A Prospective Registry Study of Stereotactic Ablative Radiotherapy (SABR) for Oligometastatic/Oligometastatic Renal Cell Carcinoma

This study is a non-randomized, prospective, registry-based trial that aims to enroll 60 patients with renal cancer who will be diagnosed and treated at our hospital between May 2024 and May 2026. Without altering the patients' systemic treatment plans, those who meet the inclusion criteria after MDT discussion will receive SBRT (Stereotactic Body Radiation Therapy) for all lesions/all metastatic lesions in addition to the guideline-recommended medications. The radiotherapy plan is based on the SABR-COMET protocol and Timmerman's constraints. Patient data will be collected, including general clinical information, toxicity assessments during treatment and in the acute phase, detailed imaging data, regular assessments of pain and quality of life, and evaluations of late radiation therapy responses.

Inclusion criteria

• 1: Patients with newly diagnosed M1 renal cancer or those with oligoprogression during systemic therapy, with no restrictions on the location or number of metastatic sites, but all metastatic sites must be evaluated by the radiation oncology department as safely able to receive a radical radiation dose (α/β value of 3, EQD2 ≥ 70Gy).

2: Age ≥ 18 years. 3: ECOG score of 0-3. 4: Confirmed renal malignancy by pathology or imaging examination, with no subtype restrictions.

5: Presence of evaluable lesions. 6: Patients with spinal cord compression or significant brain metastasis edema requiring surgical decompression can be enrolled after evaluation by the radiation oncology department if the aforementioned dose can be safely administered post-decompression.

7: Able to tolerate radiation therapy and standard systemic therapy (targeted therapy or targeted immunotherapy combination).

8: Expected survival > 6 months. 9: Able to sign the informed consent form. 10: Has conditions for follow-up.

Exclusion criteria

• 1: Patients with other comorbidities that prevent the use or tolerance of targeted immunotherapy drugs, such as targeted immunotherapy drug allergies, active bleeding, ulcers, intestinal perforation, intestinal obstruction, uncontrolled hypertension, grade III-IV cardiac dysfunction (NYHA criteria), severe hepatic and renal insufficiency (grade IV), etc.

2: Patients with other comorbidities that prevent tolerance of radiation therapy.

3: Complete response to first-line drug therapy (i.e., no treatable targets for SABR).

4: Previous history of radiation therapy to the same site. 5: Pregnant or lactating women. 6: Patients with other severe medical comorbidities that prevent participation in the study.