Objectives To evaluate the relationship between semiquantitative and volumetric parameters on 18F-FDG PET/computed tomography (CT), including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), tumor to liver ratio (TLR) and tumor to mediastinum ratio (TMR) with the level of Ki-67 expression in breast cancer. Patient and methods We retrospectively reviewed 105 female patients with newly diagnosed breast cancer who underwent baseline 18F-FDG PET/CT and had immunohistochemical staining to determine the level of Ki-67 expression. The following PET parameters were measured (SUVmax, SUVmean, MTV, TLG, TLR and TMR) and correlated with level of Ki-67 expression. Results Significant moderate positive correlations were found between the PET parameters (primary SUVmax, SUVmean, TLG, TLR and TMR) and level of Ki-67 expression. The primary SUVmax had the highest correlation coefficient (r = 0.461) followed by TMR (r = 0.455) and P value of <0.001 for both. In ROC analysis, primary SUVmax had the largest area under the curve (0.806, P = 0.0001), with sensitivity of 76.5 % and specificity of 75% for prediction of high Ki-67 level. In univariate analysis, all PET parameters, patient age, tumor grade, molecular subtype, estrogen receptor and progesterone receptor status were significantly associated with Ki-67 level. In multivariate regression analysis, only tumor grade [odds ratio (OR) = 20.460, 95% confidence interval (CI): 11.360–29.559, P = <0.0001], molecular subtype (OR = −21.894, 95% CI: −37.921 to −5.866, P = 0.008), SUVmax (OR = 2.299, 95% CI: 0.703–3.895, P = 0.005) and TLR (OR = −4.908, 95% CI: −9.476 to −0.340, P = 0.035) were found to be the strongest independent predictor factors for the level of Ki-67 expression and hence proliferative activity of malignant cells in breast cancer. Conclusion The semiquantitative parameters and volumetric 18F-FDG PET/CT parameter, that is, TLG correlated well with proliferation marker Ki-67 in breast cancer. 18F-FDG PET/CT imaging can be used as a useful noninvasive diagnostic tool in imaging cellular proliferation and hence may substitute for in vitro testing of molecular markers in the diagnoses and staging of breast cancer.

Background Biliary atresia (BA) and neonatal hepatitis (NH) are the two major causes of neonatal cholestasis (NC). However, both conditions had entirely different therapeutic schedule and prognosis. Considering BA as a surgical emergency, it is pretty important to accurately differentiate the two entities. The aim of the study is to evaluate the diagnostic utility of hepatobiliary scintigraphy (HBS) using a semi-quantitative technique as well as 15-point histopathological scoring system in differentiating BA from NH. Results The sensitivity, specificity, and overall accuracy of HBS in the diagnosis of BA was 90.5%, 80%, and 83.6%, respectively. The median values of kidney-liver ratio (KLR), intestinal-liver ratio (ILR), and background-liver ratio (BLR) were significantly higher in patients with BA, while that of the liver-kidney ratio (LKR) was significantly lower in cases with BA. Moreover, KLR had the largest area under curve (AUC); advocates it to be the best of the semi-quantitative parameters that can predicts BA. Histopathological scoring using a cutoff point ≥ 7 was helpful in discriminating BA from NH with 85.7% sensitivity, 95% specificity and 91.8% accuracy. Conclusions HBS is a non-invasive diagnostic tool frequently used in diagnosis of BA, yet it has a relatively low specificity. To overcome this challenge, we kindly recommend the use of semi-quantitative parameters that could possibly improve the accuracy of HBS for diagnosing BA. Additionally, the use of 15-point scoring for liver biopsy was useful.

Objectives To investigate the effect of serum glucose level and other confounding factors on the variability of maximum standardized uptake value (SUVmax) in normal tissues within the same patient on two separate occasions and to suggest an ideal reference tissue. Materials and Methods We retrospectively reviewed 334 18F-FDG PET/CT scans of 167 cancer patients including 38 diabetics. All patients had two studies, on average 152 ± 68 days apart. Ten matched volumes of interest were drawn on the brain, right tonsil, blood pool, heart, lung, liver, spleen, bone marrow, fat, and iliopsoas muscle opposite third lumber vertebra away from any pathological 18F-FDG uptake to calculate SUVmax. Results SUVmax of the lungs and heart were significantly different in the two studies (P = 0.003 and P = 0.024 respectively). Only the brain uptake showed a significant moderate negative correlation with the level of blood glucose in diabetic patients (r = −0.537, P = 0.001) in the first study, while the SUVmax of other tissues showed negligible or weak correlation with the level of blood glucose in both studies. The liver showed significant moderate positive correlation with body mass index (BMI) in both studies (r = .416, P = <0.001 versus r = 0.453, P = <0.001, respectively), and blood pool activity showed significant moderate positive correlation with BMI in the first study only (r = 0.414, P = <0.001). The liver and blood pool activities showed significant moderate negative correlation with 18F-FDG uptake time in first study only (r = −0.405, P-value = <0.001; and r = −0.409, P-value = <0.001, respectively). In the multivariate analysis, the liver showed a consistent effect of the injected 18F-FDG dose and uptake duration on its SUVmax on the two occasions. In comparison, spleen and muscle showed consistent effect only of the injected dose on the two occasions. Conclusion The liver, muscle, and splenic activities showed satisfactory test/retest stability and can be used as reference activities. The spleen and muscle appear to be more optimal reference than the liver, as it is only associated with the injected dose of 18F-FDG.

Purpose To assess the value of posttherapy 99mTc-pentavalent dimercaptosuccinic acid (DMSA-V) brain SPECT/CT in patients with brain glioma. Methods Patients with pathologically or radiologically proven glioma were prospectively enrolled in this study. 99mTc-DMSA-V brain SPECT/CT images were acquired at 120–180 min after i.v. injection of 555–740 MBq of 99mTc-DMSA-V. Three nuclear medicine physicians blindly interpreted the scans visually as positive or negative for residual/recurrent disease. Agreement between two or more readers was considered a consensus. The composite reference standard was considered based on subsequent clinical/neuroimaging follow-up or histopathology whenever available. Overall survival (OS) was calculated from the date of initial diagnosis till the death or the date of last follow-up. Results Thirty-four patients (18 males and 16 females; mean age 37.7 ± 16 years) were enrolled in this study. Interreader agreement between the readers ranged from 0.71 to 0.82. Based on the composite reference standard, residual/recurrent disease was confirmed in 16 patients, whereas 18 patients were negative for disease. Consensus reading of 99mTc-DMSA-V SPECT/CT accurately diagnosed 13 true positive (sensitivity 81%) and 17 true negative scans (specificity 94%). After a median follow-up of 22.9 months, 7/14 patients with positive 99mTc-DMSA-V SPECT/CT brain readings died compared to 4/20 with negative readings. The median survival was 24.1 months for the positive group and was not reached for the negative group. Conclusion Posttherapy brain SPECT/CT scanning with 99mTc-DMSA-V is a noninvasive, reliable, and specific tool for evaluation of patients with brain glioma after definitive therapy. Scan positivity was associated with poor OS.