Three-Dimensional Conformal Radiotherapy with Concomitant Boost and Weekly Cisplatin in Muscle-Invasive Transitional Cell Bladder Carcinoma

Abstract

Background: Local control of MIBC by bladder-sparing approach is unsatisfactory. In order to improve the effectiveness of radiotherapy, we have designed a protocol that combines TURB with a non-conventionally fractionated radiotherapy "concomitant boost. Aim of Study: To evaluate the response rate and toxicity criteria in patients with transitional cell bladder cancer treated with maximum Transurethral Resection (TUR), followed by 3-D conformal radiotherapy with a concomitant boost and weekly cisplatin with shortening of overall treatment time. Patients and Methods: Between July 2017 to June 2018, 20 patients with a T2-T3 N0M0 transitional cell carcinoma of the bladder underwent transurethral resection of bladder tumor as much as safely possible (maximum TURBT). They received radiotherapy delivered in short overall treatment time with a concomitant boost technique. With this technique, a dose of 40Gy in 2-Gy fractions was administered to the small pelvis with a concomitant boost limited to the bladder tumor area plus a margin of 15Gy in fractions of 0.75Gy. The total tumor dose was 55Gy in 20 fractions in 4 weeks. Weekly Cisplatin (30mg/m 2) was administered weekly concurrently with radiotherapy. Cisplatin was interrupted in case of hematological or renal toxicity. The National Cancer Institute Common Toxicity Criteria, version 5, scale was used to assess the chemotherapy and acute radiation toxicity {Common Terminology Criteria for Adverse Events (CTCAE), Version 5.0, November 2017}. We assessed late toxicity using The Radiation Therapy Oncology Group/The European Organization for Research and Treatment of Cancer (RTOG/EORTC) Late Radiation Morbidity Scoring Scheme. Results: The feasibility of the treatment was good. Severe acute toxicity >!G3 was observed in two patients (10%). Severe late toxicity >!G3 was observed in one patient (5%). Fourteen patients (70%) showed a complete and three (15 %) a partial remission after treatment. Conclusion: In external radiotherapy for muscle-invasive bladder cancer a concomitant boost technique coupling a