Fractionated stereotactic radiotherapy with cis-platinum radiosensitization in the treatment of recurrent, progressive, or persistent malignant astrocytoma

Abstract

External beam irradiation of malignant astrocytoma often provides temporary local tumor control, but dose is limited by potential toxicity to normal brain. Fractionated stereotactic radiotherapy (SRT) provides additional radiation to the tumor with less dose deposition in adjacent normal brain. We administered a potential radiosensitizer, cis-platinum (CDDP), to optimize the therapeutic index. CDDP (40 mg/m2) was given weekly, with SRT once or twice weekly, to 20 patients. One had a partial response, 11 stable disease, and eight progressed despite therapy. Acute toxicities were manageable. Five patients required surgery for tumor progression or radiation necrosis. Median response duration was 18.5 weeks and median survival was 55 weeks. SRT combined with CDDP is safe, with durable responses in some patients. Further investigations to determine optimal SRT and CDDP doses and scheduling are justified.