title: Treatment of Nonfunctional Pituitary Adenoma Postoperative Remnants: Adjuvant or Delayed Gamma Knife Radiosurgery?
abstract: OBJECTIVE
  It is still not clear whether Gamma Knife radiosurgery (GKRS) for nonfunctional pituitary adenomas should be used as a standard adjuvant postoperative therapy or applied when there is documented progression of the remnant on follow-up magnetic resonance imaging.
  
  
  METHODS
  We performed a retrospective study of patients with nonfunctional pituitary adenomas who underwent primary surgery and GKRS between 2002 and 2015. Patients were divided into 2 groups on the basis of the GKRS indication: adjuvant treatment (GKRS ≤6 months postoperatively) or delayed treatment (GKRS if documented progression occurred on the follow-up magnetic resonance imaging).
  
  
  RESULTS
  Fifty patients were included and grouped based on adjuvant (n = 13) or delayed (n = 37) GKRS following primary surgery. The adjuvant and delayed groups had 10-year actuarial tumor control rates of 92% and 96% (P = 0.408), respectively. The 10-year actuarial endocrinologic control rate was 82% for the adjuvant group and 49% for the delayed group (P = 0.597). None of the patients developed any new neurologic deficit post-GKRS. GKRS-induced complications (intratumoral bleeding and tumoral tissue inflammation) occurred in 6% of the patients, of whom 4% were in the delayed group and 2% in the adjuvant group.
  
  
  CONCLUSIONS
  Adjuvant treatment with GKRS yields the same high long-term tumor control as delayed GKRS. Neither adjuvant nor delayed GKRS induced additional neurologic complications. There is a trend that adjuvant GKRS induces less additional endocrinologic deficits compared with delayed GKRS.
authors.affiliation: Gamma Knife Center, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands; Department of Neurosurgery, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands; Department of Neurosurgery, Utrecht University Medical Center, Utrecht, The Netherlands. Electronic address: z.sadik@etz.nl.
authors.forename: Z H A
authors.initials: ZHA
authors.lastname: Sadik
authors.affiliation: Department of Neurosurgery, Utrecht University Medical Center, Utrecht, The Netherlands.
authors.forename: E H J
authors.initials: EHJ
authors.lastname: Voormolen
authors.affiliation: Department of Neurosurgery, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.
authors.forename: P R A M
authors.initials: PRAM
authors.lastname: Depauw
authors.affiliation: Department of Neurosurgery, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Burhani
authors.affiliation: Department of Internal Medicine, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.
authors.forename: W A
authors.initials: WA
authors.lastname: Nieuwlaat
authors.affiliation: Gamma Knife Center, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands; Department of Neurosurgery, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Verheul
authors.affiliation: Gamma Knife Center, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands; Department of Neurosurgery, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Leenstra
authors.affiliation: Department of Pathology, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Fleischeuer
authors.affiliation: Gamma Knife Center, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.
authors.forename: P E J
authors.initials: PEJ
authors.lastname: Hanssens
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000532:radiotherapy; D010911:Pituitary Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy*; D011182:Postoperative Care / Q000379:methods / Q000639:trends*; D016634:Radiosurgery / Q000379:methods / Q000639:trends*; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies
keywords: Gamma Knife Radiosurgery; Macroadenoma; Nonfunctional pituitary adenoma; Pituitary surgery