title: Percutaneous radiofrequency ablation of lung neoplasms: initial therapeutic response.
abstract: OBJECTIVE
  To evaluate the feasibility, safety, and initial therapeutic effect of radiofrequency (RF) ablation in the treatment of unresectable malignant lung tumors.
  
  
  METHODS
  Fifty-four lung neoplasms in 31 patients were treated with RF ablation. Thirteen tumors were primary lung cancers and 41 were pulmonary metastases. Tumor sizes ranged from 0.7 to 6.0 cm, with a mean size of 2.7 +/- 1.3 cm. After the RF electrode was placed in the tumor with computed tomographic (CT) fluoroscopic guidance, RF energy was applied. Initial therapeutic response was evaluated by (18) F fluorodeoxyglucose positron emission tomography (FDG-PET) and contrast-enhanced CT. The disappearance of FDG uptake on PET images and tumor enhancement on CT images were considered to indicate complete tumor necrosis. Complete necrosis rates were evaluated according to tumor size and type (primary or secondary lung neoplasm).
  
  
  RESULTS
  RF ablation was technically successful in all lesions. Complete necrosis was achieved in 32 of the 54 tumors (59%) after initial RF session. There was a significant difference in the rate of complete tumor necrosis between tumors 3 cm or less and tumors larger than 3 cm (69% vs. 39%; P <.05). Tumor type did not influence complete necrosis rates. Lung abscesses developed in two patients with large tumors.
  
  
  CONCLUSIONS
  Lung RF ablation is a feasible, relatively safe, and promising treatment for unresectable lung neoplasms. Tumor size is an important factor in achieving complete tumor necrosis.
authors.affiliation: Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Akeboshi
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yamakado
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Nakatsuka
authors.forename: Osamu
authors.initials: O
authors.lastname: Hataji
authors.forename: Osamu
authors.initials: O
authors.lastname: Taguchi
authors.forename: Motoshi
authors.initials: M
authors.lastname: Takao
authors.forename: Kan
authors.initials: K
authors.lastname: Takeda
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage; D004067:Digestive System Neoplasms / Q000473:pathology*; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000473:pathology*; D007472:Iohexol; D007890:Leiomyosarcoma / Q000473:pathology*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery*; D008297:Male; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D014055:Tomography, Emission-Computed / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D007472:Iohexol