gms | German Medical Science

Objective: 5-aminolevulinic acid (5-ALA) guided resection of gliomas in adults, enables better differentiation between tumor and normal brain tissue, allowing a higher degree of resection and improved patient outcomes. In recent years, several reports have emerged regarding the use of 5-ALA for resecting pediatric brains tumors. The aim of the study was to measure the intracellular fluorescence and protoporphyrine IX (PPIX) concentration after admission of 5-ALA.

Methods: Since February 2018 5-ALA was applied orally four hours prior to surgery; during tumor resection the surgeon described the fluorescence signal in strong, weak and no signal. Fluorescence signal and PPIX concertation was measured spectrometrically. In addition, clinical data, imaging and laboratory data was analyzed.

Results: Ten children aged between one and 16 years were operated. Tumor types included: medulloblastoma (2), pilocytic astrocytoma (PA, 2), anaplastic ependymoma (2) and one each of diffuse astrocytoma, anaplastic astrocytoma, pilomyxoid astrocytoma and anaplastic pleomorphic xanthoastrocytoma. Strong fluorescence signals was visible in all anaplastic tumors and one PA, one PA had weak signal. Fluorescence signal correlated with intracellular PPIX intensity (P<.00001) and concentration (P<.0001). Except moderate elevation of liver enzymes no adverse events were reported.

Conclusion: Intraoperative fluorescence signal and spectrometric measurements of tumor tissue are correlated. As in former studies, fluorescence signal was more frequent in malignant glial tumors. No 5-ALA related major adverse events were noticed. Further prospective, controlled trails should be conducted to question feasibility of 5-ALA guided resection of pediatric brain tumors.