Stereotactic body radiation therapy (SBRT) for locally advanced pancreatic cancer (LAPC)

Abstract

Introduction: SBRT would allow local control for LAPC with acceptable toxicity in a short time. The purpose of this work is to assess early and late toxicities and clinical response in patients treated with SBRT. Methods: Between October 2013 and February 2018, 48 patients with LAPC, mean age 64 years (39-84y), treated with neoadjuvant, concomitant or adjuvant chemotherapy plus SBRT were retrospectively analyzed. The treatment dose was 25 Gy to 37.3 Gy given in 3 to 5 daily fractions, utilizing volumetric arc therapy, a 6-MV photon beam and Linac Novalis IGRT-ExaTrac accelerator. GTV and OARs were delineated in CT and PET-CT fused images. OARs were contoured according RTOG criteria. The treatment planning was done in Eclipse V15.1. Acute (-3m) and late ({\textgreater}3 m) toxicities grades were classified according to the CTCAE V.3.0. Results: Of 48 LAPC patients (27 women/21 men), mean follow up 9.41m(0.23-23.77), 35 (72.91{\%}) received SBRT in pancreatic tumor as primary treatment, 11 (22.92{\%}) were operated first, followed by SBRT; and 2 patients (4.17{\%}) were rescued with SBRT because recurrence after conventional radiotherapy. 33 patients (68.75{\%}) had adenocarcinoma diagnosis, and 15 (31.25{\%}) had no biopsy. Early toxicity (48 pts) G1: asthenia in 7 (14.5{\%}), nausea in 6 (12.5{\%}) and abdominal pain in 9 (18.75{\%}); G2: asthenia in 4 (8.34{\%}), nausea in 1 (2.08{\%}) and vomiting in 1 pt. (2.08{\%}); G3: enteritis in 2 (4.17{\%}), and one of them interrupted SBRT. Fourteen patients (29.17{\%}) did not have any early toxicity. Late toxicities (21 pts) G1: enteritis in 1 (4.77{\%}) and asthenia in 2 (9.52{\%}); G3: abdominal pain in 1 (4.77{\%}) and G4 in 1 pt. (4.77{\%}) who suffered from intestinal perforation because disease progression. Relive of abdominal pain were observed in 23/48 patients after SBRT (47.92{\%}). Kaplan-Meier survival at 12 and 18 months was 46{\%} and 31{\%} respectively. Thirteen live patients kept in good shape PS0-2. Conclusion: Despite of the heterogeneity in dose and fractionation, we suggest that SBRT is a feasible and safe option for patients with pancreatic cancer.