Comparison Of ¹⁸F-DCFPyL PET/CT Imaging And ^99mTc-MDP SPECT/CT Bone Imaging In The Diagnosis Of Bone Metastases In Prostate Cancer

Objective:To compare the diagnostic efficacy of ¹⁸F-DCFPy L PET/CT imaging and ^99mTc-MDP SPECT/CT imaging in bone metastasis of prostate cancer.Methods:A retrospective analysis was performed on 31 patients who were pathologically diagnosed with prostate cancer in China-Japan Union Hospital of Jilin University from September 2020 to September 2022.All patients received ^99mTc-MDP SPECT/CT and¹⁸F-DCFPy L PET/CT imaging at the same time.With pathological or clinical best valuable criteria（BVC）results as the the final diagnostic criteria,the sensitivity,specificity,accuracy,positive predictive value（PPV）and negative predictive value（NPV）of the two imaging methods in the diagnosis of bone metastases of prostate cancer were calculated based on patient and lesion level,respectively.The paired sample chi-square test（Mc Nemar test）was used to compare the above indicators of the two imaging methods.Meanwhile,the receiver operating characteristic curve（ROC）of the two imaging methods was drawn to calculate the area under the curve（AUC）of the two imaging methods.The AUC values of the two imaging methods were compared by Z-test,so as to compare the diagnostic efficiency of the two imaging methods.P<0.05was considered to be statistically significant.In addition,the ability of ¹⁸F-DCFPy L PET/CT imaging to detect metastases other than bone metastases was briefly analyzed.Results:According to pathological or BVC findings,bone metastases were present in 18of 31 patients with prostate cancer,with a total of 84 bone metastatic lesions.Based on patient level analysis,¹⁸F-DCFPy L PET/CT imaging showed higher diagnostic efficacy than ^99mTc-MDP SPECT/CT imaging in the diagnosis of prostate cancer bone metastases:Sensitivity（100%VS.77.8%,P<0.01）,specificity（92.3%VS.69.2%,P<0.05）,accuracy（96.8%VS.74.2%,P<0.01）,PPV（94.7%VS.77.8%,P<0.01）,NPV（100%VS.69.2%,P<0.01）.The AUC values of ¹⁸F-DCFPy L PET/CT and ^99mTc-MDP SPECT/CT were 0.962 and 0.735,respectively,and the difference was statistically significant（Z=2.168,P<0.05）.Based on lesion level analysis,¹⁸F-DCFPy L PET/CT imaging was higher than ^99mTc-MDP SPECT/CT imaging in the diagnosis of bone metastases of prostate cancer.Sensitivity（97.6%VS.72.6%,P<0.01）,specificity（95.7%VS.73.9%,P<0.01）,accuracy（97.2%VS.72.9%,P<0.01）,PPV（98.8%VS.91.0%,P<0.01）,NPV（91.7%VS.42.5%,P<0.01）.The AUC values of ¹⁸F-DCFPy L PET/CT and ^99mTc-MDP SPECT/CT were 0.966 and 0.733,respectively,and the difference was statistically significant（Z=3.541,P<0.001）.In addition,among the 18 prostate cancer patients with bone metastases,the ¹⁸F-DCFPy L PET/CT imaging also detected lymph node metastases in 9（50.0%）,lung metastases in 3（16.7%）,liver metastases in 2（11.1%）,and splenic and pleural metastases in 1（5.6%）each.Conclusion:¹⁸F-DCFPy L PET/CT imaging is superior to ^99mTc-MDP SPECT/CT imaging in the diagnosis of bone metastases of prostate cancer.In addition,¹⁸F-DCFPy L PET/CT imaging is of great value in the detection of metastatic lesions other than bone metastases of prostate cancer.