title: CT-guided percutaneous microwave ablation of pulmonary malignant tumors.
abstract: BACKGROUND
  Microwave ablation (MWA) of lung tumors is a new approach for local tumor control. The purpose of this retrospective study was to evaluate the preliminary results of safety and efficacy of MWA with a dynamic frequency range (902-928 MHz) and power (10-32 W) for local tumor control of thoracic malignancies.
  
  
  METHODS
  From December 1, 2013 to February 1, 2016, there were total 32 lung tumors among 15 patients (7 men, 8 women, age range 43-82 years, mean 57.8±11.1 years of age) receiving MWA of thoracic neoplasms, including lung adenocarcinoma (n=5), metastatic colorectal cancer (n=7), invasive thymoma (n=1), metastatic uterine leiomyosarcoma (n=1), and metastatic ampullary carcinoma (n=1). Mean tumor size was 13.5 mm (range, 3.0-32.0 mm). The mean sequential ablation during each MWA was 2.3±1.1 times (range, 1-5 times). The outcomes of ablation were evaluated by follow-up computed tomography (CT) scans and the complications were assessed by medical records and CT scan after ablation.
  
  
  RESULTS
  The mean follow-up interval of each tumor was 446.8 days (range, 196-902 days). Local tumor recurrence was found in 5 of the 32 tumors resulting in a local control rate 84.4%. No MWA-related mortality was noted. After MWA, the incidence of pneumothorax was 37.5% (12/32). Only one patient with pneumothorax required air evacuation. Third-degree skin burn adjacent to the entry site occurred in one patient and required debridement and closure with flap.
  
  
  CONCLUSIONS
  After appropriate patient selection, MWA with a dynamic frequency range (902-928 MHz) and power (10-32 W) is an effective and safe procedure for local tumor control of recurrent and metastatic lung tumors.
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Ko
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yee-Fan
authors.initials: YF
authors.lastname: Lee
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yi-Chang
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Ning
authors.initials: N
authors.lastname: Chien
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yu-Sen
authors.initials: YS
authors.lastname: Huang
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yao-Hui
authors.initials: YH
authors.lastname: Tseng
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Jang-Ming
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hsao-Hsun
authors.initials: HH
authors.lastname: Hsu
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan; Department of Traumatology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Jin-Shing
authors.initials: JS
authors.lastname: Chen
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yeun-Chung
authors.initials: YC
authors.lastname: Chang
keywords: Lung neoplasms; microwaves; tomography, X-ray computed