QLIF-25. EFFECT OF TUMOR TREATING FIELDS (TTFIELDS) ON HEALTH-RELATED QUALITY OF LIFE (HRQoL) IN NEWLY DIAGNOSED GLIOBLASTOMA. RESULTS OF THE EF-14 RANDOMIZED PHASE III TRIAL

TTFields is a novel treatment modality using a patient-operated device applying alternating electrical fields, interfering with organelle assembly and mitosis in diving cells. Previously, TTFields has shown to improve both progression-free and overall survival in newly diagnosed glioblastoma. To determine the net clinical benefit, results on HRQoL are also important. Patients completed two validated HRQoL questionnaires (EORTC QLQ-C30 + BN20) at baseline, and every 3 months thereafter. HRQoL over time was assessed for 9 preselected scales: global health, physical, cognitive, role, social and emotional functioning, itchy skin, pain, and weakness of legs. Also deterioration-free survival (DFS) and time to deterioration (TTD) were determined. 639/695 (92%) patients completed at least the baseline HRQoL questionnaires, which dropped to 42% (197/473) after 1 year. Baseline scores were balanced. HRQoL over time did not significantly differ between treatment arms, except for itchy skin, which was worse with TTFields. More TTFields patients reported stable or improved scores on global health status (53% vs. 38%, p=.001), pain (57% vs. 36%, p