PERMANENT I-125 IMPLANTS IN THE UP-FRONT TREATMENT OF MALIGNANT GLIOMAS

BETWEEN JULY 1989 and July 1992, 58 patients with newly diagnosed, his tologically confirmed malignant gliomas (40 anaplastic astrocytomas, 1 8 glioblastoma multiforme) underwent implantation with low-activity io dine-125 sources. Patients were considered appropriate candidates for brachytherapy if their Karnofsky scores were greater than or equal to 70 and their contrast-enhancing tumors were <6 cm in maximum diameter. Tumor volumes ranged from 0.1 to 90 ml. Ten patients had implants onl y. The other 48 patients received additional external beam radiation; 38 patients received radiation 1 to 2 weeks after the implant, and 10 patients received radiation preceding the implant. Median survival has not been reached but is currently greater than 31 months for patients with anaplastic astrocytoma and greater than 23 months for patients w ith glioblastoma. The rate of second operation for this group of patie nts was 45% (26 patients). Brain necrosis requiring resection occurred in 11 patients (19%). Although further follow-up is required, we conc lude that low-activity permanent iodine-125 implants provide patients who have newly diagnosed malignant gliomas long-term survival with an acceptable risk of late complications.