Cerebral Radiation Necrosis

Abstract

Brain radiation necrosis has been recognized as a potential complication of radiation therapy for cancer for at least five decades. Advances in neuro-radiology and histopathology have helped characterize this problem more fully and some therapeutic interventions may help prevent progression of this pathology. This is important in achieving one of the most important goals of cancer care-maintaining quality of life. This review discusses the evolution of our understanding of radiation necrosis, from the first "autopsy-dependent" reports to the current characterization of these lesions with magnetic resonance (MR) and functional imaging. The review is presented in two parts; Part I deals with the definition, incidence and presumed pathogenesis of radiation necrosis. Part II includes diagnosis on the basis of imaging characteristics, (including functional imaging) and biopsy results. Management options are also explored. Radiation necrosis is a very significant complication of radiation treatment of brain cancers and may have a tremendous impact on a patient's quality of life. The early diagnosis of radiation necrosis in patients receiving radiation therapy to the brain has improved with current neuro-imaging modalities and better understanding of its pathophysiology. The development of treatment modalities has been slower, but is nonetheless promising.