Radiological Evaluation of Anatomical Extensions of Gliomas Based on White Fiber Tracts: Proposal of a Novel Classification.

Abstract

We speculate on the origin and extensions of gliomas based on our understanding of anatomy of the subcortical network, radiological evaluation and surgical experience. We recently classified the white fibers of the brain into four horizontal and one vertical group. The role of this classification in understanding the origin and spread of gliomas is analyzed. A series of 220 consecutive radiological images of patients with low and high grade gliomas were retrospectively evaluated. The classification discussed was applied to these images to study the location and direction of growth of the gliomas. Our results identify that gliomas arise and spread along a named white fiber tract and displace the adjoining tracts. Gliomas that arose from arcuate fibres either remained limited to a gyrus or extended to the adjacent gyri along the course of the arcuate fibres. Gliomas arising from the LAF spread in the direction of the affected tract. Gliomas arising from the CF tended to involve both the hemispheres and extended across the midline. This radiological evaluation of gliomas correlated well with our proposed anatomical classification of white fibers. Gliomas probably originate in the fiber tract and grow along its extension. The adjoining fiber tracts form a reliable barrier to its spread. The surgical implication of the understanding is outlined in brief here and evaluated in details in part B of this study.