30 patients with
pituitary tumors were treated in our unit and followed for 26-45 months. 14 patients had nonsecreting
adenomas, 7 had
acromegaly, 5 had
prolactinomas, 3 had
Cushing's disease. One patient had a
choristoma of the pituitary stalk. The patient with a
choristoma, 7 patients with nonsecreting
adenomas, 4 with
acromegaly, 1
prolactinoma and 3 with
Cushing's disease had been operated by transsphenoidal microsurgery prior to Gamma Knife (GK) treatment. From this group, one patient with a nonsecreting
adenoma and two with
acromegaly had undergone fractional external
radiotherapy after surgery. Stereotactic MRI localization had been used in all cases. All the
tumors showed either a reduction in volume or cessation of growth; 85% of the patients with
acromegaly showed normalization of
growth hormone (GH) levels. Normalization of
ACTH levels occurred in the 3 patients with
Cushing's disease. All the patients with
prolactinomas showed reduction of
prolactin levels but normalization did not occur. However, in 3 cases the
bromocriptine could be withdrawn. Deterioration of vision was not observed. One patient suffered transient
paresis of the third cranial nerve that improved with
steroids.
Panhypopituitarism appeared in one case of
Cushing's disease two years after the treatment. In the remaining cases there were no changes in their previous physiological pituitary function. We conclude that GK radiosurgery in
pituitary tumors is an effective alternative to transsphenoidal microsurgery when compression of surrounding structures does not exist, and it can efficiently replace conventional irradiation.