title: Frequency and risk factors of various complications after computed tomography-guided radiofrequency ablation of lung tumors.
abstract: OBJECTIVE
  To retrospectively determine the frequency and risk factors of various side effects and complications after percutaneous computed tomography-guided radiofrequency (RF) ablation of lung tumors.
  
  
  METHODS
  We reviewed and analyzed records of 112 treatment sessions in 57 of our patients (45 men and 12 women) with unresectable lung tumors treated by ablation. Risk factors, including sex, age, tumor diameter, tumor location, history of surgery, presence of pulmonary emphysema, electrode gauge, array diameter, patient position, maximum power output, ablation time, and minimum impedance during ablation, were analyzed using univariate and multivariate analyses.
  
  
  RESULTS
  Total rates of side effects and minor and major complications occurred in 17%, 50%, and 8% of treatment sessions, respectively. Side effects, including pain during ablation (46% of sessions) and pleural effusion (13% of sessions), occurred with RF ablation. Minor complications, including pneumothorax not requiring chest tube drainage (30% of sessions), subcutaneous emphysema (16% of sessions), and hemoptysis (9% of sessions) also occurred after the procedure. Regarding major complications, three patients developed fever >38.5 degrees C; three patients developed abscesses; two patients developed pneumothorax requiring chest tube insertion; and one patient had air embolism and was discharged without neurologic deficit. Univariate and multivariate analyses suggested that a lesion located < or =1 cm of the chest wall was significantly related to pain (p < 0.01, hazard index 5.76). Risk factors for pneumothorax increased significantly with previous pulmonary surgery (p < 0.05, hazard index 6.1) and presence of emphysema (p <0.01, hazard index 13.6).
  
  
  CONCLUSIONS
  The total complication rate for all treatment sessions was 58%, and 25% of patients did not have any complications after RF ablation. Although major complications can occur, RF ablation of lung tumors can be considered a safe and minimally invasive procedure.
authors.affiliation: Department of Radiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Osaka 545-8585, Japan. o-kuma@msic.med.osaka-cu.ac.jp
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Okuma
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Oyama
authors.forename: Masami
authors.initials: M
authors.lastname: Toyoshima
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakamura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000009:adverse effects*; D004067:Digestive System Neoplasms / Q000473:pathology*; D004618:Embolism, Air / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000453:epidemiology; D010996:Pleural Effusion / Q000209:etiology; D011030:Pneumothorax / Q000209:etiology; D011183:Postoperative Complications / Q000453:epidemiology; D015995:Prevalence; D015641:Radiography, Interventional / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D012983:Soft Tissue Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014565:Urogenital Neoplasms / Q000473:pathology*