Biologically effective doses of 60-70Gy vs. >70Gy of stereotactic body radiotherapy (SBRT) combined with chemotherapy in locally advanced pancreatic cancer: protocol of a phase III study

Abstract Background: There is controversial on the correlation between biologically effective dose (BED, α/β=10) of stereotactic body radiation therapy (SBRT) and clinical outcomes of patients with locally advanced pancreatic cancer (LAPC). Therefore, the aim of the study is to compare the survival benefits of BED10 of 60-70Gy with those of BED10＞70Gy.Methods: This study is a multicenter study. Patients with LAPC are randomly allocated into two groups. Arm1: SBRT with BED10 of 60-70Gy in 5-6 fractions combined with gemcitabine plus albumin-bound paclitaxel; Arm2: SBRT with BED10＞70Gy in 5-6 fractions combined with gemcitabine plus albumin-bound paclitaxel. The primary outcome is progression-free survival (PFS). The secondary outcomes are radiation-induced gastrointestinal (GI) toxicity, local control (LC) and overall survival (OS).Discussion: The pilot phase Ⅲ study could provide evidence for further decision making of prescription doses of SBRT for LAPC, which may improve survival outcomes without compromise of quality of life. The trial protocol has been approved by the Ethics committee of Shanghai Changhai hospital. The ethics number is CHEC2020-100.Trial registration: Clinical trials number: NCT04603586. Date of registration: 10/27/2020.