Related Experiment Video
Updated: Aug 5, 2026
The Clinical Application of Tumor Treating Fields Therapy in Glioblastoma
Published on: April 16, 2019
Safety and feasibility of tumor treating fields initiated before and during radiotherapy for newly diagnosed
Sied Kebir1, Christoph Oster2, Sandeep Sharma2
1Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Division of Clinical Neuro-Oncology, University Medicine Essen, University of Duisburg-Essen, Essen, Germany. sied.kebir@uk-essen.de.
Background:
Tumor Treating Fields improve survival when started after chemoradiotherapy in newly diagnosed glioblastoma, but the safety and feasibility of initiating treatment before and during radiotherapy remain uncertain.
Methods:
PriCoTTF is a prospective, open-label, nonrandomized, multicenter phase I/II trial. Arm A enrolled adults aged 18 to 70 years with newly diagnosed IDH-wildtype glioblastoma or gliosarcoma, Karnofsky Performance Status of at least 60, and planned focal radiotherapy to 60 Gy in 30 fractions. TTFields at 200 kHz were initiated 2 to 4 weeks after surgery and 1 to 2 weeks before radiotherapy. The primary endpoint was protocol-defined treatment-limiting toxicity from TTFields initiation through 4 weeks after radiotherapy.
Results:
Twenty evaluable patients comprised the Arm A feasibility cohort. No protocol-defined treatment-limiting toxicities occurred (0 of 20 patients; exact 95% CI, 0.0%-16.8%). Grade 3 or higher adverse events occurred in 12 patients (60%), predominantly hematologic toxicity attributable to chemoradiotherapy; lymphopenia occurred in 6 patients (30%). Median usage through visit 4 was 76.5%, and median time to first attainment of at least 75% daily use was 2 days. Median progression-free survival was 6.9 months (95% CI, 2.7-14.0), and median overall survival was 18.0 months (95% CI, 12.1-19.9).
Conclusions:
Initiation of TTFields before and during radiotherapy was feasible and was not associated with protocol-defined treatment-limiting toxicity in the Arm A cohort. Because the TLT definition was narrow and efficacy analyses were exploratory and exposure-conditioned, these findings should be interpreted as feasibility data rather than evidence of improved tumor control or survival. The results support randomized evaluation of earlier TTFields integration in newly diagnosed glioblastoma.
Trial Registration:
German Clinical Trials Register DRKS00016667, registered 26 February 2019.
