Gamma knife radiosurgery for GH-secreting microadenoma with empty sella.

We report a case of a growth hormone secreting microadenoma associated with empty sella treated by gamma knife radiosurgery and we evaluate the effectiveness of radiosurgery for this lesion. A 58-year-old female complained of an acromegalic appearance for 10 years. Magnetic resonance imaging revealed an enlarged sella floor with a compressed, but slightly enlarged pituitary gland. Serum GH values were 8.52 ng/ml. From these results, we diagnosed the presence of a GH-secreting pituitary microadenoma with empty sella. Stereotactic gamma knife radiosurgery was performed to treat the adenoma. The treatment dose was 30 Gy for the tumour margin (50% isodose). The patient was monitored for 5 years without any reported problem. Serum GH values were gradually decreased to 4.1 and 3.5 ng/ml at 1.6 and 3 years. Serum GH values at 5 years after radiosurgery were 1.8 ng/ml within 2 h after glucose load and serum IGF-1 was normalized. We conclude that gamma knife radiosurgery can be an useful alternative treatment modality for GH-secreting adenoma with empty sella in the selected patients when surgery is contraindicated as the primary treatment.