Imaging after GliaSite brachytherapy: prognostic MRI indicators of disease control and recurrence.

PURPOSE: In this study, we analyzed the magnetic resonance imaging (MRI) changes in patients after GliaSite treatment and characterized the prognostic MRI indicators in these patients. METHODS AND MATERIALS: A total of 25 patients with recurrent glioblastoma multiforme were treated with the GliaSite Radiation Therapy System. Patients at the Johns Hopkins Hospital with recurrent glioblastoma multiforme underwent surgical resection followed by GliaSite balloon implantation. Available MRI scans for 20 patients were obtained throughout the post-GliaSite treatment course. These were reviewed and analyzed for prognostic significance. RESULTS: After GliaSite treatment, all patients developed some degree of T(1)-weighted contrast and T(2)-weighted hyperintensity around the resection cavity. The development of enhancement on T(1)-weighted contrast-enhanced imaging and the size of these lesions, in the absence of increasing T(2)-weighted hyperintensity, before clinical progression was not associated with decreased survival. Patients with T(1)-weighted enhancement >1 cm had a median survival of 13.6 months and those with T(1)-weighted lesions

Treatment of recurrent glioblastoma multiforme with GliaSite brachytherapy.

PURPOSE: In this study, we assess the efficacy of GliaSite brachytherapy in the treatment of patients with recurrent glioblastoma multiforme (GBM). METHODS AND MATERIALS: Between 1999 and 2004, 24 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 (125)I (Iotrex [sodium 3-((125)I)-iodo-4-hydroxybenzenesulfonate]). Patients at the Johns Hopkins Hospital with recurrent GBM, who were previously treated with surgery and external beam radiotherapy, underwent surgical resection followed by GliaSite balloon implantation. Subsequently, the patients received radiation therapy using the GliaSite to a mean dose of 53.1 Gy. Ten patients were male, and 14 patients were female. The mean age was 48.1 years. All patients had pathologically confirmed recurrent GBM. The median Karnofsky performance status (KPS) was 80. Median follow-up 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 > or =70 had a median survival of 9.3 months, whereas 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 were minor, consisting of mild nausea and/or headache. One patient developed a wound infection. No incidents of meningitis were observed. Late sequelae were rare, but 2 incidents of symptomatic radiation necrosis were observed. One patient developed transient expressive aphasia. 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 > or =70, but only 3.1 months in patients with KPS <70. Favorable survival is observed for patients within each recursive partitioning analysis class. Treatment with GliaSite is safe and generally well tolerated. Additional data are needed to fully assess the therapeutic benefit of GliaSite brachytherapy for recurrent GBM.