Surgical outcomes of patients with pancreatic cancer treated with stereotactic body radiation therapy.

Abstract

341 Background: The surgical outcome of patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma (BRPC/LAPC) treated with stereotactic body radiation therapy (SBRT) is unclear. Methods: A comparative study was performed to determine if surgical outcomes were different among patients receiving neoadjuvant SBRT vs chemoradiation therapy (CRT) vs chemotherapy only. Results: Between 2011 and 2014, 29 patients with BR/LA-PDAC underwent neoadjuvant chemotherapy and SBRT (6.6 Gy x 5 fractions) followed by pancreatectomy. Eighteen of 29 patients (62%) had LAPC. Their outcomes were compared with 82 patients who received neoadjuvant CRT and 26 patients who received neoadjuvant chemotherapy only (Table). When compared to neoadjuvant CRT and chemo only, the neoadjuvant SBRT group had a higher R0 resection rate (90% vs 84% vs 62%, p=0.02) and vascular resection rate (41% vs 13% vs 31%, p=0.005), respectively. Although the vascular resection and complication rates (Clavien grade 3 or above) were higher in the neoadjuvant SBRT group, no in-hospital mortality was encountered. In the SBRT group, the complete pathological response rate (21%) was higher than that of the other groups (4% and 0% respectively, p<0.001). Survival will be updated later as the current median postoperative follow-up is 6 months in the SBRT group. Conclusions: Neoadjuvant chemotherapy and SBRT is associated with improved surgical outcomes and pathologic complete response rates in selected patients with BRPC/LAPC. Longer follow-up is needed to determine its impact on survival. [Table: see text]