Safety and Efficacy of Lattice Radiotherapy in Voluminous Non-small Cell Lung Cancer

Abstract

Objective Lattice radiotherapy (LRT) is a novel technique of delivering heterogeneous doses of radiation to voluminous tumors not amenable to surgery. Built from the conventional two-dimensional grid, LRT utilizes the power of new technology, three-dimensional radiation allowing the delivery of higher doses of radiation to small spheres, also called vertices, inside bulky tumors while limiting exposure to surrounding healthy tissue. The main goals of the study were the evaluation of tumor response and the overall safety of LRT in this cohort of patients with bulky non-small cell lung cancer. Materials and methods During a seven-year period, 10 patients with non-small cell lung cancer (NSCLC), who presented with bulky, unresectable tumors, were treated using a single fraction of LRT followed by conventionally fractionated radiation. Patients received one initial LRT fraction of 18 Gy in the vertices and 3 Gy in the periphery. After the LRT, all patients continued with conventional radiation: 25 to 29 daily fractions of 1.8 Gy to 2 Gy. Results With a median follow-up of six months (range: one to 71 months), the mean decrease in tumor volume was 42%. The overall survival of the entire group ranged from four to 86 months (mean 22, median 16). There was no mortality related to LRT. No significant acute or chronic toxicity was noted. Conclusion In this small cohort, LRT appears to be a safe and effective modality to treat bulky NSCLC. Further research is needed to establish its efficacy in the management of voluminous NSCLC.