Dose escalated concurrent chemo-radiation in borderline resectable and locally advanced pancreatic cancers with tomotherapy based intensity modulated radiotherapy: A phase II study

Background: We report the response and outcomes of borderline resectable and locally advanced pancreatic cancer (BRPC & LAPC) patients treated with dose escalated neoadjuvant intensity modulated radiotherapy (IMRT). Methods: Thirty newly diagnosed patients with BRPC (n=18) and LAPC (n=12) (NCCN criteria V 2.2.12) were accrued in this prospective study from 2008-2011. All patients received neoadjuvant chemoradiation (NACRT) using Helical Tomotherapy (dose of 57 Gy over 25 fractions to the gross tumor volume (GTV) and 45 Gy over 25 fractions to suspected microscopic extension) along with weekly gemcitabine. Results: Fifteen patients (50%) had a partial response. A complete metabolic response (CMR) on PET was seen in 9 patients (30%). Among BRPC, 9 patients (50%) were surgically explored and 7 underwent R0 resection (39%). The median follow up of surviving patients was 85 [interquartile range (IQR): 64.5-85.8] months. The median progression free survival (PFS) was 13 months for BRPC and 8.8 months for LAPC. The median overall survival (OS) was 17.3 months for BRPC and 11.8 months for LAPC. Among patients undergoing R0 resection, the median PFS and OS was 27 and 35.5 months respectively. Conclusions: Dose escalated radiotherapy with concurrent chemotherapy is feasible and can downsize some tumors resulting in surgery in about 39% of the BRPC.