Summary MR‐guided laser interstitial thermal therapy (LITT) induces distinct zonal histopathological changes in recurrent glioblastoma, including central coagulation necrosis surrounded by a reactive immune cell rim of CD68 + , CD163 + and PD‐L1 + macrophages. Increased CD8 + cytotoxic T‐cell infiltration was observed in the perilesional zone (23.5 cells/mm 2 ) relative to outer dense tumour tissue (19.6 cells/mm 2 ), suggesting that LITT may promote a more immunostimulatory local microenvironment. The perilesional transition zone adjacent to the ablation site showed reduced tumour cellularity and lower proliferative activity (Ki‐67) compared to the outer dense tumour tissue, indicating a gradient of thermal effect on tumour biology. These findings provide the first systematic histopathological and immunohistochemical characterisation of human recurrent glioblastoma tissue following LITT, establishing a framework for future studies combining LITT with immunotherapy.
Nielsen et al. (Mon,) studied this question.