AB025. Efficacy of 5-ALA brightness analysis for malignant brain tumor surgery.

Background: For fluorescence-guided neurosurgery, 5-aminolevulinic acid (5-ALA) is widely used for intraoperative tumor visualization. We quantified the brightness of 5-ALA by Image J and report the pathological results of glioma, and non-tumor lesions.

Methods: From 2019 to 2023, we investigated 27 high-grade glioma patients who underwent surgery with 5-ALA. Twenty-three cases of glioblastoma (GBM) and four cases of anaplastic astrocytoma (AA) were examined. The pathological diagnosis was based on the classification of World Health Organization (WHO) 2016. The 5-ALA was administered before surgery, and the 5-ALA brightness was quantified. Other than high-grade glioma, four low-grade gliomas (LGGs), two radiation necrosis, and one inflammation patients were evaluated by Image J.

Results: In GBM, the mean brightness was 134.5±65.4, except for one negative case. AA showed the mean brightness with 180.5±51.6. All LGGs showed negative in the brightness. In two radiation necrosis cases, the mean brightness was 139.5±37.4. In one inflammatory case, the brightness was 239, but after the lesion removed, the adjacent brain parenchyma showed bright, and the border was not clear. In one GBM case, the ventricle was opened, and the brightness difference between the tumor and the ventricular wall was observed.

Conclusions: 5-ALA brightness analysis by Image J would be helpful to distinguish between malignant glioma and LGG, and other non-tumor lesions to support rapid pathological diagnosis. Also, it would be useful to distinguish between the tumor and the ventricle wall. As for radiation necrosis and inflammation, border of the lesion is unclear.