Intestinal Low-Dose Radiotherapy Combined With Immune Checkpoint Inhibitors in Solid Tumors With Liver Metastases

This study aims to evaluate the effectiveness and safety of combining low-dose radiotherapy to the intestines with immune checkpoint inhibitors (ICIs) in patients with liver metastases from solid tumors. Liver metastases often create an "immune desert" that makes immunotherapy less effective. Recent research has shown that low-dose irradiation of the gut (1 Gy) can reshape the gut microbiome and activate the immune system, potentially reversing resistance to immunotherapy. This is a prospective, single-arm, single-center cohort study. We plan to enroll 120 patients with liver metastases from non-small cell lung cancer (NSCLC), colorectal cancer, or pancreatic cancer. All participants will receive a single low dose of radiotherapy to the intestine (1 Gy), followed by standard immune checkpoint inhibitors and chemotherapy. The main goal of this study is to see how well the liver metastases respond to this combined treatment. We will also monitor survival, side effects, and changes in the gut bacteria and blood immune markers to understand how this treatment works. This strategy may provide a low-cost, low-toxicity new option for patients whose liver metastases have stopped responding to standard immunotherapy.