Evaluate the Efficacy and Safety of Radiotherapy Combined With Ripretinib in the Treatment of Unresectable Advanced GIST

Inclusion Criteria: * Voluntary participation and signed informed consent; * age: 18 to 75 years, Male or female * Patients with histologically confirmed GIST and Imaging evaluated as unresectable recurrent and metastatic disease or locally advanced. * ECOG Performance Score: 0-2 * Subjects who have progressed or documented intolerance after previous first-line, second-line, and third-line treatments. * At least one measurable lesion in the abdominal or pelvic cavity that has progressed after frontline treatment * Adequate organ function and bone marrow reserve Exclusion Criteria: * estimated life-expectancy less than 3 months. * Patients who have received previous radiotherapy to the proposed radiotherapy site, or the tumor has significant mobility, poor tolerance of radiotherapy in adjacent organs, and who are considered unsuitable for radiotherapy after MDT discussion * Any other clinically significant comorbidities, which in the judgment of the investigator, could compromise compliance with the protocol, interfere with interpretation of the study results, or predispose the patient to safety risks. * If female, the patient is pregnant or lactating, or plans to become pregnant during the study treatment period