One of the major problems involved in irradiating cancers of the central nervous system is the high rate of long-term side-effects (sequelae). In children, memory deficits, a decline in overall intelligence, and attention disorders occur at times after radiation therapy, depending on the age of the patient, the amount of the brain treated, and the dose of radiation. Some chemotherapy drugs increase the risk of these complications. In adults, these sequelae are less common, but sometimes do occur.
Recent advances in radiation therapy technology allow significantly more precision in the delivery of radiation therapy, allowing higher doses to the cancers while dramatically decreasing the amount of radiation given to normal tissues which may be damaged by the treatment, thus lessening the chances of complications and long-term side-effects.
Conformal radiation therapy, radiosurgery, fractionated stereotactic radiation therapy, and intensity-modulated radiation therapy (IMRT), and proton radiation are all methods of increasing the precision of radiation therapy.