Because patients with
Cushing's disease have an increased morbidity and an age-corrected mortality, treatment is generally started as soon as possible. The goal of treatment in these patients is to induce remission. Although a variety of treatments are available, pituitary radiation is a good option for aggressive
Cushing's disease that fails to respond to surgery, disease that invades the cavernous sinus, and disease that relapses following an initial remission. Conventional radiation therapy, stereotactic radiosurgery, fractionated stereotactic radiation therapy, and
brachytherapy with
Yttrium-90 (Y 90) and
Gold-198 (Au 198) have been used successfully to treat
ACTH-secreting pituitary adenomas in specialized centers. Conventional
radiation therapy is the most frequently used method of
radiation therapy for
Cushing's disease. Stereotactic radiosurgery may be used as an alternative in patients with
adenomas that are smaller than 30 mm and located at least 3 to 5 mm from the optic chiasm. Fractionated stereotactic radiation therapy is an alternative to radiosurgery while interstitial
pituitary irradiation is an alternative to surgical resection in invasive
tumors.
Hypopituitarism is the most common side effect of
pituitary irradiation. This article will review the role of radiation in the primary and secondary treatment in patients with
Cushing's disease caused by
pituitary adenomas.