BRACHYTHERAPY FOR RECURRENT MALIGNANT ASTROCYTOMA

Purpose: To assess the efficacy of interstitial brachytherapy in the treatment of patients with recurrent malignant astrocytoma. Methods and Materials: Forty-six patients with recurrent malignant astrocytoma were treated with stereotactic high-activity temporary iodine-125 implants between September, 1986 and October, 1992. All patients had been initially treated for malignant asctrocytoma (44) or low-grade astrocytoma (2) with surgery and external fractionated radiation. The median time between initial diagnosis and recurrence treated with brachytherapy was 12.5 months. Twenty-five patients received chemotherapy prior to brachytherapy. Results: All but four patients have died; median survival time following brachytherapy is 46 weeks; Twelve patients underwent reoperation for radiation necrosis at a median interval of 6.5 months after treatment (26%). Five patients incurred complications directly due to brachytherapy (11%). Forty-four patients are evaluable regarding pattern of failure following brachytherapy. Six of these 44 patients (13.6%) recurred at a distance from the treatment volume (4 in brain and 2 in spinal subarachnoid space). Conclusion: Brachytherapy confers modest but meaningful prolongation of survival in selected patients with recurrent malignant astrocytoma, but complications are significant, reoperation frequently required, and recurrence outside the treatment volume common.