NIMG-41. RAPID AND ACCURATE CREATION OF PATIENT-SPECIFIC COMPUTATIONAL MODELS FOR GBM PATIENTS RECEIVING OPTUNE THERAPY WITH CONVENTIONAL IMAGING (T1w/PD)
Abstract BACKGROUND For understanding the electric field distributions in glioblastoma (GBM) patients receiving OptuneTM therapy computational head models are employed. Accurate and fast model creation is of high importance to patient-specific treatment planning for improving efficacy, i.e., for maximizing intensity delivered to the tumor which depends on the tissues’ electric properties (EPs). Traditional model creation relies on time-consuming tissue segmentation and troublesome binary categorization of distinct tumor areas for assigning homogenous EPs. Here, we present a feasibility study of a new approach for fast model creation that uses individually created, heterogeneous EP maps from conventional MRIs. METHODS In a previous animal study we adapted water-content based electrical properties tomography (wEPT) for creating electrical conductivity (σ) maps at 200 kHz, the operating frequency of OptuneTM therapy. This adapted wEPT approach uses a T1w and a PD image to map the tissues’ water-content (WC) with a simple function. Subsequently the σ map is calculated as a function of WC based on Maxwell’s mixture theory. Three patients of the EF-14 trial were selected for calculating WC and σ maps. One patient was chosen to create a computational head model for simulating OptuneTM treatment. RESULTS The wEPT-estimated values of WC and σ in the healthy brain are accurate, homogenous and consistent among patients. Contrary, wEPT-estimates of WC and σ in tumor tissues are very heterogeneous and variable between patients. The patient-specific model with wEPT reveals more detailed current pathways during OptuneTM therapy. CONCLUSIONS The results emphasize the need for individual head model creation, since binary segmentation masks with pre-defined σ values are not recommended for the heterogeneous and variable tumor. The presented approach holds great promise for rapid creation of patient-specific computational models because only conventional MRIs are needed. However, this method needs to be validated and further established with analyzing more patients.