Radiation-induced changes in the brain following stereotactic irradiation evaluated by sequential MRI

Abstract

In 216 patients who underwent stereotactic irradiation (STI), MRI was performed 4–12 times for 17–29 months after STI. Frequency of new radiation-induced lesions more than 2 cm in diameter on sequential MRI following STI, and characteristics on sequential MRI findings were investigated. Ten patients displayed new lesions following STI. These patients comprised eight of 208 patients with intracranial neoplasm and two of seven patients with AVM. Lesions appeared 1–12 months after STI. The lesions appeared near primary lesions in nine patients. Contrast-enhancement was seen along the cerebral cortex in three patients. Sequential MRI is effective in detecting radiation-induced lesions following STI.