479 Background: To assess the effects of pelvic radiotherapy (RT) on orthotopic neobladder reconstruction (ONR), this review presents retrospective data of surgical outcomes following prior RT. Methods: Our institutional IRB approved bladder cancer database was queried for all patients who underwent radical cystectomy and ONR between 1980 and 2018. Radiation data was abstracted from the electronic medical record (EMR) with inclusion of patients receiving >40 Gy to the pelvis prior to surgery. Surgical outcomes including estimated blood loss (EBL), operative time, margin status, overall survival (OS), and need for subsequent surgeries were evaluated. Results: Of 2117 ONRs performed, 96 patients received prior RT. Of those, RT details could be obtained on 24 patients. Fifteen patients underwent definitive bladder RT with a median dose of 6480 cGy (range, 4500 - 8640 cGy); 7 of these patients received concurrent chemoradiotherapy, 2 received chemotherapy and RT with timing uncertain, and 6 received RT alone. Eight patients had prior prostate RT (median 7200 cGy) and one patient underwent prior cervical RT (7910 cGy). The median time interval between bladder RT and ONR was 7 months (range, 2 – 116 months) verses a median of 29 months between other pelvic RT and ONR (range, 6 – 163 months). Median EBL was 875 cc (range, 200-3000 cc) in patients with prior pelvic RT. Median operative time was 355 minutes (range, 231-600) in those who had prior RT compared with 354 minutes (range, 111-778) in those who underwent ONR without prior RT. Twenty-three patients had negative margins on surgical resection and one had a positive ureteral or urethral margin. The median OS following surgery was 50 months. Two patients died within 1 year due to disease progression. Seven patients (29%) required a surgical intervention after ONR: two patients developed fistulas (both with pouch to cutaneous fistulas), four patients had artificial urinary sphincters placed, and one developed small bowel obstruction due to adhesions. One patient required urethrectomy for recurrent disease. Conclusions: Orthotopic ileal neobladder reconstruction after pelvic irradiation is feasible with acceptable functional results.
