Partial irradiation of the brain.

Abstract

Late radiation injury is the main dose-limiting factor for radiotherapy of tumors of the central nervous system (CNS). Clinical experience as well as analyses of complication data, both for brain necrosis and for changes in neuroimaging after radiosurgery, suggest a pronounced volume effect in the brain. However, the relationships of dose and volume to complications after irradiation of lesions in the brain have yet to be quantitatively assessed. The quantification of volume effects and the modeling of normal tissue response to partial organ irradiation of the brain are particularly demanding because of the highly differentiated and complex structure of the brain and the variety of endpoints after radiotherapy for CNS diseases. This article summarizes the existing clinical data that demonstrate a volume effect in the brain and the current state of knowledge regarding the modeling of complications following partial irradiation of the brain.