title: Local control of newly diagnosed and distally recurrent, low-volume brain metastases with fixed-dose (20 gy) gamma knife radiosurgery.
abstract: BACKGROUND
  Metastases to the brain occur in 20% to 30% of patients with cancer and have been identified on autopsy in as many as 50% of patients.
  
  
  OBJECTIVE
  To analyze the efficacy of 20-Gy Gamma Knife radiosurgery (GKR) as initial treatment in patients with 1 to 3 brain metastases ≤ 2 cm in greatest diameter.
  
  
  METHODS
  A retrospective analysis of 114 consecutive adults with Karnofsky performance status ≥ 60 who received GKR for 1 to 3 brain metastases ≤ 2 cm in size was performed. Five patients lacked detailed follow-up and were excluded, leaving 109 for outcome analysis (34 men and 75 women; median age, 61.2 years). All metastases received 20 Gy to the 50% isodose line.
  
  
  RESULTS
  One hundred nine patients underwent treatment of 164 metastases at initial GKR. Twenty-six patients (23.9%) were alive at last follow-up (median time, 29.9 months; range, 6.6 months to 7.8 years). The median overall survival was 13.8 months (range, 1 day to 7.6 years). Among the 52 patients with distant failure, 33 patients received 20 Gy to 95 new lesions. A total of 259 metastases received 20 Gy, and 4 patients lacked imaging follow-up secondary to death before posttreatment imaging. Local failure occurred in 17 of 255 treated lesions (6.7%), yielding an overall local control rate of 93.3%. Actuarial local control at 6, 12, 24, and 36 months was 96%, 93%, 89%, and 88%, respectively. Permanent neurological complications occurred in 3 patients (2.8%).
  
  
  CONCLUSIONS
  Among patients with 1 to 3 brain metastases ≤ 2 cm in size who have not received whole-brain radiation therapy, GKR with 20 Gy provides high rates of local control with low morbidity and excellent neurological symptom-free survival.
authors.affiliation: Department of Neurosurgery, New York University Langone Medical Center, New York, New York 10016, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Elliott
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Rush
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; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery*; D016634:Radiosurgery / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies