TO STUDY THE RESPONSE RATE OF HYPO-FRACTIONATED BLADDER PRESERVATION RADIOTHERAPY IN MUSCLE INVASIVE BLADDER CANCER

Objective: To determine the response rate of hypofractionated bladder-preservation radiotherapy in patients with muscle-invasive bladder cancer according to RECIST criteria. Study Design: Descriptive case series. Place and Duration of Study: Department of Radiotherapy, Institute of Nuclear Medicine & Oncology (INMOL), Lahore, from June 2025 to September 2025. Methodology: A total of 66 patients aged 25–70 years with histopathologically confirmed muscle-invasive bladder cancer (T2–T4a, N0–N1, M0) and ECOG performance status 0–1 were enrolled using non-probability consecutive sampling. Results: The mean age of patients was 49.8 ± 11.6 years, and 78.8% were males. Complete response was observed in 74.2% of patients, partial response in 13.6%, stable disease in 7.6%, and progressive disease in 4.6%, yielding an overall response rate of 87.8%. Response rates were highest in T2-stage tumors and declined with advancing tumor stage. Grade III toxicity occurred infrequently, and treatment interruption was required in only 3.0% of patients. Conclusion: Hypofractionated bladder-preservation radiotherapy achieves a high response rate with acceptable acute toxicity in muscle-invasive bladder cancer, representing an effective and well-tolerated bladder-sparing treatment option for appropriately selected patients.