Faculty Bibliography

Stereotactic radiosurgery is commonly used for selected patients with benign cranial base tumors. The goal of radiosurgery is cessation of tumor growth and preservation of neurological function. Over the last 2 decades, the technique of radiosurgery has evolved due to improved imaging, better radiosurgical devices and software, and the continued analysis of results. In this report, the authors discuss technical concepts and dose selection in skull base radiosurgery.

Stroke is a common cause of death and disability. The role of cellular transplantation to promote functional recovery has been explored. Preclinical studies first established the potential for cultured neuronal cells derived from a teratocarcinoma cell line to be tested for safety and efficacy in the treatment of human stroke. In animal models of stroke that caused reproducible learning and motor deficits, injection of neuronal cells resulted in a return of learning behavior retention time and motor function. In this report the authors review several current concepts for cellular repair, discuss important patient selection and surgical technique issues, and discuss plans for future experiments.

BACKGROUND: Although uncommon, adverse radiation effects (ARE) are a potentially serious side effect of brain stereotactic radiosurgery (SRS). Corticosteroids are used to treat suspected ARE but side effects may be significant after long-term usage. Oral pentoxifylline (Ptx) and vitamin E therapy (VitE) are reported to benefit ARE seen in other organ systems. We treated 11 patients with suspected ARE after SRS with Ptx and VitE. METHODS: To assess the response, edema was measured using fluid-attenuated inversion recovery magnetic resonance imaging (MRI). Edema volumes were calculated by first determining the three maximum measurements in the X, Y, and Z planes of the image with the largest signal change. Volume was plotted over time for each patient that had serial MRI scans available. Two patients had 2 separate radiosurgeries and 2 patients underwent 3. Three patients received adjuvant whole-brain radiation therapy. RESULTS: The time until clinical detection of ARE after SRS varied from 3 to 18 months (median, 8 months). The change in edema volume varied from 59.6 ml in 1 patient (worse edema) to -324.2 ml (improvement). The average change in edema from pre- to post-treatment was -72.3 ml. One patient had more edema despite treatment; this patient was found to have tumor recurrence, and not an ARE. Two patients discontinued Ptx because of persistent nausea and abdominal discomfort. CONCLUSIONS: Ptx and VitE may be of benefit in the management of adverse radiation effects and should be studied further.