Early diagnostic value of ECT whole-body bone imaging combined with PINP and β-CTX for bone metastasis of lung cancer.

Objective: This research was aimed at investigating the early diagnostic value of emission computed tomograph (ECT) whole-body bone imaging combined with PINP and β-CTX for bone metastasis of lung cancer.

Methods: Case data of 86 lung cancer patients were categorized into lung cancer with bone metastasis (LCWBM, 46 cases) and lung cancer without bone metastasis (LCWOBM, 40 cases) groups according to the presence or absence of bone metastasis. Patients' general information were collected. ECT whole-body bone imaging was used to detect bone metastases and the grading of the extent of disease (EOD) in both groups, and electrochemiluminescence was utilized to detect the serum levels of PINP and β-CTX. Spearman correlation analysis was employed to evaluate the correlation between EOD grading and PINP and β-CTX levels. Logistic univariate and multivariate regression was implemented to analyze the risk factors of bone metastasis of lung cancer. Receiver operating characteristic (ROC) curve was applied to analyze the diagnostic efficacy of the single test of ECT whole-body bone imaging, PINP, or β-CTX and the combination of the three tests.

Results: The differences in pathological type, clinical stage and EOD grading, the number of positive ECT cases, and the expression levels of PINP and β-CTX between the LCWBM and LCWOBM groups were statistically significant. In LCWBM patients with different EOD grading, the trends of the expression of PINP and β-CTX were grade 3 > grade 2 > grade 1 and grade 0. Further correlation analyses revealed that EOD grading showed a significant positive correlation with the PINP and β-CTX expression levels. Univariate logistic regression analysis demonstrated that adenocarcinoma, TNM stage IV, ECT positivity, and high expression of PINP and β-CTX were associated with bone metastasis of lung cancer, and multivariate logistic regression analysis indicated that ECT positivity, high expression of PINP and β-CTX were independent risk factors for bone metastasis of lung cancer. The area under the curve (AUC) of ECT, PINP, and β-CTX alone for the diagnosis of bone metastasis of lung cancer were 0.872, 0.888, and 0.874, respectively, and the AUC for the combined diagnosis of the three was 0.963, which was greater than that of any one of the individual indices, with a sensitivity of 86.96% and a specificity of 97.50% at a Youden index of 0.845.

Conclusion: ECT whole-body bone imaging combined with PINP and β-CTX has high diagnostic value for bone metastasis of lung cancer.