Gamma knife radiosurgery for acromegaly: outcomes after failed transsphenoidal surgery.
OBJECTIVE
This study evaluates the safety and efficacy of gamma knife radiosurgery (GKRS) in patients with a growth hormone-secreting adenoma.


METHODS
A retrospective review of data collected from a prospective database of GKRS patients between January 1988 and September 2006 was performed in patients with acromegaly. Successful endocrine outcome was defined as normalization of the insulin-like growth factor level. Tumor volume was also assessed. At least 18 months of follow-up was available in 95 patients who received radiosurgery during the study period. Mean endocrine follow-up was 57 months (range, 18-168 mo).


RESULTS
Normal insulin-like growth factor levels were achieved in 50 patients (53%) at an average time of 29.8 months after radiosurgery (median, 23.5 mo). A decrease in tumor volume control was achieved in 83 (92%) of 90 patients. Five patients (6%) had no change in tumor volume, and two patients (2%) had an increase in tumor volume. New endocrine deficiencies developed in 32 patients (34%). Four patients developed new-onset partial visual acuity deficits; three of these patients had received previous conventional fractionated radiation therapy.


CONCLUSIONS
GKRS is a complementary treatment for recurrent or residual growth hormone-secreting pituitary adenomas. Although infrequent, tumor growth, new-onset pituitary hormone deficiency, recurrence, and neurological dysfunction require careful clinical, radiological, and endocrinological follow-up.
Jagannathan
Jay
J
Lars Leksell Gamma Knife Center, Department of Neurosurgery, University of Virginia Health Sciences Center, Charlottesville, Virginia, USA.
Sheehan
Jason P
JP
Pouratian
Nader
N
Laws
Edward R
ER
Steiner
Ladislau
L
Vance
Mary L
ML
D000172:Acromegaly / Q000209:etiology / Q000601:surgery*; D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery; D012086:Reoperation; D012189:Retrospective Studies; D017211:Treatment Failure