title: Gamma knife stereotactic radiosurgery for acromegaly.
abstract: BACKGROUND
  Gamma knife radiosurgery (GKR) is an adjuvant treatment for acromegaly if surgery fails to normalize GH hypersecretion.
  
  
  OBJECTIVE
  To examine the effect of GKR on tumor growth and hypersecretion, and to characterize the adverse effect of this treatment.
  
  
  METHODS
  Cross-sectional follow-up study. First, retrospective data pre- and post-GKR were collected. PATIENTS then underwent a predefined survey including radiological, endocrinological, ophthalmological, and neurosurgical evaluation.
  
  
  METHODS
  Norwegian National Center for gamma knife treatment.
  
  
  METHODS
  Sixty-one patients treated with GKR for acromegaly. Out of 55, 53 living patients underwent a detailed survey. The mean follow-up was 5.5 years. No patient was lost to follow-up.
  
  
  RESULTS
  Tumor growth was stopped in all patients. At 3, 5, and 10 years after GKR, 45, 58, and 86% of patients had normal IGF-I levels. Consecutive hormone value analysis showed that patients receiving GH-suppressive medication had a more rapid decline in hypersecretion than those who did not receive such medication. Evaluated by survey baseline values alone, non-elevated IGF-I and GH levels below 5 mIU/l were found in 38%. GH-suppressive medication was terminated in 16 out of 40 patients following GKR. Nine out of 53 surveyed patients (17%) had normal IGF-I and GH nadir below 2.6 mIU/l at glucose tolerance tests, while not on hormone-suppressive medication. Two patients developed minor visual field defects. Eight patients started hormone substitution therapy during the follow-up period.
  
  
  CONCLUSIONS
  GKR is an effective adjuvant treatment for residual acromegaly, carrying few side effects.
authors.affiliation: Department of Neurosurgery, Haukeland University Hospital, Bergen, Norway. e.o.vik-mo@medisin.uio.no
authors.forename: Einar Osland
authors.initials: EO
authors.lastname: Vik-Mo
authors.forename: Marianne
authors.initials: M
authors.lastname: Oksnes
authors.forename: Paal-Henning
authors.initials: PH
authors.lastname: Pedersen
authors.forename: Tore
authors.initials: T
authors.lastname: Wentzel-Larsen
authors.forename: Eyvind
authors.initials: E
authors.lastname: Rødahl
authors.forename: Frits
authors.initials: F
authors.lastname: Thorsen
authors.forename: Thomas
authors.initials: T
authors.lastname: Schreiner
authors.forename: Sylvi
authors.initials: S
authors.lastname: Aanderud
authors.forename: Morten
authors.initials: M
authors.lastname: Lund-Johansen
mesh_terms: D000172:Acromegaly / Q000401:mortality / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007018:Hypopituitarism / Q000209:etiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D010911:Pituitary Neoplasms / Q000401:mortality / Q000601:surgery*; D011183:Postoperative Complications / Q000401:mortality*; D016634:Radiosurgery / Q000009:adverse effects* / Q000401:mortality; D012189:Retrospective Studies; D014786:Vision Disorders / Q000209:etiology / Q000401:mortality