Evaluation of spectral CT in differentiating metastatic from non-metastatic lymph nodes in non-small cell lung cancer(NSCLC)
Abstract Background Lung cancer is the main cause of tumor-correlated deaths, analysis of lymph nodes is crucial to staging of lung cancer. The purpose of the study is to explore the importance of spectral CT imaging in the difference prognostic of metastatic and non-metastatic mediastinal lymph nodes in non-small cell lung cancer. Methods A retrospective examination of 76 patients with non-small cell lung tumor who underwent spectral CT was performed. Quantifiable GSI (Gemstone spectral imaging) parameters (eg, 40 keV, iodine concentration, water concentration) were calculated in non-contrast, arterial and venous phase in 110 mediastinal lymph nodes using AW4.6 (GE HEALTHCARE, USA). Results The CT values of 40 kev, λHU (The slope of Hounsfield unit curve) and IC(values of iodine concentration values), WC(values of water concentration) measured at the arterial or venous phase were not significantly different from those of metastatic growth lymph nodes (P > 0.05). The net value of Arterial phase (nIAP,net value of iodine concentration in Arterial phase) and vein phase (nIVP, net value of iodine concentration in vein phase) were calculated. The value of nIAP was the difference between IAP (iodine concentration of arterial phase) and INCP (iondine concentration of non-contrast phase), while the value of nIVP was the difference between IVP (iodine concentration of venous phase) and INCP. There stood no noteworthy difference in nIAP amid metastatic lymph nodes and non-metastatic lymph nodes (P = 0.110). There was a substantial difference in nIVP amid metastatic lymph nodes and non-metastatic lymph nodes (P = 0.001). Conclusions Compared with qualitative assessment with conventional CT imaging features, quantitative GSI parameters (nIVP) showed higher accuracy for the preoperative diagnosis of mediastal lymph nodal metastases in patients with NSCLC.