title: Efficacy and safety of higher dose stereotactic radiosurgery for functional pituitary adenomas: a preliminary report.
abstract: OBJECTIVE
  Single fraction stereotactic radiosurgery (SRS) is a common adjuvant therapy for hormonally active pituitary adenomas when surgical resection fails to control tumor growth or normalize hypersecretory activity. Marginal doses of 20-24 Gy are used at many centers and here we report our outcome data in patients treated with a higher marginal dose of 35 Gy.
  
  
  METHODS
  Thirty-one patients with secretory pituitary adenomas (adrenocorticotropic hormone, n = 15; growth hormone, n = 13; prolactin, n = 2; thyroid-stimulating hormone, n = 1) were treated with 35 Gy to the 50% isodose line, and had a mean follow-up time of 40.2 months (range = 12-96). All patients were evaluated post-SRS for time to hormonal normalization, time to relapse, as well as incidence and time course of radiation-induced hypopituitarism and cranial neuropathies.
  
  
  RESULTS
  Initial normalization of hypersecretion was achieved in 22 patients (70%) with a median time to remission of 17.7 months. After initial hormonal remission, 7 patients (32%) experienced an endocrine relapse, with a mean time to relapse of 21 months. New endocrine deficiency within any of the five major hormonal axes occurred in 10 patients (32%). One patient (3%) developed new-onset unilateral optic nerve pallor within the temporal field 3 years after SRS. Three patients (10%) reported transient new or increasing frontal headaches of unclear etiology following their procedures.
  
  
  CONCLUSIONS
  Time to endocrine remission was more rapid in patients treated with 35 Gy, as compared to previously reported literature using marginal doses of 20-24 Gy. Rates of endocrine remission and relapse, post-SRS hypopituitarism, and radiation-induced sequelae were not increased following higher dose treatment.
authors: Department of Neurosurgery, Yale University School of Medicine and Yale-New Haven Medical Center, New Haven, Connecticut, USA.
authors: Ryan A
authors: RA
authors: Grant
authors: Department of Neurosurgery, Yale University School of Medicine and Yale-New Haven Medical Center, New Haven, Connecticut, USA.
authors: Margaret
authors: M
authors: Whicker
authors: Section of Endocrinology, Yale University School of Medicine and Yale-New Haven Medical Center, New Haven, Connecticut, USA.
authors: Ranee
authors: R
authors: Lleva
authors: Hofstra North Shore-LIJ School of Medicine, Manhasset, New York, USA.
authors: Jonathan P S
authors: JP
authors: Knisely
authors: Section of Endocrinology, Yale University School of Medicine and Yale-New Haven Medical Center, New Haven, Connecticut, USA.
authors: Silvio E
authors: SE
authors: Inzucchi
authors: Department of Neurosurgery, Yale University School of Medicine and Yale-New Haven Medical Center, New Haven, Connecticut, USA. Electronic address: veronica.chiang@yale.edu.
authors: Veronica L
authors: VL
authors: Chiang
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007018:Hypopituitarism / Q000209:etiology; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D009900:Optic Nerve / Q000528:radiation effects; D010907:Pituitary Hormones / Q000097:blood; D010911:Pituitary Neoplasms / Q000473:pathology / Q000601:surgery*; D011183:Postoperative Complications / Q000097:blood / Q000453:epidemiology; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D010907:Pituitary Hormones
keywords: 35 Gy; Gamma-knife surgery; Optic apparatus; Optic nerves; Pituitary adenoma; Stereotactic radiosurgery