Treatment of recurrent glioblastoma multiforme with GliaSite brachytherapy

Abstract

1544 Background: Glioblastoma multiforme is a primary malignancy of the central nervous system that is fatal despite treatment with surgery and standard adjuvant therapy. Long-term control of these tumors is rarely achieved and GBM frequently recurs. In this study, we assess the efficacy of GliaSite brachytherapy in the treatment of patients with recurrent glioblastoma multiforme (GBM). Methods: Between 1999 and 2004, twenty-four patients with recurrent glioblastoma multiforme were treated with the GliaSite Radiation Therapy System (RTS). The GliaSite is an inflatable balloon catheter that is placed in the resection cavity at the time of surgical resection. Low-dose rate radiation is then delivered locally by temporarily inflating the balloon with an aqueous solution of organically bound I-125 (Iotrex [sodium 3-(I-125)-iodo-4-hydroxybenzenesulfonate]). Patients at the Johns Hopkins Hospital with recurrent GBM underwent surgical reresection followed by GliaSite balloon implantation. Subsequently, the patients received radiation therapy using the GliaSite to a mean dose of 53.1 Gy. The mean age was 48.1 years. The median Karnofsky performance status (KPS) was 80. Median followup time was 21.8 months. Results: At the time of analysis, 18 patients (75%) had died; 6 patients (25%) were alive. Median survival from diagnosis for all patients was 23.3 months. Median survival after GliaSite brachytherapy was 9.1 months. Patients with a KPS ≥ 70 had a median survival of 9.3 months while patients with a KPS < 70 had a median survival of 3.1 months (p<0.003). Survival was not significantly different between patients receiving 45 Gy and patients receiving a dose greater than 45 Gy. Acute side effects and late sequelae were rare. Conclusions: GliaSite radiotherapy confers a prolongation of survival in patients with recurrent glioblastoma multiforme compared to historical controls with recurrent GBM. GliaSite therapy leads to a favorable survival outcome of 9.3 months in patients with KPS ≥ 70, but only 3.1 months in patients with KPS < 70. Favorable survival is observed for patients within each recursive partitioning analysis (RPA) class. Treatment with GliaSite is safe and generally well tolerated. No significant financial relationships to disclose.