Ki67 Index Correlates with Tumoral Volumetry, and 5-ALA Compromised Resection Margins in Glioblastoma

Abstract

Background: Malignant gliomas are the most prevalent primary cerebral tumor. Preoperative imaging plays an important role, and the prognosis is closely related to surgical resection and histomolecular aspects. Our goal was to correlate Ki67 indexes with tumoral volumetry in semiautomatic segmentation on preoperative magnetic resonance images in a 5-ALA assisted resection cohort.Methods: We included initially seventy-eight IDH-wildtype glioblastoma patients with complete preoperative imaging submitted to 5-ALA assisted resections. Clinical, surgical, and histomolecular ndings were also obtained. Preoperative magnetic resonance studies were preprocessed and segmented semiautomatically on VISVA for whole tumor (WT) on 3D FLAIR, enhancing tumor (ET), and necrotic core (NC) on 3D post-gadolinium T1. Edema volumes (ED) were obtained from the subtraction of ET and NC from WT. According to previous studies, we used a 20% cutoff for Ki67 for statistical analysis.Results: Final sample was of 48 patients. Higher Ki-67 indexes correlated positively with higher WT (p = 0,01), ET (p = 0,03) and ED volumes (p = 0,04), with no correlation with NC volumes (p = 0,18). Ki67indexes were also higher in 5-ALA compromised margins (p = 0,01).Conclusions: There is a correlation between Ki67, the metabolically active tumoral volumes, and 5-ALA compromised margins. Tumoral volumetry aspects (WT, ET, and ED), except for NC, correlated directly with Ki67 indexes. Methodological inconsistencies are probably responsible for contradictory literature ndings, and further studies are needed to validate and reproduce these ndings.