ACTR-40. STEREOTACTIC RADIOSURGERY AND TUMOR TREATING FIELDS IN SMALL CELL LUNG CANCER PATIENTS WITH LIMITED BRAIN METASTASES: A PILOT AND FEASIBILITY TRIAL

Abstract

BACKGROUND: Small cell lung cancer (SCLC) spreads to the brain in 40% of patients. Historically, whole brain radiation has been used to treat brain metastases. In cases of limited brain metastases from other malignancies, stereotactic radiosurgery (SRS) is supplanting whole brain radiation due to lower rates of neurocognitive toxicity with similar survival. Tumor treating fields (TTFields) are safe and effective in patients with primary brain tumors, and TTFields are being investigated in patients with non-small cell lung cancer brain metastases. The purpose of this single-center trial is to determine the rate of brain relapse in patients with small cell lung cancer metastases treated with SRS and TTFields. STUDY DESIGN: Twenty patients with 1-10 newly diagnosed brain metastases from SCLC will receive SRS followed by TTFields and supportive care. Patients are followed every two months until second cerebral progression. The objectives are to determine the safety and feasibility of SRS and TTFields in this population and to determine the rate of brain relapse. Endpoints are time to first cerebral progression, rate of local brain failure, rate of distant brain failure, rates of toxicity, and neurocognitive and quality of life outcomes using the following instruments: HVLT-R, COWAT, TMT, and EORTC QLQ. Treatment consists of continuous TTFields at 200 kHz applied to the brain within 7 days of SRS. This frequency is based on in vivo data showing the optimum frequency for a SCLC cell line to be 200 kHz. The TTFields unit is a portable device that uses four transducer arrays that are covered by a wig or hat to allow for normal daily activity. Patients receive best standard of care for systemic disease. The trial is designed to assess feasibility, potential toxicity, and efficacy of this treatment approach.