Aim: In India, the incidence of prostate cancer is low and patients are usually diagnosed in an advanced stage of the disease. Patients with localized high risk prostate cancer usually undergo androgen deprivation therapy (ADT) and whole pelvic radiation. This study aimed to assess the impact of radiation on urinary toxicity in Indian men with prostate cancer undergoing WP-IMRT utilizing CBCT image guidance. Materials and methods: In 2010, our centre acquired a linear accelerator with CBCT. The cohort consisted of 44 patients with localized high risk prostate cancer, treated with ADT and WPIMRT between 2010 and 2016. WP-IMRT (4680 cGy) was followed by an IMRT boost (2520 to 3200cGy) or moderate Hypofractionation (6625 cGy) based on the tolerance of organs at risk. Image guidance was done by daily CBCT prior to radiation. Urinary symptoms of the patients were assessed by recording the International Prostate Symptom Score (IPSS) prior to starting radiation (baseline) and during each follow up. The initial scores were analyzed and compared with the scores on follow up. The IPSS scores were categorized into three groups namely mild (0-7), moderate (8-19) and severe (>19). Results: The median follow up was 18.5 months (range 4-66 months) and median total RT dose was 7560cGy (range 6625-7880cGy). Initially, the Pre-treatment IPSS score of 40.9% of the patients was mild, 47.7% of the patients was moderate and 11.4% of the patients was severe. But after 24 months, the IPSS score of 64.3% of the patients was mild, 35.7% of patients was moderate and none were severe. Conclusion: Patients undergoing WP-IMRT experience urinary toxicity. However, this resolves within within 6 to 24 months and majority of patients do not experience any significant long term urinary toxicity. This indicates that radiation dose escalation with WPIMRT is well tolerated by high risk prostate cancer patients. [ABSTRACT FROM AUTHOR]