Rthp-19. analysis of glioblastoma physical characteristics in patients benefiting from tumor treating electric fields therapy

Tumor treating electric fields (TTFields) are an established treatment for glioblastoma (GBM) patients. However, the anatomical and physical characteristics of the brain and tumor contributing to treatment efficacy are not well understood. We contoured gross tumor volume (GTV) using ScanIP and measured tumor size according to the RANO criteria on 5 patients with recurrent GBMs who exhibited a benefit from TTFields (cohort 1) and 5 who did not show any change (cohort 2). Tumor surface area and geometric centroid distance (GCD) from the bilateral ventricles were computed. Wilcoxon rank sum test was used to compare these physical parameters between the two cohorts. The results showed that the respective median GTV was 11.6 cm3 and 38.1 cm3 (P=0.0591), while the respective median GCD was 5.0 cm and 5.3 cm (P=0.6761), in cohort 1 and 2. The tumor size had a median of 8.2 cm2 in cohort 1, as compared to a median of 53.9 cm2 in cohort 2 (P=0.0591). The surface area had a median of 56.2 cm2 in cohort 1, as compared to a median of 214.0 cm2 in cohort 2 (P=0.4034). After removing an outlier from cohort 1 and another from cohort 2, the respective median GTV was 9.7 cm3 and 41.3 cm3 (P=0.1003), and the respective median surface area was 46.5 cm2 and 236.0 cm2 (P=0.0304). The respective median surface area/GCD was 13.3 cm and 38.9 cm (P=0.0304) and the respective median GTV/GCD was 2.7 cm2 and 8.5 cm2 (P=0.0304). The data suggest that the ratio of surface area/GCD and GTV/GCD, w...
Source: Neuro-Oncology - Category: Cancer & Oncology Authors: Tags: RADIATION THERAPY Source Type: research