INNV-13. UNDERSTANDING FACTORS THAT INFLUENCE THE DECISION OF ACCEPTING TUMOR TREATING FIELDS (TTF) THERAPY

BACKGROUND Tumor Treating Fields (TTF) Therapy is an FDA-approved therapy in the first line and recurrent setting for glioblastoma. Despite Phase 3 evidence showing improved survival, it is not uniformly utilized despite its availability. This qualitative prospective study interviewed glioblastoma patients to better understand key driving factors for decision making. METHODS Adult glioblastoma patients who were offered TTF and who signed IRB approved consent were included. Patients participated in a one-time recorded interview with the researchers from the Northwestern University Department of Medical Social Sciences and were asked about factors shaping their decision to use or not use TTF. RESULTS 40 patients were enrolled with a mean age of 53 years, 92.5% were white and 60% were male. Of the 33 (82.5%) participants who accepted TTF, 23 (69.7%) reported their physician recommending TTF, 8 (24.2%) reported physician neutrality toward TTF, and 2 (6.1%) said their physician advised against TTF. Among the 7 (17.5%) participants who did not choose TTF, 4 (57.1%) reported physician neutrality, 2 (28.6%) reported that their physician advised against TTF, and 1 (14.3%) reported that their physician recommended TTF. Participants who decided against TTF stated that head shaving, appearing sick, and inconvenience of wearing/carrying the device most influenced their decision. For those choosing to use TTF, the most influential factors were extending life and following their doctor's opinion; other factors included level of familial support and the clinical evidence supporting TTF. DISCUSSION This clinical study was a collaboration with the Medical Social Sciences team to better understand the key factors that drive patient decision making with TTF. Findings suggest that physician support and positive Phase 3 results are among the key decision-making factors. Properly understanding the path to patients’ decision making is crucial in optimizing use of TTF and other therapeutic decisions for glioblastoma patients.