However, a tendency for larger rectal bleeding rates was found after IMRT at time D (> rarely in 20% after IMRT versus 9% after 3DCRT; p = 0.06). A great or moderate problem with bloody stools was reported in 7% after IMRT versus 1% after 3DCRT (p = 0.09). Focusing only on patients who did not report any rectal bleeding before EBRT, 17% versus 8% reported at least rare rectal bleeding after IMRT versus 3DCRT (p = 0.08). Stool incontinence was less frequently after IMRT. In contrast to patients after IMRT, uncontrolled leakage of stool (> rarely) has been reported significantly more often in comparison to the baseline percentage by patients after 3DCRT (p = 0.04). Patients with erections firm enough for intercourse before treatment lost this ability in 35% after IMRT versus 68% after 3DCRT (p = 0.03).
In summary, the application of technological advances (IMRT and IGRT) for dose escalation is not associated with increased morbidity for patients with prostate cancer. Advantages found in this study were a faster recovery of pain during bowel movements, insignificantly increased stool incontinence relative to baseline levels, and better long-term erectile function.
Pinkawa M, MD., Et Al., as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.