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Objective To compare the efficacy of 18F-FDG PET/CT, 99Tcm-MDP bone scintigraphy (BS), and combination of the two techniques (PET/CT + BS) for detecting bone metastasis by ROC curve analysis. Methods All 296 patients with various cancers, who underwent both 99Tcm-MDP BS and 18F-FDG PET/CT within two months, were retrospectively analyzed. These images were interpreted according to 5-point scale (0: definitely negative, 1: probably negative, 2: equivocal, 3: probably positive, 4:definitely positive for bone metastasis), and the scale of PET/CT + BS was the sum of PET/CT and BS. In light of the confirmed diagnosis derived from pathology or follow-up, ROC curve analysis was performed.The area under the ROC curve (AUC) was compared by z-test. Results Of 296 cases, 61 (20.6%) were confirmed as bone metastases and 235 (79.4%) were negative. The AUC were 0. 919 (95% confidence interval (95% CI) :0. 867 - 0. 971) for BS, 0. 949 (95% CI: 0. 906 - 0. 991) for PET/CT, and 0. 994 (95% CI: 0.988-0.999) for PET/CT + BS, rctrospectively. The AUC of PET/CT + BS was statistically significantly larger than that of BS (z=2. 866, P=0.004) or PET/CT (z =2.027, P=0.043), while the AUC of PET/CT was larger than that of BS, but no statistically significance (z = 0. 881, P = 0. 378) was showed. The optimal sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value(NPV) were 90. 2% (55/61), 85. 1% (200/235), 86. 1% (255/296), 61. 1% (55/90), 97. 1%(200/206) for BS, 88.5% (54/61), 97.0% (228/235), 95.3% (282/296), 88.5% (54/61), 97.0% for PET/CT, and 98.4% (60/61), 95.7% (225/235), 96.3% (285/296), 85.7% (60/70) for PET/CT + BS,respectively. The specificity (χ2 = 19.862, P<0. 001), accuracy (χ2 = 23. 361, P<0.001) and PPV (χ2 =11. 791, P =0.001) of PET/CT + BS were significantly higher than those of BS, the sensitivity of PET/CT +BS was significantly higher than that of PET/CT (χ2 =4.167, P=0.031). Compared with BS, PET/CT had a higher specificity (χ2 = 19.600, P<0. 001), accuracy (χ2 = 13. 755, P <0. 001), PPV (χ2 = 13. 608, P <0. 001), but their sensitivity showed no statistically significant difference (χ2 = 0, P = 1. 000). Conclusions The efficacy of 18F-FDG PET/CT for detecting malignant bone metastasis was superior to that of 99Tcm-MDP BS alone. The detection ability can be obviously improved by combination of the two techniques.
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Objective To determine the effect of histotype and histodifferentiation on the maximum standardized uptake value (SUV_(max)) of non-small cell lung cancer (NSCLC) ~(18)F-fluorodeoxyglucose (FDG) PET/CT imaging.Methods Two hundred and sixty patients with NSCLc underwent ~(18)F-FDG PET/CT imaging.They were classified according to (1) histotype:as adenocarcinoma (AC),squamous cell carcinoma(SQC),adenosquamous carcinoma (ASC) and other type carcinoma (OTC),and (2) histodifferentiation:as grade Ⅰ (well-differentiated),grade Ⅱ (moderate-differentiated) and grade Ⅲ (poor-differentiated).The SUV_(max) and size(long diameter)of the primary lesions were measured.Multivariate regression analysis was used to analyze the relationship between the SUV_(max) and variable factors including histotype,histodifferentiation,lesion size,age,sex,body height,body weight,body mass index (BMI),blood glucose level,dose,and rate of dose.Results Two hundred and sixty patients had 260 primary NSCLC tumors.There were 161 AC(15 grade Ⅰ,88 grade Ⅱ,58 grade Ⅲ),74 SQC(6 grade Ⅰ,39 grade Ⅱ,29 grade Ⅲ),15 ASC(7 grade Ⅱ,8 gradeⅢ)and OTC(8 large cell,2 carcinosarcoma).Only lesion size (F=87.046.P＜0.001),histodifferentiation (F=87.604,P＜0.001) and histotype (F=66.663,P＜0.001) were included for multivariate regression analysis with SUV_(max).After adjustment for lesion size,the SUV_(max)(mean and 95%confidence interval) in ascending order was AC Ⅰ:3.3(2.1-4.5),ACⅡ:6.0(5.5-6.6),SQCⅠ:6.1(4.2-8,0),ASC Ⅱ:6.6(4.8-8.4),SQCⅡ.7.8(7.0-8.6),OTC:8.1(6.6-9.6),AC Ⅲ:8.3(7.6-8.9),ASC Ⅲ:8.7(7.0-10.4),and SQC Ⅲ:8.9(8.0-9.8).11he SUV_(max) of AC Ⅰ was significantly lower than that of SQC Ⅰ(q=-2.786,P=0.017),same for AC Ⅱ and SQC Ⅱ(q=-1.776,P＜0.001),but no statistically significant differences were found among AC Ⅲ,ASC Ⅲ and SQC Ⅲ(q=-0.593,-0.422,0.171,P=0.288,0.642,0.860,respectively).For the same histotype lesions,the difference of SUV_(max) among AC Ⅰ,Ⅱ and Ⅲ was statistically significant(q=-2.720,-4.943,-2.223,all P＜0.001),as also for SQC Ⅰ and Ⅲ(q=-2.751,P=0.012).Conclusion Histotype and histodifferentiation are significant correlative factors for ~(18)F-FDG uptake of NSCLC,with histodifferentiation being the factor with greater impact.
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<p><b>OBJECTIVE</b>To investigate the diagnostic value of dual-head (18)F-fluorodeoxyglucose ((18)F-FDG) imaging in metastatic lesion with unknown primary tumour (UPT).</p><p><b>METHODS</b>Seventy patients with UPT underwent dual-head (18)F-FDG imaging after iv (18)F-FDG 1.85 MBq/kg. The primary tumour was diagnosed according to the FDG uptake and T/N value.</p><p><b>RESULTS</b>Of the 70 patients, the primary tumour was identified by positive FDG imaging and finally confirmed pathologically in 58 patients (82.9%), and 12 patients had a negative FDG imaging (17.1%). Forty-two of the 58 positive patients were found to have lung cancer (72.4%). Among the 12 negative patients, their primary tumour was then identified by other diagnostic procedures in 5 patients (41.7%), in 1 patient, the primary site was detected during follow-up, however, the primary tumour was never detected in the rest 6 patients.</p><p><b>CONCLUSION</b>Dual-probe (18)F-FDG imaging is a simple, quick, non-invasive and sensitive technique with an accuracy over 80% in the diagnosis of unknown primary tumour. The lung is found to be the most frequent primary site. Dual-probe (18)F-FDG imaging can be recommended as the first diagnostic choice for UPT.</p>