The possible role of linac-based stereotactic 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 recurrence of malignant astrocytomas that were consecutively treated by linac-based sterotactic radiotherapy. The patient had previously received multimodalities of treatment for malignant astrocytomas in the right occipital lobe consisting of surgical resection on four occasions, conventional external-beam irradiation, immunological therapy, and systemic chemotherapy. Thereafter she developed relatively small and well-demarcated recurrent lesions in eight different sites, most of which were located in eloquent and deep-seated regions. She underwent ten fractionated linac-based stereotactic radiotherapy courses with a median total dose of 42 Gy, seven fractions of 6 Gy each in 15 days, experiencing neither any adverse effects nor neurologic deterioration. Three out of 10 treated lesions responded well with subsequent reduction in size, 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 clinical results suggest that the fractionated linac-based stereotactic radiotherapy had significant effects on tumor growth inhibition and attainment of acceptable patient performance status.