Feasibility of Treating High Grade Gliomas in Children with Tumor-Treating Fields: A Case Series

Children diagnosed with high grade gliomas (HGG) have dismal prognoses and treatment options remain limited. Tumor treating fields (TTFields) in combination with temozolomide (TMZ) is approved for the treatment of newly diagnosed and recurrent glioblastoma (GBM) in adult patients. However, clinical experience with TTFields in the pediatric HGG population is lacking. This retrospective review of four clinical cases was undertaken to evaluate the feasibility of treating children diagnosed with HGG off- label with TTFields. Patients were evaluated for device compliance, safety, and outcome. Treatment with TTFields was delivered via four transducer arrays placed on the shaved scalp, which were connected to a portable device generating 200 kHz alternating electric fields. One female and three male patients (ages 4-16 years) with heavily pretreated HGG were treated with TTFields off-label from March 2015 to December 2016. In three of these cases, TTFields were administered in combination with TMZ. Across all four patient cases, average wear compliance rates ranged between 53% and 92%. No device-related toxicities were reported during treatment with TTFields delivered for up to four months. All patients eventually died of the disease. TTFields was well tolerated in our limited cohort of patients. Compliance times were similar to what has been reported in adults without significant toxicity. Further studies of the efficacy and safety of TTFields in children with HGG are underway in a clinical trial setting.