Higher Biologically Effective Dose Predicts Survival in SBRT of Pancreatic Cancer: A Multicentric Analysis (PAULA-1)

Abstract

Aim: The purpose of the present multicentric study was to review stereotactic body radiotherapy (SBRT) with or without chemotherapy (CHT) experience in locally advanced pancreatic cancer (LAPC). Endpoints were overall survival (OS), local control (LC), and distant metastasis-free survival (DMFS). Several parameters' impact on these outcomes was assessed.

Materials and methods: Fifty-six patients with LAPC undergoing SBRT+/-CHT were included. SBRT median BED_α/β10Gy was 48.0 Gy (range=28.0-78.7). Survival curves were calculated by Kaplan-Meier method. A Cox regression model was fitted.

Results: At a median follow-up of 15.0 months, 2-year OS, LC, DMFS were: 33.8% 55.4%, and 22.9%, respectively. Patients treated with BED_α/β10Gy≥48 Gy showed improved OS (p=0.020) and LC (p=0.024). At multivariate analysis, BED_α/β10Gy≥48 Gy was significantly associated to both higher OS (p=0.042) and LC (p=0.045), while post-SBRT CHT improved DMFS (p=0.003).

Conclusion: SBRT proved to be tolerable and effective in LAPC. Moreover, BED_α/β10Gy≥48 Gy was significantly correlated with improved OS and LC.

Keywords: Pancreatic cancer; chemotherapy; dose effect; stereotactic body radiotherapy.