Abstract
Lattice radiotherapy (LRT) is a type of spatially fractionated radiation therapy (SFRT) that enables the delivery of ablative doses to specific internal regions of large tumoral lesions, while surrounding tissues and nearby critical structures receive significantly lower exposure. This technique relies on a spatial distribution strategy that allows dose levels of radiation to be applied within the tumor in a single session or, alternatively, over the course of five sessions. Over time, LRT has gained attention as a promising method for managing large tumors, especially in cases where conventional treatments may pose higher risks or be less effective, offering the benefit of reduced side effects. This report details the case of a 67-year-old patient suffering from metastatic kidney cancer with a large retroperitoneal mass, which led to severe abdominal pain and symptoms from compression of the inferior vena cava. The patient was treated with LRT over five sessions. The intervention led to rapid relief of symptoms and, during follow-up, a noticeable reduction in tumor size was observed, contributing to a clear improvement in the patient's daily functioning and quality of life. This clinical experience emphasizes the potential role of LRT in addressing large, hard-to-treat tumors and suggests that it may be an effective palliative option in advanced cases of kidney cancer.