Abstract Background: Giant ulcerative breast cancers (>2,000 cc) with active hemorrhage present a critical therapeutic challenge, as conventional radiotherapy carries a high risk of severe toxicity to surrounding organs. Lattice radiotherapy (LRT) delivers spatially fractionated high-dose vertices within a low-dose background, offering the potential to overcome dose constraints. However, rapid tumor regression induced by LRT may render fixed plans unsafe, necessitating adaptive replanning.
