5-Aminolevulinic acid fluorescence in brain non-neoplastic lesions: a systematic review and case series

Fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) is used to assist brain tumor resection, especially for high-grade gliomas but also for low-grade gliomas, metastasis, and meningiomas. With the increasing use of this technique, even to assist biopsies, high-grade glioma-mimicking lesions had misled diagnosis by showing 5-ALA fluorescence in non-neoplastic lesions such as radiation necrosis and inflammatory or infectious disease. Since only isolated reports have been published, we systematically review papers reporting non-neoplastic lesion cases with 5-ALA according with the PRISMA guidelines, present our series, and discuss its pathophysiology. In total, 245 articles were identified and 12 were extracted according to our inclusion criteria. Analyzing 27 patients, high-grade glioma was postulated as preoperative diagnosis in 48% of the cases. Microsurgical resection was performed in 19 cases (70%), while 8 patients were submitted to biopsy (30%). We found 4 positive cases in demyelinating disease (50%), 4 in brain abscess (80%), 1 in neurocysticercosis (33%), 1 in neurotoxoplasmosis, infarction, and hematoma (100%), 4 in inflammatory disease (80%), and 3 in cortical dysplasia (100%). New indications are being considered especially in benign lesion biopsies with assistance of 5-ALA. Using fluorescence as an aid in biopsies may improve procedure time, number of samples, and necessity of intraoperative pathology. Further studies should include this technology to encourage more beneficial uses.