title: Long-term results of gamma knife surgery for growth hormone-producing pituitary adenoma: is the disease difficult to cure?
abstract: OBJECTIVE
  The authors conducted a study to determine the long-term results of gamma knife surgery for residual or recurrent growth hormine (GH)-producing pituitary adenomas and to compare the results with those after treatment of other pituitary adenomas.
  
  
  METHODS
  The series consisted of 67 patients. The mean tumor diameter was 19.2 mm and volume was 5.4 cm3. The mean maximum dose was 35.3 Gy and the mean margin dose was 18.9 Gy. The mean follow-up duration was 63.3 months (range 13-142 months). The tumor resolution rate was 2%, the response rate 68.3%, and the control rate 100%. Growth hormone normalization (GH < 1.0 ng/ml) was found in 4.8%, nearly normal (< 2.0 ng/ml) in 11.9%, significantly decreased (< 5.0 ng/ml) in 23.8%, decreased in 21.4%, unchanged in 21.4%, and increased in 16.7%. Serum insulin-like growth factor (IGF)-1 was significantly decreased (IGF-1 < 400 ng/ml) in 40.7%, decreased in 29.6%, unchanged in 18.5%, and increased in 11.1%, which was almost parallel to the GH changes.
  
  
  CONCLUSIONS
  Gamma knife surgery was effective and safe for the control of tumors; however, normalization of GH and IGF-1 secretion was difficult to achieve in cases with large tumors and low-dose radiation. Gamma knife radiosurgery is thus indicated for small tumors after surgery or medication therapy when a relatively high-dose radiation is required.
authors.affiliation: Radiosurgery Center, Nagoya Kyoritsu Hospital and Gamma Knife Center, Komaki City Hospital, Nagoya, Japan. ttkobayashi@kaikou.or.jp
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Mori
authors.forename: Yukio
authors.initials: Y
authors.lastname: Uchiyama
authors.forename: Yoshihsa
authors.initials: Y
authors.lastname: Kida
authors.forename: Shigeru
authors.initials: S
authors.lastname: Fujitani
mesh_terms: D000236:Adenoma / Q000378:metabolism* / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D019382:Human Growth Hormone / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D017063:Outcome Assessment, Health Care; D047748:Pituitary ACTH Hypersecretion / Q000473:pathology / Q000601:surgery; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000601:surgery*; D015175:Prolactinoma / Q000473:pathology / Q000601:surgery; D016634:Radiosurgery / Q000295:instrumentation*
chemical_list: D019382:Human Growth Hormone