NCT07058948

Spatially Fractionated Radiotherapy Combined With Immunotherapy for Advanced Solid Tumors

A Phase II Prospective, Open-Label, Single-Arm Study Evaluating the Efficacy and Safety of Spatially Fractionated Radiotherapy Combined With Immunotherapy in Patients With Advanced Solid Tumors

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 30 (estimated)
• Sponsor: Tianjin Medical University Cancer Institute and Hospital · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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.

Detailed description

This Phase II clinical trial investigates the combination of lattice radiation therapy (LRT) and immunotherapy in patients with advanced or metastatic solid tumors. LRT, a spatially fractionated radiotherapy technique, creates alternating high - and low - dose regions within the tumor to enhance local control and reduce toxicity to surrounding tissues. Eligible patients will receive treatment using a medical linear accelerator. Within the largest tumor's gross tumor volume (GTV), 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 edge and a volume ratio of 1% - 10% of the GTV. For a single lesion, the D95 of the GTV will be ≥1 Gy per fraction, and the D95 of the LRT target will be 8 - 12 Gy per fraction, while keeping the single - fraction dose to organs at risk as low as possible. All other irradiated metastases will receive low - dose radiotherapy at 100 - 300 cGy × 5 fractions. Brain and bone metastases will be treated with palliative radiotherapy as per clinical routine and are not included in the low - dose radiotherapy. Immunotherapy will be administered during or within one week after radiotherapy. The study will monitor patients for treatment - related toxicities, immune - related adverse events, and assess treatment efficacy through imaging studies and biomarker analysis. The results will provide insights into the effectiveness and safety of combining LRT with immunotherapy for advanced solid tumors.

Conditions

• Solid Cancers
• Radiotherapy
• Immune Checkpoint Inhibitor
• Lung Cancer

Interventions

Type	Name	Description
RADIATION	lattice radiation therapy	Eligible patients will receive treatment using a medical linear accelerator. Within the largest tumor's gross tumor volume (GTV), 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 edge and a volume ratio of 1% - 10% of the GTV. For a single lesion, the D95 of the GTV will be ≥1 Gy per fraction, and the D95 of the LRT target will be 8 - 12 Gy per fraction, while keeping the single - fraction dose to organs at risk as low as possible. All other irradiated metastases will receive low - dose radiotherapy at 100 - 300 cGy × 5 fractions. Brain and bone metastases will be treated with palliative radiotherapy as per clinical routine and are not included in the low - dose radiotherapy. Immunotherapy will be administered during or within one week after radiotherapy.

Timeline

• Start date: 2025-07-01
• Primary completion: 2026-07-01
• Completion: 2027-07-01
• First posted: 2025-07-10
• Last updated: 2025-07-17

Locations

1 site across 1 country: China