title: Incidence, timing, and treatment of new brain metastases after Gamma Knife surgery for limited brain disease: the case for reducing the use of whole-brain radiation therapy.
abstract: OBJECTIVE
  In this paper, the authors' goal was to analyze the incidence, timing, and treatment of new metastases following initial treatment with 20-Gy Gamma Knife surgery (GKS) alone in patients with limited brain metastases without whole-brain radiation therapy (WBRT).
  
  
  METHODS
  A retrospective analysis of 114 consecutive adults (75 women and 34 men; median age 61 years) with KPS scores of 60 or higher who received GKS for 1-3 brain metastases ≤ 2 cm was performed (median lesion volume 0.35 cm(3)). Five patients lacking follow-up data were excluded from analysis. After treatment, patients underwent MR imaging at 6 weeks and every 3 months thereafter. New metastases were preferentially treated with additional GKS. Indications for WBRT included development of numerous metastases, leptomeningeal disease, or diffuse surgical-site recurrence.
  
  
  RESULTS
  The median overall survival from GKS was 13.8 months. Excluding the 3 patients who died before follow-up imaging, 12 patients (11.3%) experienced local failure at a median of 7.4 months. Fifty-three patients (50%) developed new metastases at a median of 5 months. Six (7%) of 86 instances of new lesions were symptomatic. Most patients (67%) with distant failures were successfully treated using salvage GKS alone. Whole-brain radiotherapy was indicated in 20 patients (18.3%). Thirteen patients (11.9%) died of neurological disease.
  
  
  CONCLUSIONS
  For patients with limited brain metastases and functional independence, 20-Gy GKS provides excellent disease control and high-functioning survival with minimal morbidity. New metastases developed in almost 50% of patients, but additional GKS was extremely effective in controlling disease. Using our algorithm, fewer than 20% of patients required WBRT, and only 12% died of progressive intracranial disease.
authors.affiliation: Department of Radiation Oncology, New York University Langone Medical Center, 530 First Ave, Suite 8R, New York, New York 10016, USA. stephencrush@aol.com.
authors.forename: Stephen
authors.initials: S
authors.lastname: Rush
authors.forename: Robert E
authors.initials: RE
authors.lastname: Elliott
authors.forename: Amr
authors.initials: A
authors.lastname: Morsi
authors.forename: Nisha
authors.initials: N
authors.lastname: Mehta
authors.forename: Jeri
authors.initials: J
authors.lastname: Spriet
authors.forename: Ashwatha
authors.initials: A
authors.lastname: Narayana
authors.forename: Bernadine
authors.initials: B
authors.lastname: Donahue
authors.forename: Erik C
authors.initials: EC
authors.lastname: Parker
authors.forename: John G
authors.initials: JG
authors.lastname: Golfinos
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology / Q000601:surgery*; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary* / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000295:instrumentation; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D016896:Treatment Outcome