INNV-11. DELIVERY OF TTFIELDS TO THE INFRATENTORIAL BRAIN USING HFE ARRAYS

Abstract INTRODUCTION Tumor Treating Fields (TTFields) therapy is a noninvasive, locoregional treatment comprising alternating electric fields delivered to the tumor via two pairs of skin-placed transducer arrays. TTFields physically disrupt cancer cell viability through a multimodal mechanism that includes antimitotic and antitumor immune effects. TTFields therapy is FDA-approved for glioblastoma (GBM) and CE marked for WHO grade 4 glioma. While clinically approved array layouts for GBM target supratentorial tumors, TTFields distribution depends on the arrays’ locations and dedicated layouts are needed to target infratentorial tumors. To increase patient comfort, Novocure developed HFE arrays that are thinner and lighter than existing INE arrays. Here, we evaluate innovative HFE array layouts for TTFields delivery to infratentorial tumors at therapeutic intensities (~1 V/cm). METHODS TTFields delivery was simulated using Sim4Life v6.2 in a male computational model. 32 layouts of HFE arrays were placed on the model’s scalp, neck, and scapulae, with one placed at a standard cerebral location. Local Average Field Intensity (LAFI) and Local Minimum Power Density (LMiPD) were calculated in the cerebrum, cerebellum and brainstem. RESULTS Standard cerebral layout provided LAFI of 2.47 V/cm to the cerebrum, while providing 1.50 and 1.10 V/cm to the cerebellum and brainstem, respectively (LMiPD 2.22, 1.34 and 0.64 mW/cm3). Layouts comprising arrays on the scapulae (right and left) paired in cross configuration with arrays on either the temples or forehead, provided LAFI of 1.87-2.17 V/cm (LMiPD 1.05-2.20 mW/cm3) to the cerebrum, while providing 1.64-2.13 V/cm (LMiPD 1.77-2.26 mW/cm3) to the cerebellum and 1.74-1.89 V/cm (LMiPD 2.28-2.89 mW/cm3) to the brainstem. CONCLUSION Lower array placement provides higher levels of field intensity in the cerebellum and brainstem versus standard cerebral layout, while still providing adequate field intensity to the cerebrum. This simulation-based study suggests feasibility of delivering therapeutic TTFields intensities to infratentorial tumors using dedicated HFE array layouts.