title: Gamma knife radiosurgery for clinically persistent acromegaly.
abstract: Gamma knife radiosurgery (GKRS) is an important additional strategy for unresected clinically active pituitary adenomas. Radiosurgery for acromegaly aims to achieve tumor growth control and endocrine remission, potentially obviating the need for lifetime medication suppression therapy. Forty patients with clinically active acromegaly underwent GKRS between 1988 and 2009. Thirty-four patients had undergone prior surgical resection. The median follow-up interval was 72 months (range 24-145). Endocrine remission was defined as growth hormones (GH) level <2.5 ng/ml and a normal insulin-like growth factor 1 (IGF-1) level (age and sex adjusted) off growth hormone inhibiting drugs for at least 3 months. Endocrine control was defined as normal GH and IGF-1 levels on suppression medication. Endocrine remission was achieved in 19 (47.5 %) patients and endocrine control in four additional (10.0 %) patients. Patients with lower IGF-1 level and with tumors that were less invasive of the cavernous sinus before GKRS were associated with better GH remission rates. Imaging-defined local tumor control was achieved in 39 (97.5 %) patients (27 had tumor regression). One patient with delayed tumor progression underwent a second GKRS procedure. Three other patients had repeat GKRS because of persistently elevated and clinically symptomatic GH and IGF-1 levels. Sixteen (40.0 %) patients eventually developed a new pituitary axis deficiency at a median onset of 36 months after radiosurgery. No patient developed new visual dysfunction. Gamma knife radiosurgery, which is most often applied in clinically symptomatic acromegaly persistent after initial microsurgery, was most effective when the tumor was less invasive of the cavernous sinus and when patients had lower IGF-1 levels before GKRS. Almost one half of the patients no longer required long term medication suppression.
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh School of Medicine, University of Pittsburgh, Suite B-400, UPMC Presbyterian, 200 Lothrop Street, Pittsburgh, PA, 15213, USA.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Liu
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kano
authors.forename: Douglas
authors.initials: D
authors.lastname: Kondziolka
authors.forename: Kyung-Jae
authors.initials: KJ
authors.lastname: Park
authors.forename: Aditya
authors.initials: A
authors.lastname: Iyer
authors.forename: Ajay
authors.initials: A
authors.lastname: Niranjan
authors.forename: John C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
mesh_terms: D000172:Acromegaly / Q000378:metabolism / Q000401:mortality* / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D019382:Human Growth Hormone / Q000378:metabolism; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016634:Radiosurgery; D012074:Remission Induction; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
chemical_list: D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I