title: Gamma Knife radiosurgery for medically and surgically refractory prolactinomas: long-term results.
abstract: BACKGROUND
  Prolactinomas are the most common functioning pituitary adenomas. Dopamine agonists (DA) are generally very effective in treating prolactinomas by inducing tumor volume regression and endocrine remission. A minority of patients do not respond to DA or are intolerant because of side-effects. Microsurgical resection when possible is the next treatment option, but cavernous sinus, dural, or bone involvement may not allow for complete resection.
  
  
  OBJECTIVE
  We reviewed the outcome of patients with medically and surgically refractory prolactinomas treated with Gamma Knife radiosurgery (GKRS) during a 22 years follow-up period.
  
  
  METHODS
  We reviewed the patient database at the University of Virginia Gamma Knife center during a 25-year period (1989-2014), identifying 38 patients having neurosurgical, radiological and endocrine follow-up.
  
  
  RESULTS
  Median age at GKRS treatment was 43 years. Median follow-up was 42.3 months (range 6-207.9). 55.3 % (n = 21) were taking a dopamine agonist at time of GKRS. 63.2 % (n = 24) had cavernous sinus tumor invasion. Endocrine remission (normal serum prolactin off of a dopamine agonist) was achieved in 50 % (n = 19). GKRS induced hypopituitarism occurred in 30.3 % (n = 10). Cavernous sinus involvement was shown to be a significant negative prognosticator of endocrine remission. Taking a dopamine agonist drug at the time of GKRS showed a tendency to decrease the probability for endocrine remission.
  
  
  CONCLUSIONS
  GKRS for refractory prolactinomas can lead to endocrine remission in many patients. Hypopituitarism is the most common side effect of GKRS.
authors.affiliation: Department of Neurological Surgery, University of Virginia, Charlottesville, VA, 22908, USA. orcoheni@tx.technion.ac.il.
authors.forename: Or
authors.initials: O
authors.lastname: Cohen-Inbar
authors.affiliation: Department of Neurological Surgery, University of Virginia, Charlottesville, VA, 22908, USA.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Neurological Surgery, University of Virginia, Charlottesville, VA, 22908, USA.
authors.forename: David
authors.initials: D
authors.lastname: Schlesinger
authors.affiliation: Department of Neurological Surgery, University of Virginia, Charlottesville, VA, 22908, USA.|Department of Medicine, University of Virginia, Charlottesville, VA, USA.
authors.forename: Mary Lee
authors.initials: ML
authors.lastname: Vance
authors.affiliation: Department of Neurological Surgery, University of Virginia, Charlottesville, VA, 22908, USA. jsheehan@virginia.edu.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Sheehan
mesh_terms: D000328:Adult; D018491:Dopamine Agonists / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007018:Hypopituitarism / Q000209:etiology; D008297:Male; D015175:Prolactinoma / Q000188:drug therapy / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D018491:Dopamine Agonists
keywords: Gamma Knife; Pituitary adenoma; Prolactinoma; Radiosurgery