Outcomes Of Head And Neck Squamous Cell Carcinomas (Hnscc) Treated With Reirradiation (Rrt) At Mayo Clinic

6064 Background: RRT is offered as definitive (DRRT) or post-operative (PRRT) treatment for patients (pts) with loco-regionally recurrent (LRR) or new primary (NP) HNSCC in previously irradiated volumes. We report the results of a retrospective chart review of all consecutive pts with LRR and NP HNSCC treated with DRRT and PRRT at Mayo Clinic. Methods: We included LRR and NP HNSCC pts treated with DRRT/PRRT from 2003-2011 at all Mayo Clinic campuses. Patient and treatment related data were collected. Loco-regional recurrence rate (LR) and distant metastases rate (DM) at 2 years, and overall survival (OS) from end of RRT using Kaplan-Meier methods, were calculated. Results: We identified 89 pts (68 M, 21 F). 67 pts had LRR; 22 NP. Treatment included salvage surgery with PRRT (47 pts) and DRRT (42 pts). 30 pts received concurrent chemotherapy (CT) with PRRT; 33 DRRT pts received CT. Median prior RT dose was 66 Gy (26.4 – 79.2 Gy). Median PRRT dose was 60 Gy (11 – 70 Gy). Median DRRT dose was 69.6 Gy (18 – 7...