99mTc-MDP SPECT/CT联合血清碱性磷酸酶和钙离子诊断单发骨转移瘤

Objective To investigate the clinical value of 99mTc methylene diphosphonate (MDP) SPECT/CT bone imaging combined with serum alkaline phosphatase (ALP) and calcium ion (Ca2+) in the diagnosis of benign and malignant nature of single bone tumors. Methods 106 patients with confirmed malignant tumors and single bone tumors in our hospital from January 2021 to December 2022 were included. After admission, 99mTc MDP SPECT/CT whole body and local bone imaging was completed and serum ALP and Ca2+levels were detected. Routine follow-up for at least 6 months, based on the pathological or comprehensive imaging (CT and MRI) findings of bone tumors, the diagnosis of benign and malignant bone tumors should be made. Results There were 44 confirmed cases of bone metastases and 62 negative cases, the gender, age, and primary tumor types of the two groups were comparable (P>0.05). Bone imaging diagnosed 53 cases of bone metastases and 53 cases were negative. The accuracy of bone imaging in diagnosing bone metastases was 78.3% [(37+46)/106], sensitivity was 84.1% (37/44), specificity was 74.2% (46/62), positive predictive value was 69.8% (37/53), and negative predictive value was 86.8% (46/53). The serum ALP and Ca2+levels in the bone metastasis group were significantly higher than the negative group (P<0.05). ROC showed AUC of bone imaging combined with ALP+Ca2+for the diagnosis of bone metastases was 0.876 (95% CI=0.823~0.924, P<0.001), sensitivity of 88.6% and specificity of 90.5%. Conclusion 99mTc MDP SPECT/CT bone imaging could provide structural changes and functional metabolic characteristics of single bone metastases, with good sensitivity, but limited specificity and accuracy. Combining serum ALP and Ca2+can furtherly improve diagnostic performance and has important clinical potential.