Radiotherapy Induced Central Nervous System Toxicity

Radiotherapy is an essential treatment modality for CNS tumors, but it has its own fair share of side effects and toxicities. CNS side effects greatly impair quality of life of patient. Radiation toxicity damages glial oligodendrocytes and glial astrocytes. Radiation induced brain injury can be described into 3 phases. Acute side effects like fatigue, headache, nausea and vomiting etc., usually occur within days to weeks of irradiation. Early delayed side effects occur within 1–6 months and are persistent fatigue, pseudo progression etc. Late side effects include hypothalamus pituitary axis hormonal imbalance, memory and cognitive impairment and radiation necrosis. This chapter explores assessment of these toxicities and dilemmas between radiation necrosis and tumor progression. This chapter also explores techniques to prevent CNS toxicities like hippocampal sparing, or usage of memantine and treatment of CNS toxicities.