Stereotactic radiosurgery of pituitary adenomas.

The goal of pituitary adenoma radiosurgery is to halt tumor growth, normalize hormonal hypersecretion if present, maintain normal pituitary function, and preserve important structures around the sella. The radiation dose necessary to stop tumor growth is lower than the dose necessary to achieve normalization of hormonal hypersecretion. The minimum distance required between the irradiated target and the optic pathway should be 2 mm for secreting adenomas, but in cases of nonsecreting adenomas this distance is even lower. The current role of radiosurgery in most cases is as an adjuvant treatment of residual or recurrent adenomas after previous microsurgery.