Trimodality Therapy in which Concurrent Chemoradiation with Concomitant Boost in Muscle Invasive TCC Urinary Bladder Cancer

BACKGROUND: Bladder cancer is the most common genitourinary tract malignancy among Egyptian males (16%). bladder sparing therapy can be considered an alternative for patients refusing surgery or are not candidates for surgery. The objective of this study was to determine the safety and feasibility of external-beam irradiation with concomitant boost in muscle invasive bladder cancer and to determine the short-term (1-year) risk of recurrence of bladder cancer. METHODS: Between October 2019 and November 2021, we enrolled 42 patients in Prospective, one arm trial. Eligible patients had pathologically confirmed TCC transitional cell carcinoma of the bladder cT2-4aN0M0, who refused surgery or had contraindications to surgery, and treated conservatively with radiotherapy. All patients underwent maximal TURB before beginning of chemoradiation therapy which was delivered in all patients The patients received radiotherapy dose 45 Gy/25 fractions (1.8 Gy) per fraction to the whole bladder+ 3 cm. with concurrent cisplatin 20 mg/ m(2) over 30 minutes before radiation on days 1,2,15,16,29, and 30. Additionally, concomitant boost limited to the bladder plus1.5 cm margin was deliverd during the last ten days of the treatment with a minimum 6 h gap between fractions, to a total dose 60 Gy, with the overall treatment time equal to 5 weeks. RESULTS: The median overall survival OS for 42 patients with transitional cell carcinoma( TCC) of bladder treated with 3D conformal radiotherapy 3DCRT and concomitant boost was 28 months, the mean OS was 29.9±1.04, and (95% confidence interval=27.9-32). The one-year OS was 100%, 2-year OS was 81%, and 3-year OS was 26.2%.The mean loco-regional relapse free survival (LRRFS) was 31.6±1.8, 95% CI=28.1-35.1, and the median was 26.5±1.4, the one-year loco-regional RFS was 92.9%, and 2-year (LRRFS) was 66.7%.Acute and late genitourinary toxicity was grade 2 in most of patients and also acute and late toxicity of gastrointestinal was equal or less than grade 1. CONCLUSION: In external radiotherapy for muscle invasive bladder cancer a concomitant boost technique of invasive bladder cancer with shortening of the overall treatment time provides a high probability of local control and overall survival with acceptable toxicity.