Study of the Abscopal Effect from Ultra-Hypofractionated Radiation and Immune Checkpoint Inhibitors in Metastatic Renal Cell Carcinoma

What this Trial Is About

This research aims to understand the abscopal effect in patients with metastatic renal cell carcinoma mRCC who are receiving immune checkpoint inhibitors ICIs combined with image-guided ultra-hypofractionated radiotherapy IGU. The study focuses on measuring the abscopal response rate ARR one year after IGU and identifying clinical and immunological factors linked to this effect. It is a multicenter observational study conducted from 2025 to 2028, led by Prof. Hiroshi Onishi and managed by Dr. Zhe Chen. Participants receive IGU using stereotactic or similar ultra-hypofractionated radiotherapy techniques, typically delivering 24-30 Gy in 1-3 fractions to selected metastatic lesions, following institutional standards. Patients continue their ICI therapy as determined by their oncologist. There is no randomization or additional treatment beyond standard care. The study includes a one-year follow-up period with imaging assessments and optional blood samples for cytokine analysis. During the study, tumor responses at irradiated and non-irradiated sites are evaluated using CT or MRI at baseline and at 3, 6, 9, and 12 months post-IGU. Clinical status, laboratory tests, and toxicity are monitored throughout. Researchers measure the abscopal response rate at one year, tumor shrinkage rates, overall survival, disease-specific survival, and progression-free survival. Blood samples may be collected to explore immune biomarkers. Data is recorded electronically, and participants are followed for one year to assess outcomes.

Abscopal Effect of Ultra-Hypofractionated Radiation Plus Immunotherapy in Metastatic Renal Cell Carcinoma