Postoperation Maintenance Therapy for Resectable Liver Metastases of Colorectal Cancer Guided by ctDNA

The goal of this clinical trial is to compare in resectable liver metastases colorectal cancer patients.The main question it aims to answer is to investigate whether the progression-free survival (PFS) of resectable colorectal liver metastasis (CRLM) patients with positive ctDNA after surgery is superior with the combination of adjuvant chemotherapy and maintenance therapy compared to adjuvant chemotherapy alone.