title: Microwave ablation of pulmonary malignancies using a novel high-energy antenna system.
abstract: OBJECTIVE
  To evaluate the technical success, safety, and imaging follow-up of malignant pulmonary nodules treated with a novel high-energy percutaneous microwave ablation (MWA) system.
  
  
  METHODS
  Between July 2010 and September 2011, a total of 23 patients, 12 men, mean age 68 (range 30-87) years with 29 pulmonary malignancies of median diameter 19 (range 8-57) mm, underwent computed tomography (CT)-guided MWA with a 16G microwave needle antenna enabling power up to 180 W. Technical success was defined as needle placement in the intended lesion without death or serious injury. Adequacy of ablation was assessed at 24 h on contrast-enhanced CT. Circumferential solid or ground glass opacification >5 mm was used to define an ideal ablation. Local tumor recurrence was assessed at 1, 3, and 6 months after ablation on contrast-enhanced CT.
  
  
  RESULTS
  MWA was technically successful in 93 % (n = 27). Mean ablation duration was 3.6 (range 1-9) min. Ten patients (43 %) developed a pneumothorax as a result of the MWA; only 3 (13 %) required placement of a chest drain. Thirty-day mortality rate was 0 %. The mean hospital stay was 1.5 (range 1-7) days. A total of 22 lesions (75 %) were surrounded by ≥5 mm ground glass or solid opacification after the procedure. At a median follow-up of 6 months, local recurrence was identified in 3 out of 26 lesions, giving a local control rate of 88 %.
  
  
  CONCLUSIONS
  MWA using a high-power antenna of pulmonary malignancies is safe, technically achievable, and enables fast ablation times.
authors.affiliation: Department of Radiology, Churchill Hospital, Old Road, Oxford, OX3 7LJ, United Kingdom.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Little
authors.forename: Daniel
authors.initials: D
authors.lastname: Chung
authors.forename: Philip
authors.initials: P
authors.lastname: Boardman
authors.forename: Fergus V
authors.initials: FV
authors.lastname: Gleeson
authors.forename: Ewan M
authors.initials: EM
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D015641:Radiography, Interventional; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome