The current status of 5-ALA fluorescence-guided resection of intracranial meningiomas—a critical review

Abstract

Meningiomas are the second most common primary tumors affecting the central nervous system. Surgical treatment can be curative in case of complete resection. 5-aminolevulinic acid (5-ALA) has been established as an intraoperative tool in malignant glioma surgery. A number of studies have tried to outline the merits of 5-ALA for the resection of intracranial meningiomas. In the present paper, we review the existing literature about the application of 5-ALA as an intraoperative tool for the resection of intracranial meningiomas. PubMed was used as the database for search tasks. We included articles published in English without limitations regarding publication date. Tumor fluorescence can occur in benign meningiomas (WHO grade I) as well as in WHO grade II and WHO grade III meningiomas. Most of the reviewed studies report fluorescence of the main tumor mass with high sensitivity and specificity. However, different parts of the same tumor can present with a different fluorescent pattern (heterogenic fluorescence). Quantitative probe fluorescence can be superior, especially in meningiomas with difficult anatomical accessibility. However, only one study was able to consistently correlate resected tissue with histopathological results and nonspecific fluorescence of healthy brain tissue remains a confounder. The use of 5-ALA as a tool to guide resection of intracranial meningiomas remains experimental, especially in cases with tumor recurrence. The principle of intraoperative fluorescence as a real-time method to achieve complete resection is appealing, but the usefulness of 5-ALA is questionable. 5-ALA in intracranial meningioma surgery should only be used in a protocolled prospective and long-term study.

5‐ALA in the management of malignant glioma

“…However, in 25% of cases PpIX fluorescence was also present in the adjacent cortex. Motekallemi et al in their review conclude that FGS is not as reliable for meningioma as it is for GBM. In meningiomas, PpIX fluorescence is usually very heterogeneous and false negatives and false positives occur more frequently than with GBM.…”

Analysis of the surgical benefits of 5-ALA–induced fluorescence in intracranial meningiomas: experience in 204 meningiomas

“…12,20,37,[39][40][41] Recently, the presence of 5-ALA-induced PpIX fluorescence was also observed in intracranial meningiomas. 1,4,5,7,8,10,11,13,16,18,21,22,35,38,42 However, the benefits of PpIX fluorescence in intracranial meningioma surgery had not been systematically analyzed in a large patient series.…”

Thomas J. Dougherty: An Appreciation

“…Use of ALA as a prodrug for PDT effects was pioneered by James Kennedy in Canada and is now an important procedure for cancer control in the US, China and Europe. The ability of ALA to induce fluorescence in neoplastic tissues can be an aid in resection by identifying malignant tissues .…”