P17.19.A RESECTION OF BRAIN METASTASES WITH FLUORESCENCE GUIDANCE - COMPARISON BETWEEN SODIUM-FLUORESCEIN AND 5-ALA

Abstract BACKGROUND Complete neurosurgical resection is an integral part of treatment in cancer patients with metastatic brain disease. The distinction between metastatic and healthy brain tissue is of critical importance in this context. Whereas the use of 5-ALA fluorescence has been established for gliomas, reportedly not all metastases enhance with 5-ALA. Therefore, resection using sodium-fluorescein (Na-Fl) may be more helpful to delineate tumors and their margins. MATERIAL AND METHODS We performed a retrospective analysis of resected brain metastases (BM) and use of intraoperative fluorescent agents from 2021 to date. The surgical reports were analyzed whether 5-ALA or Na-Fl was used and if fluorescence was visible using the specific microscope filter. The histopathological findings were then documented. Finally, a chi-square independence test was performed. RESULTS Of 56 patients with BM, Na-Fl was applied in 30 cases, whereas 26 BMs were resected with use of 5-ALA. Following Na-Fl-administration, in 2 of 30 cases, there was no visible fluorescence in the Yellow 560 nm filter (6.7 %), but fluorescence was positive in the remaining 28 metastases (93.3 %). In contrast, 5-ALA induced fluorescence in the Blue 400 nm filter was negative in 11 (42.3 %), positive in 10 (38.5 %). In 5 cases, the fluorescence pattern was not documented (19.2 %). The difference in positive fluorescence between Na-Fl and 5-ALA was statistically significant (p=0.0007). CONCLUSION In intracranial metastases, Na-Fl-induced fluorescence was more frequently observed in contrast to 5-ALA. Na-Fl can therefore be useful in the identification of brain metastases as well as the rapid and cost-effective differentiation of metastatic from healthy brain tissue. Further studies should be carried out to investigate whether use of Na-Fl influences the extent of resection.