Application value of dual-layer spectral detector CT in precise radiotherapy for central lung cancer with atelectasis / 中华放射学杂志

ABSTRACT

Objective:To evaluate the value of dual-layer spectral detector CT (DLSDCT) in precise radiotherapy for central lung cancer (CLC) complicated with atelectasis.Methods:Clinical and imaging data (including DLSDCT, PET-CT, and radiotherapy simulation CT images) of 26 patients with pathologically confirmed CLC accompanied by atelectasis from the Third Affiliated Hospital of Shandong First Medical University and Shandong Cancer Hospital were analyzed retrospectively. There were 21 males and 5 females, aged 36-82 years. Two physicians assessed CLC identifiability on DLSDCT, PET-CT, and simulation localization CT images, respectively, and outlined the gross tumor volume (GTV) and measured GTV values (GTV DLSDCT, GTV PET-CT, GTV CT). Paired-sample Friedman test was used to compare the differences in GTV of the three images, and the SNK test with Bonferroni correction was used for a two-way comparison. The intra-class correlation coefficient (ICC) was used to compare the agreement of measured GTV between 2 physicians. Results:The differentiation rates on PET-CT, DLSDCT, and simulation CT images were 100% (26/26), 80.77% (21/26), and 11.54% (3/26), respectively. The differentiation rate of CLC on DLSDCT images was significantly higher than that on simulation CT images (χ 2=16.06, P<0.001). GTV CT, GTV PET-CT, and GTV DLSDCT measured on simulation localization CT images, PET-CT images, and DLSDCT images were 58.75 (22.57, 86.17) cm 3, 47.34 (18.13, 69.25) cm 3, and 51.40 (18.87, 71.31) cm 3, respectively, with statistically significant differences (χ 2=44.99, P<0.001). Both GTV DLSDCT and GTV PET-CT were significantly smaller than GTV CT (χ 2=4.23, 6.59, Bonferroni corrected P<0.001), and there was no significant difference between GTV DLSDCT and GTV PET-CT (χ 2=2.36, Bonferroni corrected P=0.055). The agreement between the two physicians was good for GTV values measured on both DLSDCT and PET-CT (ICC=0.86, 0.89). Conclusions:On DLSDCT images, most CLC and atelectasis can be identified. Compared to simulation localization CT, the tumor target areas outlined on DLSDCT are closer to PET-CT, and the tumor volumes outlined by different physicians are more consistent.