The impact of fluorescence guidance on spinal intradural tumour surgery.

PURPOSE: 5-Aminolevulinic acid (5-ALA)-based fluorescence-guided surgery was shown to be beneficial for cerebral malignant gliomas. Extension of this technique for resection of meningiomas and cerebral metastasis has been recently evaluated. Aim of the present study is to evaluate the impact of fluorescence-guided surgery in spinal tumor surgery.
METHODS: Twenty-six patients with intradural spinal tumors were included in the study. 5-ALA was administered orally prior to the induction of anesthesia. Intraoperative, 440 nm fluorescence was applied after exploration of the tumor and, if positive, periodically during and at the end of resection to detect tumor-infiltrated sites.
RESULTS: Tumors of WHO grade III and IV were found in five patients. In detail intra- or perimedullary metastasis of malignant cerebral gliomas was found including glioblastoma WHO grade IV (n = 2), anaplastic astrocytoma WHO grade III (n = 1), anaplastic oligoastrocytoma WHO grade III (n = 1). In addition, one patient suffered from a spinal drop metastasis of a cerebellar medulloblastoma WHO grade IV. Tumors of WHO grade I were diagnosed in 18 patients: Eight cases of meningioma (two recurrences), six cases of neurinoma, one neurofibroma, two ependymoma and one plexus papilloma. At least, benign pathologies were histologically proven in three patients. All four spinal metastasis of malignant glioma (100 %), seven of eight meningiomas (87.5 %) and one of two ependymoma (50 %) were found to be ALA-positive.
CONCLUSION: The present study demonstrates that spinal intramedullary gliomas and the majority of spinal intradural meningiomas are 5-ALA positive. As a surgical consequence, especially in intramedullary gliomas, the use of 5-ALA fluorescence seems to be beneficial.