title: Radiosurgery with or without A 2-mm margin for 93 single brain metastases.
abstract: OBJECTIVE
  Retrospective comparison of Linac radiosurgery (RS) in 93 single brain metastases with or without a 2-mm margin.
  
  
  METHODS
  A total of 153 patients had Linac RS (between April 1992 and June 2004), with 139 patients (90.8%) evaluable in June 2005. Sixty-one patients (44%) had extracranial lesions and 65 patients had neurologic symptoms (47%). RS alone: 105 patients (66%); RS +whole brain radiotherapy: 34 patients (24%). Single metastasis: 93/139 patients; classic RS: 42/93 patients; 2-mm margin: 51/93 patients; 30 multiple lesions patients were excluded.
  
  
  METHODS
  15 Mv X-ray Linac, circular minibeams, 8-30 mm, four to six noncoplanar coronal arcs. Isodose was 60-80%; doses were 10-20 Gy.
  
  
  RESULTS
  12 months-13 years; median, 14 months.
  
  
  RESULTS
  Local control (LC) was not improved in 51 margin patients vs. 42 classic RS patients: 1 year: 69.1% and 72.4%. Two-year LC rate: 64% and 54.7%, respectively. Survival: median classic RS: 11.3 months; margin RS, 19 months (p = 0.34) and 1 year, 41.6% and 60.2%, respectively. Margin RS patients had a significantly higher rate of severe parenchymal complications: 19.6% vs. 7.1% (p = 0.02); surgery was necessary in 4 of 51 cases vs. 1 of 42 classic RS cases.
  
  
  CONCLUSIONS
  No increase of 1- and 2-year LC rate in margin RS or survival and median survival: 11.3 vs. 19 months (NS) 2-mm margin associated with more severe parenchymal complications (p = 0.02). This procedure is therefore not recommended. Late CT images and 1-mm margin as recommended by pathologists, use of three-dimensional magnetic resonance imaging and fuzzy method to calculate volumes may yield better results. Stereotactic hypofractionation requires further studies.
authors.affiliation: Department of Neurosurgery, St Anne Hospital, Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Nataf
authors.forename: Michel
authors.initials: M
authors.lastname: Schlienger
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Liu
authors.forename: Jean Noel
authors.initials: JN
authors.lastname: Foulquier
authors.forename: Benoit
authors.initials: B
authors.lastname: Grès
authors.forename: Alexandre
authors.initials: A
authors.lastname: Orthuon
authors.forename: Jean Michel
authors.initials: JM
authors.lastname: Vannetzel
authors.forename: Bernard
authors.initials: B
authors.lastname: Escudier
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Meder
authors.forename: François Xavier
authors.initials: FX
authors.lastname: Roux
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Touboul
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016019:Survival Analysis; D047368:Tumor Burden