Effectiveness and Safety of Lattice Radiotherapy in Treating Large Volume Tumors: A Systematic Review and Meta-analysis Based on Single-arm Clinical Studies.

Background: Lattice radiotherapy (LRT) is a novel spatially fractionated radiotherapy technique specifically designed to treat large tumors more effectively. By alternating high-dose and low-dose regions within the tumor, LRT generates a highly diverse dose distribution.

Aims: To review recent literature on LRT to determine its therapeutic efficacy, survival outcomes, and adverse event rates in treating large-volume tumors, thereby strengthening the evidence base for clinical application.

Study design: Systematic review and meta-analysis.

Methods: We conducted a meta-analysis of all relevant LRT studies identified in four databases-PubMed, Embase, the Cochrane Library, and Web of Science-from their inception to September 2024. Only full-text articles were considered eligible. This study adhered to the 2020 PRISMA guidelines.

Results: The meta-analysis included seven single-arm studies comprising 187 patients. The pooled 3-month complete response rate and partial response rate were 36.67% and 42.49%, respectively, while the three-month progressive disease rate was 7.10%. The tumor volume was reduced by 48.95%. According to survival analysis, the pooled 6-month overall survival rate was 79.27%, with a median response time of 4.25 months. The pooled rates of mild and moderate-to-severe adverse events were 19.40% and 3.37%, respectively. LRT has demonstrated high local control rates and a favorable safety profile in managing large-volume tumors.

Conclusion: This is the first systematic meta-analysis examining the efficacy and safety of LRT in treating large-volume tumors. Although further high-quality studies are needed for validation, LRT exhibits encouraging efficiency and safety in patients with large solid tumors exceeding 5 cm in diameter.