The role of 5-aminolevulinic acid in brain tumor surgery: a systematic review.

Recently, 5-aminolevulinic acid (5-ALA) has been utilized as an adjuvant to the surgical resection of primary brain tumors and metastases. We conducted a systematic review of the literature to further understand the role of 5-ALA in neurosurgery. Our goal was to identify the utility of 5-ALA during resection by evaluating its sensitivity and specificity for different tumor types, as well as the extent of tumor resection achieved while using 5-ALA. A search of the literature was conducted using the PubMed database for the period January 1990 through May 2014. Surgical series in which 5-ALA was used for brain neoplasm resections were evaluated for tumor histology, sensitivity, specificity, extent of resection, complications, and outcomes. Twenty-two series, involving 1163 patients, were included in our review. 5-ALA sensitivity was highest in high-grade gliomas (85 %) and meningiomas (81 %). 5-ALA specificity was high in meningiomas (100 %), as well as metastases (84 %) and high-grade gliomas (82 %). Gross total resection (GTR) was achieved using 5-ALA in 66.2 % of all gliomas and 69.6 % of meningiomas, regardless of histological subtype. 5-ALA may be a useful tool in increasing the extent of resection and achieving GTR in intracranial tumors. The resection of tumors for which 5-ALA has high sensitivity and specificity, such as high-grade gliomas, may lead to an increase in extent of resection when compared to operations using only standard white light. Further evidence for the use of 5-ALA in meningiomas and certain subtypes of metastases may be needed to qualify its efficacy.