title: Utilizing gemstone spectral CT imaging to evaluate the therapeutic efficacy of radiofrequency ablation in lung cancer.
abstract: OBJECTIVE
  To evaluate the therapeutic efficacy of radiofrequency ablation (RFA), quantitative water-based, and iodine-based images of gemstone spectral computed tomography (CT) were analyzed.
  
  
  METHODS
  30 patients underwent lung RFAs from March 2012 to March 2013. Through enhanced chest scans, we obtained the tumor size values by conventional CT images, and quantitatively analyzed the densities of iodine and water in lung tumors from water-based and iodine-based material decomposition images.
  
  
  RESULTS
  Tumors in 22 cases increased in size after RFA while there was no detectable change in the remaining 8 cases. Through water-based material decomposition images, the water content in the tumors increased from (1014.76 ± 6.83 mg/mL) to (1022.71 ± 10.16 mg/mL) after RFA, and this difference was significant (t = -2.329, p < 0.05). Through iodine-based material decomposition images, the iodine content in the tumors was 2.49 ± 0.74 mg/mL before RFA. The tumors were mostly or completely necrotized after RFA and the iodine content in the area of necrosis reduced to 0.45 ± 0.29 mg/m (t = 11.072, p = 0.000).
  
  
  CONCLUSIONS
  By comparing the tumor size, water content and iodine content before and after RFA, we can visualize the morphology and metabolic states of the tumors and evaluate the therapeutic efficiency.
authors.affiliation: Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China.
authors.forename: Xiuyi
authors.initials: X
authors.lastname: Zhi
authors.affiliation: Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China.
authors.forename: Baodong
authors.initials: B
authors.lastname: Liu
authors.affiliation: Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China. steven9130@sina.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D005260:Female; D006801:Humans; D017613:Iodine Compounds; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D017613:Iodine Compounds
keywords: Computed tomography; Gemstone spectral imaging; Lung cancer; Radiofrequency ablation