This study aims to evaluate the clinical feasibility of first-line immunochemotherapy for stage IVB and recurrent cervical cancer guided by circulating tumor DNA (ctDNA), in order to explore the optimal treatment duration or criteria for discontinuation of first-line immunotherapy in patients with stage IVB cervical cancer or recurrent cervical cancer. To ensure the quality of the study, before the study begins, the research applicant and participants jointly discuss and formulate the research plan. Necessary steps should be taken during the design and implementation stages of the study to ensure that the collected data is accurate, consistent, complete, and credible.