Radio-Immunotherapy Before Cystectomy in Locally Advanced Urothelial Carcinoma of the Bladder

"Experimental intervention:~Immunotherapy with 4 cycles of Nivolumab: 240 mg intravenously every 2 weeks, starting one week before radiotherapy (week1, d1), last infusion on week 7, d1"

Neoadjuvant radiation therapy of pelvis with 45+5,4 Gy for 6 weeks: 28 x 1.8 Gy including a boost of bladder with 5.4 Gy, starting with week 2 (d1)

Radical cystectomy with standardized bilateral pelvic lymphadenectomy: performed between week 11 - 15 (Aim: week 13)