title: Does Low-Field Intraoperative Magnetic Resonance Improve the Results of Endoscopic Pituitary Surgery? Experience of the Implementation of a New Device in a Referral Center.
abstract: OBJECTIVE
  To assess the contribution of low-field intraoperative magnetic resonance (iMRI) to endoscopic pituitary surgery.
  
  
  METHODS
  We analyzed a prospective series of patients undergoing endoscopic endonasal surgery for pituitary macroadenomas assisted with a low-field iMRI (PoleStarN30, 0.15 T [Medtronic]). Clinical, radiologic, and surgical variables were analyzed and compared with our fully endoscopic historic cohort operated on without iMRI assistance. A bibliographic review of pituitary surgery assisted with iMRI was conducted.
  
  
  RESULTS
  Thirty patients (57% female; mean age, 55 years) were prospectively analyzed. The most frequent tumor subtype was nonfunctioning macroadenoma (50%). The average Knosp grade was 2.3 and mean tumor size was 18 mm. Surgical and positioning time were 102 and 47 minutes, respectively. Hospital stay and complication rates were similar to our historical cohort for pituitary surgery. Mean follow-up was 10 months. Complete resection (CR) was achieved in 83% of patients. Seven patients (23%) benefited from iMRI assistance and achieved a CR in their surgeries. All patients except 1 experienced hormonal activity remission. iMRI sensitivity and specificity was 0.8 and 1, respectively. Although not statistically significant, CR rates were globally 11.5% superior in iMRI series compared with our historical cohort. This difference was independent of cavernous sinus invasiveness grade (CR rate increased 12.5% for Knosp grade 0-2 and 8.1% for Knosp grade 3-4).
  
  
  CONCLUSIONS
  Low-field iMRI is a useful and safe assistance even in advanced surgical techniques such as endoscopy. Its contribution is limited by the intrinsic features of the tumor. Further randomized studies are required to confirm the cost-effectiveness of iMRI in pituitary surgery.
authors.affiliation: Department of Neurosurgery, Hospital Clínic de Barcelona, Barcelona, Spain. Electronic address: iskender_brave@hotmail.com.
authors.forename: Sergio
authors.initials: S
authors.lastname: García
authors.affiliation: Department of Neurosurgery, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Reyes
authors.affiliation: Department of Neurosurgery, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Roldán
authors.affiliation: Department of Neurosurgery, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Torales
authors.affiliation: Department of Endocrinology, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Halperin
authors.affiliation: Department of Endocrinology, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Felicia
authors.initials: F
authors.lastname: Hanzu
authors.affiliation: Department of Rhinology, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Cristobal
authors.initials: C
authors.lastname: Langdon
authors.affiliation: Department of Rhinology, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Isam
authors.initials: I
authors.lastname: Alobid
authors.affiliation: Department of Neurosurgery, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Enseñat
mesh_terms: D000236:Adenoma / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D019635:Neurosurgical Procedures / Q000379:methods*; D010907:Pituitary Hormones / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D012017:Referral and Consultation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012678:Sensation Disorders / Q000209:etiology / Q000601:surgery; D014794:Visual Fields / Q000502:physiology
chemical_list: D010907:Pituitary Hormones
keywords: Endoscopic; Extent of resection; Intraoperative magnetic resonance; Low field; Macroadenoma; Pituitary