Preservation of cognitive function after brain irradiation.

OBJECTIVE: Approximately 50-90% of brain metastatic patients who receive radiation therapy (RT) exhibit cognitive decline which may affects the quality of life of cancer survivors. Hence preservation of cognitive functions in brain metastatic patients becomes important. This review aims to evaluates the pathology or mechanism of cognitive function impairment after brain irradiation and strategies available to preserve cognitive function after radiation therapy. DATA SOURCES: Published articles evaluating the pathology behind radiation induced cognitive impairment and strategies to resolve or preserve cognitive impairment were searched for in scientific databases (eg: PubMed, Scopus, Cochrane database, Google scholar) using keywords including memantine, brain metastases, radiation therapy, pathophysiology, pathogenesis, mechanism and prevention. DATA SUMMARY: Several hypotheses have been offered to explain the mechanism of radiation induced cognitive decline. Among them, vascular hypotheses play a significant role. Some pharmacological agents have been also tested in patients receiving radiotherapy, memantine was found beneficial based with the reference to existing data. CONCLUSION: Future studies are required to evaluate the impact of memantine in different types of radiation therapy procedures and its effects on quality of life of brain metastatic survivors.