Utilizing gemstone spectral CT imaging to evaluate the therapeutic efficacy of radiofrequency ablation in lung cancer.

ABSTRACT

PURPOSE: To evaluate the therapeutic efficacy of radiofrequency ablation (RFA), quantitative water-based, and iodine-based images of gemstone spectral computed tomography (CT) were analyzed. PATIENTS AND 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). CONCLUSION: 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.