THE POSSIBLE ROLE OF LINAC-BASED STEREOTAXIC RADIOTHERAPY IN THE TREATMENT OF MULTIFOCALLY AND HETEROCHRONOUSLY RECURRENT MALIGNANT ASTROCYTOMAS - A CASE-REPORT

We present a 24-year-old woman with multifocal and heterochronous recu rrence of malignant astrocytomas that were consecutively treated by li nac-based stereotactic radiotherapy. The patient had previously receiv ed multimodalities of treatment for malignant astrocytomas in the righ t occipital lobe consisting of surgical resection on four occasions, c onventional external-beam irradiation, immunological therapy, and syst emic chemotherapy. Thereafter she developed relatively small and well- demarcated recurrent lesions in eight different sites, most of which w ere located in eloquent and deep-seated regions. She underwent ten fra ctionated linac-based stereotactic radiotherapy courses with a median total dose of 42 Gy, seven fractions of 6 Gy each in 15 days, experien cing neither any adverse effects nor neurologic deterioration. Three o ut of 10 treated lesions responded well with subsequent reduction in s ize, and 80% of them did not increase at least for 6 months, although 66.7% of the lesions eventually exhibited enlargement of the enhanced areas, some of which were presumed as radiation necrosis. These clinic al results suggest that the fractionated linac-based stereotactic radi otherapy had significant effects on tumor growth inhibition and attain ment of acceptable patient performance status.