Evaluation of Lung Radiofrequency Ablation with Dual-Energy Computed Tomography: Analysis of Tumor Composition and Lung Perfusion

Objective The aim of this study was to evaluate radiofrequency ablation (RFA) of lung tumors with dual-energy computed tomography while focusing on tumor composition and lung perfusion. Methods The 36 tumors in 25 patients were included. Dual-energy computed tomography was performed before RFA and at 2 days and 1, 3, and 6 months thereafter. The effective atomic number (Z eff) of the tumors before RFA was compared with the Z eff at each follow-up using the paired t test. Lung perfusion was evaluated by iodine map images. When decreased perfusion was suspected after RFA, lung perfusion scintigraphy was performed. Results The mean Z eff of the tumors significantly (P < 0.001) decreased at each follow-up, compared with that before RFA. Lung perfusion in the parenchyma peripheral to the tumors appeared to decrease at 2 days in 9 tumors, which was confirmed by scintigraphy in 7 tumors. Conclusions Dual-energy computed tomography was useful by providing additional information on tumor composition and lung perfusion.