Survival after resection of brain metastases with white light microscopy versus fluorescence-guidance: A matched cohort analysis of the Metastasys study data

Background: Metastatic brain disease continues to have a dismal prognosis. Previous studies achieved a reduction of local recurrence rates by aggressively resecting the peritumoral zone (supramarginal resection) or using 5-aminolaevulinic acid (5-ALA) fluorescence. The aim of the present study is to assess whether the use of 5-ALA has an impact on local recurrence or survival compared to conventional white light microscopic tumor resection. Materials and Methods: We included consecutive patients who underwent surgical resection of brain metastases. Two groups were compared: In the “white light” group, resection was performed with conventional microscopy. In the 5-ALA group, fluorescence guided peritumoral resection was additionally performed after standard microscopic resection. In-brain recurrence and mortality were compared between groups. Results: N = 175 patients were included in the study. All baseline parameters were similarly distributed with no significant difference between surgical groups. Local in-brain recurrence occurred in 21/175 patients (12%) with a rate of 15/119 (12.6%) in the white light and 6/56 (10.7%) in the 5-ALA group (p = 0.720). The use of 5-ALA influenced neither in-brain recurrence (OR 0.59 [CI = 95% 0.18; 1.99], p = 0.40) nor mortality (OR 0.71 [CI = 95% 0.27; 1.85], p = 0.49). Conclusions: The use of 5-ALA did not result in lower in-brain recurrence or mortality compared to the use of white light microscopy. The most prominent predictors of survival remain favorable preoperative performance status, a low tumor diameter and the absence of multiple cerebral lesions.