This is a prospective cohort study to analyse the safety and efficacy of postoperative adjuvant radiotherapy combined with immunotherapy versus surgery alone group of UTUC patients with T3-4 stages or lymph nodes metastasis(N+) status.

This study is a prospective cohort study.

1. Observation group: patients in the observation group were T3-4,N+ pyeloureteral cancer patients who did not tolerate chemotherapy or refused chemotherapy after radical surgery. No treatment will be given after surgery, and regular review will be conducted.
2. Postoperative immunotherapy+radiotherapy group:

Adjuvant immunotherapy: the immunotherapy drug choice is tirilizumab, which has been recommended in metastatic uroepithelial cancer in China. Tirelizumab 200mg Q3w; the duration of immunotherapy is recommended to be used for at least 1 year.

Adjuvant radiotherapy can be given concurrently or sequentially with adjuvant immunotherapy; it is recommended that radiotherapy can be started within 4-6 weeks after surgery. Rotational intensity-modulated radiotherapy (VMAT), daily image-guided radiotherapy (Daily IGRT) technique is used.

Irradiation range:

Renal pelvis and upper ureter: ipsilateral renal fossa, para-abdominal aorta (including upper ureteral alignment area), common iliac lymph node area; Middle and lower ureteral carcinoma: parabasal abdominal aorta (renal hilar vessels and following levels), common iliac lymph node area (right side needs to include paraventricular lymph node area) + internal and external iliac lymph node area + middle and lower ureteral alignment area, entrance of the ureteral bladder.

Radiotherapy dose: 45-50Gy/25f/5w, 62.5Gy/25f/5w regimen was given to suspected metastatic lymph nodes visible on imaging. Ensure that normal tissue is within the dose limits.

Note: The right tumour para-abdominal aortic lymph node drainage area needs to include: para vena cava + intervening vena cava + left para-abdominal aorta Left tumour para-abdominal lymph node drainage area needs to include: intervening vena cava + left para-abdominal aorta

Inclusion Criteria:

• 1) Patients after radical nephroureterectomy with full-length nephroureterectomy and pathologically confirmed cancer of the renal pelvis or ureter, AJCC staging (8th edition) containing one of the following factors: pT3-4, pN+; 2) Patients with creatinine eGFR <60 min/L. or underlying disease refusing to tolerate chemotherapy.

3)18≤age≤80 years old; 4)Completion of abdominopelvic CT 4 weeks prior to enrolment. 5)Except for cutaneous non-melanoma and ductal carcinoma in situ of the breast, the patient has not suffered from any other malignant disease within the last 5 years; 6)Willing to participate in perfecting the necessary examinations and follow-up visits for the sake of the study, and willing to provide written informed consent.

All of the above need to be fulfilled:

Expected survival > 6 months; KPS > 70 points; Leukocytes ≥ 3.5 x 109/l,Neutrophils ≥ 1.5 x 109/l, Platelets ≥ 100.0 x 109/l, Haemoglobin ≥ 90g/l.

Exclusion Criteria:

• 1) Distant metastases already found at the time of surgery; non-R0 resected patients 2) History of pelvic and abdominal radiotherapy; history of inflammatory bowel disease; history of systemic chemotherapy; (3) Pregnant or breastfeeding women; or women of childbearing potential who are not using reliable contraception; (4) History of malignant tumour (except skin cancer that is not malignant melanoma and cervical cancer in situ, tumours that have been cured for more than 5 years) 5) weight loss > 10% within 6 months 6) Presence of active infections in those with pre-existing or co-existing bleeding disorders 7) clinically significant cardiac disease (e.g., hypertension controlled by medication, unstable angina pectoris, New York Heart Association (NYHA) class ≥ II congestive heart failure, unstable symptomatic arrhythmia, or class ≥ II peripheral vascular disease); 8) Psychological, family, and social factors leading to lack of informed consent.

All pT3-4/N+ UTUC patients who were eligible for enrolment and signed the informed consent could be included in the study.