FRACTIONATED STEREOTAXIC RADIOTHERAPY WITH CISPLATINUM RADIOSENSITIZATION IN THE TREATMENT OF RECURRENT, PROGRESSIVE, OR PERSISTENT MALIGNANT ASTROCYTOMA

External beam irradiation of malignant astrocytoma often provides temp orary local tumor control, but dose is limited by potential toxicity t o normal brain. Fractionated stereotactic radiotherapy (SRT) provides additional radiation to the tumor with less dose deposition in adjacen t normal brain. We administered a potential radiosensitizer, cis-plati num (CDDP), to optimize the therapeutic index. CDDP (40 mg/m(2)) was g iven weekly, with SRT once or twice weekly, to 20 patients. One had a partial response, I I stable disease, and eight progressed despite the rapy. 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 CD DP is safe, with durable responses in some patients. Further investiga tions to determine optimal SRT and CDDP doses and scheduling are justi fied.