An Exploratory Study of the Efficacy and Safety of SBRT Following Induction Therapy With Neoadjuvant Immunotherapy Combined With Chemotherapy in Muscle-Invasive Bladder Cancer

Inclusion Criteria:

• Those who voluntarily sign the informed consent form, understand the nature, purpose and procedures of this trial and voluntarily comply with the trial requirements;
• Male or female, aged between 18 and 85 years;
• Patients with pathologically confirmed MIBC;
• Those who meet the new adjuvant treatment criteria for MIBC and have not undergone tumor-related treatment before;
• Patients with clinical tumor stage of cT2-T4aN0M0;
• Male participants or potentially pregnant females must use highly fertile males or potentially pregnant females during the trial, must use highly effective contraceptive methods (such as oral contraceptives, intrauterine devices, inhibitory methods or contraceptive methods combined with spermicides) during the test, must use contraceptive methods combined with spermicides at the end of the treatment, and use contraception for 12 months after the treatment;
• The main organ functions simultaneously meet the following standards: 1) Absolute neutrophil count ≥ 1.5 × 109/L; 2) Platelets ≥ 90 × 109/L; 3) Hemoglobin ≥ 90 g/L; 4) Serum creatinine ≤ 1.5 times the upper limit of normal (ULN); 5) Serum total bilirubin ≤ 1.5 times ULN (except for those with Gilbert syndrome); 6) Aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) ≤ 1.5 times ULN; 7) International normalized ratio (INR), activated partial thromboplastin time (APTT) ≤ 1.5 times ULN.
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2;
• People who have the intention to preserve their bladder.

Exclusion Criteria:

• Pregnant or lactating women, as well as women who wish to conceive (pelvic radiotherapy may cause premature aging of the ovaries);
• Patients with stage IV bladder cancer with distant metastasis;
• Those with a history of primary malignant tumors in other parts;
• Those with severe organ dysfunction, such as recent cerebrovascular disease, or with diseases or factors that can cause cerebral edema or intracranial hypertension; severe heart diseases or discomfort, including but not limited to the following diseases/factors: 1) Currently suffering from untreated or uncontrollable hypertension (systolic pressure > 180 mmHg and/or diastolic pressure > 100 mmHg) or unstable angina pectoris; 2) According to the New York Heart Association (NYHA) classification standard, currently having a history of any level of congestive heart failure or severe need for treatment of arrhythmia (except for atrial fibrillation or paroxysmal supraventricular tachycardia); 3) History of myocardial infarction within the previous 6 months; 4) Patients with pacemakers; significantly reduced liver function or liver reserve function, active liver disease; severe renal parenchymal or renal vascular lesions, renal insufficiency; severe respiratory dysfunction; uncorrected moderate-to-severe anemia; obvious bleeding tendency or DIC tendency;
• Subjects with a known history of mental illness, poor compliance;
• Those who cannot tolerate neoadjuvant chemotherapy or immunotherapy, radiotherapy;
• Women of childbearing age, who do not agree to take one or more effective contraceptive measures during the treatment period and at least 6 months after the last study treatment; with a positive blood pregnancy test;
• Those considered by the investigators to be unsuitable for enrollment or may not be able to complete this trial for other reasons;
• Other situations that the review personnel from the registration study consider to be unqualified based on the registration: such as potential situations inconsistent with the clinical protocol.