Radiotherapy Combined with Systemic Therapy Versus Systemic Therapy for Oligometastatic UTUCs

Inclusion Criteria: * Patients with metastatic uroepithelial cancer with histologically confirmed diagnosis (pathologically confirmed primary focus or one of the metastatic foci is sufficient) (metastasis after total cystectomy, metastasis after full-length nephroureteral resection, or metastatic uroepithelial cancer of the pelvic-ureteral bladder at the first diagnosis of inoperable metastatic uroepithelial cancer). * Oligometastases were defined as ≤3 organs, and the number and size of metastatic lesions were not restricted to the extent that full-coverage radiotherapy could be met. If regional lymph node recurrence was present, all positive regional lymph nodes were collectively referred to as one lesion. Non-regional lymph node metastases are counted as metastases by lymph node subregion. * Willing and able to provide written informed consent/assent for the trial; age ≥18 years on the date of signing the informed consent form and patient age ≤80 years. * Expected survival time ≥ 6 months; * Eastern Collaborative Oncology Group (ECOG) Physical Status (PS) score of 0 to 1; * Normal major organ function, i.e., the following criteria are met: routine blood tests: a) Haemoglobin ≥ 90 g/L; b) Total bilirubin ≤ 2 x upper limit of normal (ULN); c) Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) ≤ 2.5 x ULN in the absence of liver metastases, and ALT, AST and ALP ≤ 5 x ULN in the presence of liver metastases; d) Creatinine clearance (CrCl) ≥30 mL/min; Exclusion Criteria: * Pathological type non-urothelial carcinoma; * Patients with brain metastases and \>3 liver metastases; patients with spinal bone metastases at risk of spinal cord compression; patients with pericardial, pleural or abdominopelvic fluid; * Patients who are intolerant to or have had a reduction in systemic therapy; patients with tumour progression assessed after 2 cycles of systemic therapy.