Gastric Cancer Peritoneal Metastasis (GCPM)

This study is a prospective, single-center, open-label, exploratory phase II clinical trial aimed at evaluating the safety, tolerability, and preliminary efficacy of low-dose radiotherapy (LDR) sequentially combined with serplulimab, bevacizumab analog, and irinotecan or albumin-bound paclitaxel in patients with gastric cancer and peritoneal metastases. A total of 40 patients with gastric adenocarcinoma who have previously undergone first-line therapy are planned for enrollment. Patients will be grouped based on prior exposure to paclitaxel-based chemotherapy to determine whether they will receive systemic treatment with irinotecan combined with serplulimab or albumin-bound paclitaxel combined with serplulimab, along with local intraperitoneal infusion of bevacizumab analog. The study adopts a Simon two-stage design, with 20 patients enrolled in the first stage. If ≥3 patients achieve objective remission, the study will proceed to the second stage, enrolling an additional 20 patients.