title: Current dosing paradigm for stereotactic radiosurgery alone after surgical resection of brain metastases needs to be optimized for improved local control.
abstract: OBJECTIVE
  To describe the use of radiosurgery (RS) alone to the resection cavity after resection of brain metastases as an alternative to adjuvant whole-brain radiotherapy (WBRT).
  
  
  METHODS
  Sixty-two patients with 64 cavities were treated with linear accelerator-based RS alone to the resection cavity after surgical removal of brain metastases between March 2007 and August 2010. Fifty-two patients (81%) had a gross total resection. Median cavity volume was 8.5 cm(3). Forty-four patients (71%) had a single metastasis. Median marginal and maximum doses were 18 Gy and 20.4 Gy, respectively. Sixty-one cavities (95%) had gross tumor volume to planning target volume expansion of ≥1 mm.
  
  
  RESULTS
  Six-month and 1-year actuarial local recurrence rates were 14% and 22%, respectively, with a median follow-up period of 9.7 months. Six-month and 1-year actuarial distant brain recurrence, total intracranial recurrence, and freedom from WBRT rates were 31% and 51%, 41% and 63%, and 91% and 74%, respectively. The symptomatic cavity radiation necrosis rate was 8%, with 2 patients (3%) undergoing surgery. Of the 11 local failures, 8 were in-field, 1 was marginal, and 2 were both (defined as in-field if ≥90% of recurrence within the prescription isodose and marginal if ≥90% outside of the prescription isodose).
  
  
  CONCLUSIONS
  The high rate of in-field cavity failure suggests that geographic misses with highly conformal RS are not a major contributor to local recurrence. The current dosing regimen derived from Radiation Therapy Oncology Group protocol 90-05 should be optimized in this patient population before any direct comparison with WBRT.
authors.affiliation: Department of Radiation Oncology, Emory University, Atlanta, GA, USA.
authors.forename: Roshan
authors.initials: R
authors.lastname: Prabhu
authors.forename: Hui-Kuo
authors.initials: HK
authors.lastname: Shu
authors.forename: Constantinos
authors.initials: C
authors.lastname: Hadjipanayis
authors.forename: Anees
authors.initials: A
authors.lastname: Dhabaan
authors.forename: William
authors.initials: W
authors.lastname: Hall
authors.forename: Bethwel
authors.initials: B
authors.lastname: Raore
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Olson
authors.forename: Walter
authors.initials: W
authors.lastname: Curran
authors.forename: Nelson
authors.initials: N
authors.lastname: Oyesiku
authors.forename: Ian
authors.initials: I
authors.lastname: Crocker
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology / Q000528:radiation effects; D001932:Brain Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000473:pathology; D009364:Neoplasm Recurrence, Local; D011184:Postoperative Period; D011832:Radiation Injuries / Q000473:pathology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods / Q000592:standards*; D011879:Radiotherapy Dosage / Q000592:standards*; D012189:Retrospective Studies; D017211:Treatment Failure; D047368:Tumor Burden; D055815:Young Adult