title: μMLC-LINAC radiosurgery for intracranial meningiomas of complex shape.
abstract: BACKGROUND
  We present the long-term results of a consecutive series of patients with meningiomas treated by LINAC-radiosurgery using the micro-multi-leaf collimator technique (μMLC).
  
  
  METHODS
  Between May 2001 and July 2009, 78 patients (m: f = 024:54; median age, 56.8 years; range, 20.1-81 years) with 87 intracranial meningiomas (78 WHO I, seven WHO II, two WHO III) were treated with μMLC-LINAC radiosurgery at our institution, either as a primary or salvage treatment following one or more microsurgical procedures. Fifty-eight of 87 tumors (66.7%) were located in the skull base. The remaining 29 meningiomas (33.3%) were located in the convexity of the brain. The median tumor volume was 4.8 ml (range, 0.2-18.3 ml). The median tumor surface dose, maximal dose, and therapeutic isodose were 12 Gy, 16 Gy, and 75%, respectively.
  
  
  RESULTS
  For retrospective evaluation, we included 70 patients (78 tumors) with a minimum radiological follow-up of 24 months. After a median follow-up of 79.7 months (range, 24.2-109.1 months), 24 patients (34.3%) improved in their clinical status (paresis of N. abducens 18/48, facial paresis 4/8, and hemiparesis 2/9), 41 patients remained stable (58.6%), three patients had treatment-related temporary complaints (4.3%); two patients developed vertigo, and one had a left-sided hemihypesthesia. All complaints recovered completely after steroid medication within 2 weeks. Two patients (2.8%) developed permanent trigeminal neuralgia. Follow-up MR images showed a partial remission in 21 tumors (26.9%) and a stable tumor size in 55 cases (70.5%). Two patients with high-grade meningiomas showed a tumor progression (one WHO II and one WHO III meningioma). At the end of follow-up (July 2010), the actuarial 5- and 9-year progression-free survival after radiosurgery were 98 and 96%, respectively. There was no treatment-related mortality.
  
  
  CONCLUSIONS
  LINAC radiosurgery using a micro multi-leaf collimator for complex shaped intracranial meningiomas is effective yielding a high local tumor control, whereas the treatment-related morbidity remains low.
authors.affiliation: Department of Stereotaxy and Functional Neurosurgery, University Hospital of Cologne, Germany.
authors.forename: Faycal
authors.initials: F
authors.lastname: El Majdoub
authors.forename: Moataz
authors.initials: M
authors.lastname: Elawady
authors.forename: Christian
authors.initials: C
authors.lastname: Bührle
authors.forename: Mustapha
authors.initials: M
authors.lastname: El-Khatib
authors.forename: Mauritius
authors.initials: M
authors.lastname: Hoevels
authors.forename: Harald
authors.initials: H
authors.lastname: Treuer
authors.forename: Rolf-Peter
authors.initials: RP
authors.lastname: Müller
authors.forename: Volker
authors.initials: V
authors.lastname: Sturm
authors.forename: Mohammad
authors.initials: M
authors.lastname: Maarouf
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008579:Meningioma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008866:Microsurgery / Q000295:instrumentation / Q000379:methods; D008875:Middle Aged; D011859:Radiography; D016634:Radiosurgery / Q000379:methods* / Q000401:mortality; D012189:Retrospective Studies; D012886:Skull / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D055815:Young Adult