Speaker: Dr. Guncha Maheshwari
Dr. Guncha Maheshwari: Hi, my name is Dr. Guncha Maheshwari and I am a senior resident in the Department of Radiation Oncology at the Tata Memorial Centre, Mumbai. On behalf of my co-authors, I am excited to present the results of a recently published study on late urinary toxicity and quality of life in patients treated with pelvic radiotherapy for high-risk prostate cancer. The POP-RT was a phase III randomized control trial comparing whole pelvic radiation versus prostate-only radiation in patients with high-risk node negative prostate cancer. The whole pelvic radiation resulted in significant benefit in the biochemical failure-free survival disease-free survival, as well as metastasis-free survival. However, with similar impact on the overall survival at a five year follow-up. This came at an expense of a slightly higher grade 2+ urinary toxicities graded as per the RTOG which was nearly 20% with the whole pelvic radiation versus 8.9% with the prostate-only radiation. With this background, we thought of exploring the late urinary toxicities and their possible influencing factors in this trial cohort. At a long term follow-up, the cumulative urinary toxicities were graded as per the CTCAE which allowed for symptom- wise analysis as well as we did explore the urinary quality of life domains for all these patients and we also performed a multivariable logistic regression analysis for possible influencing factors. The bladder dosimetry was also seen in 5- Gy increments from V5 to V65 to see if any of the urinary toxicity symptoms or the overall toxicity grade 2 was associated with the same. At a follow-up of 75 months, we found that the grade 3 urinary toxicities were similar in both the arms to the tune of 5% and 4.1%, and the grade 2 urinary toxicities were nearly 10% higher with the whole pelvic radiation, which was approximately 31.3% versus 22.7% with the prostate-only radiation. However, this difference was not significant statistically. The urinary quality of life domains were also similar among both the arms and the multivariable analysis for age, trial arm, stage of the tumor, known diabetes, prior TURP, any acute grade 2 urinary toxicity and bladder volumes receiving doses of 10Gy and 40Gy did not identify any significant causative association. In short, we hope that this study assures radiation oncologists around the world that whole pelvic radiation is safe for high-risk prostate cancer and the grade 3 toxicities is limited to 5% and similar. We are yet to see if the overall survival curves separate at a long-term follow-up Thank you.
