title: Single-Isocenter Frameless Volumetric Modulated Arc Radiosurgery for Multiple Intracranial Metastases.
abstract: BACKGROUND
  Stereotactic radiosurgery (SRS) is a well-accepted treatment for patients with intracranial metastases, but outcomes with volumetric modulated arc radiosurgery (VMAR) are poorly described.
  
  
  OBJECTIVE
  To report our initial clinical experience applying a novel single-isocenter technique to frameless VMAR for simultaneous treatment of multiple intracranial metastases.
  
  
  METHODS
  We performed a retrospective analysis of 15 patients undergoing frameless VMAR for multiple intracranial metastases using a single, centrally located isocenter in the period 2009 and 2011. Of these, 3 patients were treated for progressive or recurrent intracranial disease. A total of 62 metastases (median, 3 per patient; range, 2-13) were treated to a median dose of 20 Gy (range, 15-30 Gy). Three patients were treated with fractionated SRS. Follow-up including clinical examination and magnetic resonance imaging (MRI) occurred every 3 months.
  
  
  RESULTS
  The median follow-up for all patients was 7.1 months (range, 1.1-24.3), with 11 patients (73.3%) followed until death. For the remaining 4 patients alive at the time of analysis, the median follow-up was 19.6 months (range, 9.2-24.3). Local control at 6 and 12 months was 91.7% (95% confidence interval [CI], 84.6%-100.0%) and 81.5% (95% CI, 67.9%-100.0%), respectively. Regional failure was observed in 9 patients (60.0%), and 7 patients (46.7%) received salvage therapy. Overall survival at 6 months was 60.0% (95% CI, 40.3%-88.2%). Grade 3 or higher treatment-related toxicity was not observed. The median total treatment time was 7.2 minutes (range, 2.8-13.2 minutes).
  
  
  CONCLUSIONS
  Single-isocenter, frameless VMAR for multiple intracranial metastases is a promising technique that may provide similar clinical outcomes compared with conventional radiosurgery.
authors: Departments of ‡Radiation Medicine and Applied Sciences and §Surgery, Division of Neurosurgery, Moores University of California San Diego Cancer Center, La Jolla, California; ¶Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut.
authors: Steven K M
authors: SK
authors: Lau
authors: Kaveh
authors: K
authors: Zakeri
authors: Xiao
authors: X
authors: Zhao
authors: Ruben
authors: R
authors: Carmona
authors: Erik
authors: E
authors: Knipprath
authors: Daniel R
authors: DR
authors: Simpson
authors: Sameer K
authors: SK
authors: Nath
authors: Gwe-Ya
authors: GY
authors: Kim
authors: Parag
authors: P
authors: Sanghvi
authors: Jona A
authors: JA
authors: Hattangadi-Gluth
authors: Clark C
authors: CC
authors: Chen
authors: Kevin T
authors: KT
authors: Murphy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000556:secondary* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011874:Radiometry; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D016879:Salvage Therapy; D016019:Survival Analysis; D017211:Treatment Failure; D016896:Treatment Outcome