Medical therapy is available for some hypersecretory tumors (35,37,44,45). Most prolactin secreting adenomas are effectively treated with dopamine agonists (eg. bromocriptine, cabergoline). Surgical intervention is reserved for those who are intolerant of medical therapy, whose prolactin levels remain elevated or whose tumors continue to grow despite maximal medical treatment.

Medical treatment using somatostatin analogues or dopamine agonists has varying degrees of efficacy for treating GH adenomas. The recently described growth hormone receptor anatagonist, pegvisamont, may prove more effective (38). Currently, medical therapy is reserved for those patients awaiting surgery or those with persistent disease postoperatively. There is some evidence that pre-surgical medical therapy may improve surgical outcome (29).

Ketoconazole and/or metyrapone therapy can normalize serum cortisol levels in patients with Cushing's disease preoperatively. Like acromegaly, surgery remains the first-line therapy. The disadvantage of medical treatment of hypersecretory syndromes is that it is suppressive in nature. Tumors often recur when medications are discontinued.

Radiotherapy is most often employed in conjunction with medical or surgical therapy. Fractionated external beam radiation therapy reduces excessive hormone production and can reduce the incidence of tumor recurrence (50). Gamma knife or linear accelerator stereotactic radiosurgery is increasingly applied to pituitary tumors and is also effective in normalizing hormonal hypersecretion and preventing recurrence (17,18,26,27). Whether by fractionated external beam or radiosurgery, the effects of radiotherapy are delayed. Patients require continued suppressive medical therapy during the period between treatment and effect. There is also a significant incidence of radiation-induced delayed panhypopituitarism (3,8,49,50).