10160- COT-18 DIFFERENCES IN 5-ALA FINDINGS AND BRIGHTNESS ON SECOND SURGERY

Abstract We report cases of malignant brain tumor that underwent multiple surgeries, followed by postoperative radiation therapy and chemotherapy, and discuss the 5-ALA findings, changes in brightness, and factors that affect them. We report four cases, (case 1) anaplastic astrocytoma diagnosed by initial surgery, second surgery was done 18 months after, and the diagnosis was radiation necrosis. 5-ALA was negative at first surgery, and strongly positive at second surgery. (case 2) anapestic astrocytoma with 5-ALA negative findings at first surgery, and strongly positive at second surgery. histopathological findings were same. (case 3) Glioblastoma with 5-ALA strongly positive on both surgery, and they were histologically same. (case 4) breast cancer metastasis. 5-ALA brightness were strongly positive on initial and second surgery, and those were histopathologically same. We considered the malignant transformation of the tumor as the reason for the difference in 5-ALA findings, but one case was radiation necrosis, and three cases had the same pathological findings. It is possible that radiation, chemotherapy, etc. may have had some effect on the change in brightness, and we report here, together with a literature review, on factors that lead to differences in 5-ALA positive findings and brightness.