Tumor Treating Fields in Clinical Practice with Emphasis on PRiDe Registry

Abstract

Glioblastoma (GBM) represents one of the most difficult tumors to treat and patient survival is dismal at the time of tumor recurrence. Surgical resection, radiation, and systemic chemotherapy do not offer a cure but can extend survival in patients with good prognostic factors. The recently FDA-approved Optune device emits medium frequency (200 kHz) alternating electric fields or Tumor Treating Fields (TTFields) that disrupt mitosis of tumor cells. It was demonstrated to have comparable efficacy when compared to standard-of-care chemotherapy treatment for recurrent GBM patients in a randomized phase III trial (EF-11). However, the extent to which this device benefited patients in routine clinical settings was unclear. Therefore, the Patient Registry Dataset (PRiDe) was developed to capture protected health information from 457 patients from 91 neuro-oncology treatment centers in the United States from October 2011 to November 2013. Major findings from analysis of this database included a significantly longer overall survival in PRiDe patients as compared to the TTField monotherapy-treated subjects in EF-11 study, 9.6 months versus 6.6 months, respectively. Favorable prognostic factors included patient treatment compliance ≥75 %, treatment at earlier recurrences, and higher Karnofsky performance status. Patients who failed bevacizumab did not benefit from TTFields as much as patients who were bevacizumab naïve. There were no unexpected adverse events and the most common device-related side effects were skin reactions, heat sensations, and electric sensitivities on the scalp. This chapter will review the available evidence supporting the use of TTFields in neuro-oncology with emphasis on the lessons learned from the use of the device in clinical practice after the 2011 FDA approval.