title: Endocrine response after gamma knife-based stereotactic radiosurgery for secretory pituitary adenoma.
abstract: OBJECTIVE
  To examine treatment outcomes of Gamma Knife-based stereotactic radiosurgery (GK-based SRS) for secretory pituitary adenomas.
  
  
  METHODS
  25 patients were treated with GK-based SRS for secretory pituitary adenomas with >or=12 months of follow-up.
  
  
  RESULTS
  For prolactinomas, 2 of 4 patients (50%) showed normalization of serum prolactin at a mean time of 18 months. One of 4 had a >or=50% decrease but still abnormal prolactin levels. For adrenocorticotrophic hormone-secreting tumors, 6 of 12 patients (50%) showed normalization of their endocrine levels at a median of 10 months. An additional 2 (17%) had a >or=50% decrease. For growth hormone-secreting tumors, 4 of 9 patients (44%) showed normalization of endocrine levels at a median time of 30 months. Two patients (22%) had >or=50% lower but abnormal endocrine levels.
  
  
  CONCLUSIONS
  GK-based SRS provides a reasonable rate of endocrine normalization of secretory pituitary adenoma. The time to endocrine response is shorter than reported for fractionated external beam radiotherapy. There is a low risk of optic neuropathy.
authors.affiliation: Department of Radiation Oncology, Walter Reed Army Medical Center, Washington, DC, USA.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Tinnel
authors.forename: Mark A
authors.initials: MA
authors.lastname: Henderson
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Witt
authors.forename: Achilles J
authors.initials: AJ
authors.lastname: Fakiris
authors.forename: Robert M
authors.initials: RM
authors.lastname: Worth
authors.forename: Paul M
authors.initials: PM
authors.lastname: Des Rosiers
authors.forename: James W
authors.initials: JW
authors.lastname: Edmondson
authors.forename: Robert D
authors.initials: RD
authors.lastname: Timmerman
authors.forename: Simon S
authors.initials: SS
authors.lastname: Lo