Eduardo Flores Alvarez
National Autonomous University of Mexico, Mexico
Title: Fractional anisotropy intervals derivatives from the diffusion tensor image in peritumoral region and the association with survival in glioblastoma: evidence using survival and correspondence analysis
Biography
Biography: Eduardo Flores Alvarez
Abstract
Introduction: The Diffusion tensor image (DTI) is leading the analysis of brain lesions, and its derived biomarker the fractional anisotropy (FA) can be related to invasion, infiltration, and extension of brain neoplasms. Aim: We aim to evaluate FA values in three tumor regions of patients with glioblastoma (GB) and its association with intervals of overall survival (OS) using survival and correspondence analyses. Methodology: A retrospective study in 36 patients with GB: 23 (63.9%) males, 4614 y; and 13 (36.1%) females, 5313 y. Patients were followed up for 36 months. We measured DTI-derived FA at edema, enhancing rim and necrosis. To account for the tumor location, we used a four-level MRI-based classification based on the GB involvement of the subventricular zone and cortex. Kaplan-Meier method and the Log-Rank test assessed the survival curves between four subgroups based on tumor location. Correspondence analysis evaluated the association between OS (grouped in 7 six-month intervals) and FA measurements in the tumor regions. Results: Median FA values were higher in the normal brain regions (0.351), followed by peritumoral edema (0.190), enhancing ring (0.116) and necrosis (0.071). Comparisons among FA values among tumor regions showed a significant difference, p<.001. The Kaplan–Meier estimates indicated that the median OS for all patients was 19.3 months; the Log-Rank test to compare differences in the OS curves among subgroups was significant χ2 (3)=8.48, p=0.037. Correspondence analysis showed that a positive association between FA values in the edema region and the survival intervals was significant χ2 (18)=30.996, p=0.029. Conclusions: The alternative multivariate assessment of correspondence analysis might supplement the traditional survival analysis in patients with GB. A close follow-up of the variability of FA in the peritumoral edema region is predictive of the OS within specific six-month interval subgroup. Further studies should focus on a predictive model combining surgical and DTI biomarkers