Results of interstitial brachytherapy for malignant brain tumors.

We evaluated the efficacy of brachytherapy in patients with malignant brain tumors and assessed the factors associated with longer disease control after treatment. From June 1989 to October 1995, 73 patients were treated with stereotactic brachytherapy with temporary placement of iodine-125 implants. The median age was 52 (range 9-79). Median KPS was 80. There were 48 patients with a glioblastoma multiforme, 13 with an anaplastic astrocytoma, and 12 with other tumors. Of the 67 evaluable patients, 20 underwent brachytherapy as part of the therapy for a newly diagnosed tumor (17 were glioblastomas) and 46 had brachytherapy at the time of progression (28 were glioblastomas). Median survival time for all patients undergoing brachytherapy from diagnosis was 70.3 weeks. Median survival from implant was 39.3 weeks. For patients with an anaplastic astrocytoma, median survival from diagnosis and implant was 158.1 and 36.9 weeks respectively. For patients with a glioblastoma multiforme, median survival from diagnosis and implant was 62.9 and 37.1 weeks respectively. Eleven patients (16%) developed radiation necrosis. Nine patients (13%) developed other complications. Age and histologic diagnosis were significant predictors of survival from diagnosis. Age and KPS were independent predictors of time to failure after implant. Certain characteristics, specifically younger age (<55), and a higher KPS (</=70), appear to be associated with longer survival after brachytherapy. Complications, some of which are life-threatening, can and do occur.