ABSTRACT
Objective:To analyze the value of dual energy CT parameters combined with serum procollagen Ⅰ N-terminal propeptide (PⅠNP) and beta C-terminal cross-linked telopeptide of type Ⅰ collagen (β-CTX) in differential diagnosis of spinal bone metastasis from lung cancer and myeloma.Methods:The clinical data of 54 patients with spinal bone metastasis from lung cancer and 50 patients with myeloma in Jincheng People′s Hospital from October 2019 to March 2021 were analyzed retrospectively. All patients were examined by dual energy CT on the day of admission, and the CT values at the energy levels of 40 to 80 keV (energy interval of 10 keV) were recorded. The serum PⅠNP and β-CTX levels were detected by chemiluminescent assay before treatment. The pathological examination results were taken as gold standard, and the CT values at the energy levels of 40 to 80 keV by dual energy CT and serum PⅠNP and β-CTX levels were compared between 2 groups. Receiver operating characteristic (ROC) curve was used to analyze the differential diagnosis value of the CT values at the energy levels of 40 to 80 keV, serum PⅠNP and β-CTX levels alone and combination.Results:The CT values at the energy levels of 40 to 80 keV by dual energy CT and serum PⅠNP and β-CTX levels in patients with spinal bone metastasis from lung cancer were significantly higher than those in patients with myeloma: 79.86 (61.20, 116.32) HU vs. 58.29 (46.92, 64.03) HU, 64.48 (50.27, 90.08) HU vs. 45.78 (38.59, 56.75) HU, 57.35 (43.31, 78.04) HU vs. 43.62 (36.91, 54.06) HU, 52.05 (42.98, 75.79) HU vs. 41.26 (32.84, 51.76) HU, 45.52 (38.55, 63.59) HU vs. 36.68 (28.72, 49.83) HU, 66.35 (31.15, 81.97) μg/L vs. 31.38 (27.76, 34.50) μg/L and 0.61 (0.48, 0.67) μg/L vs. 0.49 (0.47, 0.52) μg/L, and there were statistical differences ( P<0.05 or <0.01). ROC curve analysis result showed that the sensitivity of the combination of the CT values at the energy levels of 40 to 80 keV by dual energy CT was higher than those alone (83.33% vs. 59.26%, 61.11%, 62.96%, 64.81% and 66.67), the area under the curve (AUC) was also higher than those alone (0.882 vs. 0.798, 0.811, 0.817, 0.801 and 0.773), and there were statistical differences ( P<0.01 or <0.05); the sensitivity of the combination of serum PⅠNP and β-CTX levels was higher than those alone (81.48% vs. 57.41% and 62.96%), the AUC was higher than those alone (0.829 vs. 0.753 and 0.729), and there were statistical differences ( P<0.01 or <0.05); the sensitivity of all indexes combined in the differential diagnosis of spinal bone metastasis from lung cancer and myeloma was higher than those of the combination of the CT values at the energy levels of 40 to 80 keV by dual energy CT, the combination of serum PⅠNP and β-CTX levels (98.15% vs. 83.33% and 81.48%), the same as AUC (0.976 vs. 0.882 and 0.829), and there were statistical differences ( P<0.01); there were no significant differences in the specificity of each index alone and combination ( P>0.05). Conclusions:Compared with myeloma, the CT values at the energy levels of 40 to 80 keV by dual energy CT, serum PⅠNP and β-CTX levels in patients with spinal bone metastasis from lung cancer are increased, and the combination of the above indexes has ideal value in differential diagnosis of the two diseases.