title: Does tumor type affect local control by radiofrequency ablation in the lungs?
abstract: OBJECTIVE
  : To retrospectively evaluate the effect of tumor type on local control by radiofrequency ablation in the lungs.
  
  
  METHODS
  : This study included 252 lung tumors (mean size, 13.5mm) in 105 patients (73 men and 32 women; mean age, 66.6 years) who underwent radiofrequency ablation with a multitined expandable electrode. Those tumors comprised five tumor types: primary lung cancer (n=35) and pulmonary metastases from colorectal cancer (n=117), lung cancer (n=23), renal cell carcinoma (n=49), and hepatocellular carcinoma (n=28). Local control was evaluated with contrast-enhanced computed tomography. The overall local control rates were estimated as well as those for each tumor type using the Kaplan-Meier analysis. Local control rates for a given tumor type were compared with those for the four other types. Then, multivariate multilevel analysis was performed using the variables of tumor type, tumor size, contact with a vessel or bronchus, and procedure period.
  
  
  RESULTS
  : The overall local control rates were 97%, 86%, 81%, and 76% at 6, 12, 18, and 24 months, respectively. Local control rates varied among the tumor types, and metastatic colorectal cancer showed significantly (P=.023) higher local control rates than those of the four other types. However, multivariate analysis indicated that the relative risk of local progression for a given tumor type was comparable to the risks for the four other types.
  
  
  CONCLUSIONS
  : Tumor type per se did not significantly influence local control.
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Okayama 700-8558, Japan. takaoh@tc4.so-net.ne.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Hiraki
authors.forename: Hideo
authors.initials: H
authors.lastname: Gobara
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Mimura
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Sano
authors.forename: Toshihide
authors.initials: T
authors.lastname: Tsuda
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Iguchi
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Kishi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Matsui
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000628:therapy*; D002292:Carcinoma, Renal Cell / Q000628:therapy*; D017115:Catheter Ablation; D015179:Colorectal Neoplasms / Q000628:therapy*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000628:therapy*; D008113:Liver Neoplasms / Q000628:therapy*; D008175:Lung Neoplasms / Q000556:secondary / Q000628:therapy; D008297:Male; D012189:Retrospective Studies