Spatially Fractionated Radiotherapy Combined With Immunotherapy for Advanced Solid Tumors

Lattice radiation therapy (LRT) is a spatially fractionated radiotherapy technique that creates alternating high - and low - dose areas within a tumor to enhance local control and reduce toxicity to surrounding tissues. This study aims to evaluate the effectiveness and safety of combining LRT with immunotherapy in patients with advanced or metastatic solid tumors, through a Phase II clinical trial. Patients will receive specific - dose irradiation using a medical linear accelerator. Within the GTV of the largest tumor, spheres (0.5 - 3 cm in diameter) will be created as high - dose targets (LRT targets), spaced 2.0 - 5.0 cm apart. The LRT targets must be drawn within the GTV, avoiding blood vessels, with a margin of at least 1 cm from the GTV margin, and a volume ratio of 1% - 10% of the GTV. For a single lesion, the D95 of the GTV will be ≥1 Gy/fraction, and the D95 of the LRT target will be 8 - 12 Gy/fraction, with minimal possible single - fraction doses to organs at risk. All other irradiated metastases will receive low - dose radiotherapy (100 - 300 cGy × 5 fractions), except for brain and bone metastases, which will be treated with palliative radiotherapy as per clinical routine. Immunotherapy will be administered during or within one week after radiotherapy.

NCT Number	NCT07058948
Lead Sponsor	Tianjin Medical University Cancer Institute and Hospital
Conditions	Solid Cancers, Radiotherapy, Immune Checkpoint Inhibitor, Lung Cancer
Enrollment	30 participants
Start Date	2025-07-01
Primary Completion	2026-07-01 (estimated)
Study Completion	2027-07-01 (estimated)
Updated on ClinicalTrials.gov	2026-04-29