Shusuke Moriuchi, Kimito Yamada, Makoto Dehara, Yoshifumi Teramoto, Takao Soda, Masami Imakita and Mamoru Taneda
5-Aminolevulinic acid (5-ALA) has been used successfully to resect meningioma without leaving a residual mass. The authors report their experience resecting meningiomas in 17 patients using 5-ALA. Except for one case, all meningiomas fluoresced intra-operatively under the microscope. Invasion to the dura mater, brain parenchyma, or skull showed fluorescence, allowing for confirmation of residual tumor; total removal of the meningioma could be performed more easily, and unexpected neurological deficits could be prevented by precise removal of the tumor under the microscope. With invasion to the dura mater or skull in one case, the extent of dural removal was decided by 5-ALA fluorescence with 1- to 2-cm safety margins. In another case with parenchymal invasion, close removal of the tumor without leaving residual tumor could be performed with 5-ALA fluorescence. With the above methods, no serious side effects or complications occurred in this study. Not all meningiomas fluoresced with 5-ALA, and 5-ALA is available for about 95% of meningiomas. 5-ALA appears easy to use and helpful for finding residual tumor and preventing recurrences by total removal of meningiomas.