Visual Mapping for Tumor Resection: A Proof of Concept of a New Intraoperative Task and A Systematic Review of the Literature

Abstract

Homonymous hemianopia has been reported after brain tumor resection with a significant effect on quality of life. Nevertheless, no standardized methods exist for intraoperative optical radiation mapping. The purpose of this article is to describe a new intraoperative task for visual mapping and to review the existing literature. A Central and Peripheral Image task was used to map optic radiations during brain tumor resection in 3 patients. A systematic review was performed following PRISMA 2020 guidelines, with 25 of 449 articles included. Optic radiations were identified in all patients and preserved in all but one, in whom the extent of resection prevailed. The literature review exposed 2 methods to assess visual function: visual evoked potentials (VEP) and direct electric stimulation (DES), with 13 and 12 articles and 341 and 63 patients, respectively. Hemianopia was developed in 13.49% of patients with VEP versus 1.59% of patients with DES. The use of DES might be associated with a better outcome (level IV evidence). However, standardization of intraoperative tasks during DES could be improved. In this context, the Central and Peripheral Image task might be an adequate tool for the resection of tumors affecting the optic radiations.