The Use of 5-aminolevulinic Acid (ALA) as an Intraoperative Tumor Marker for Resection of Pediatric Central Nervous System (CNS) Tumors

Surgery is the cornerstone treatment of most pediatric CNS tumors, including astrocytomas, ependymomas, medulloblastomas, and many other pathologies. In most pediatric CNS tumors, the aim of surgery is maximal tumor resection, while preserving neurological function. Extent of tumor residual has been shown to be a major prognostic factor for progression free survival (PFS), and survival in several malignant and low-grade tumors such as medulloblastomas, ependymomas, and astrocytic tumors. 5-aminolevulinic acid (5-ALA) has been shown to be valuable in intraoperative marking of various cancers. Following oral admission, during surgery, the tumor tissue is illuminated by blue light. Tumor cells tend to metabolize 5-ALA to a porphyrin named protoporhyrin IX (PpIX). PpIX reacts with the blue light and emits a pinky color (- fluorescence). This enables the surgeon to better identify tumor cells and perform a more extensive resection. Over recent years, many studies have proven the efficacy using 5-ALA for resecting various intracranial and spinal tumors, thus achieving a better tumor control. In the suggested study, we propose using the same technique for various pediatric central nervous system tumors. We will focus on the correlation between various pathologies and the fluorescence, trying to deduce the role of 5-ALA in resection of specific pathologies. Also, we will study the safety of 5-ALA use in the pediatric population.