An Imaging and Histological Study on Intrahepatic Microvascular Passage of Contrast Materials in Rat Liver.

Background. Lipiodol has been applied for decades in transarterial chemoembolization to treat liver malignancies, but its intrahepatic pathway through arterioportal shunt (APS) in the liver has not been histologically revealed. This rodent experiment was conducted to provide evidence for the pathway of Lipiodol delivered through the hepatic artery (HA) but found in the portal vein (PV) and to elucidate the observed unidirectional APS. Methods. Thirty rats were divided into 5 groups receiving systemic or local arterial infusion of red-stained iodized oil (RIO) or its hydrosoluble substitute barium sulfate suspension (BSS), or infusion of BSS via the PV, monitored by real-time digital radiography. Histomorphology of serial frozen and paraffin sections was performed and quantified. Results. After HA infusion, RIO and BSS appeared extensively in PV lumens with peribiliary vascular plexus (PVP) identified as the responsible anastomotic channel. After PV infusion, BSS appeared predominantly in the PV and surrounding sinusoids and to a much lesser extent in the PVP and HA (P < 0.001). Fluid mechanics well explains the one-way-valve phenomenon of APS. Conclusions. Intravascularly injected rat livers provide histomorphologic evidences: (1) the PVP exists in between the HA and PV, which is responsible to the APS of Lipiodol; and (2) the intrahepatic vascular inflow appears HA-PVP-PV unidirectional without a physical one-way valve, which can be postulated by the fluid mechanics.

Is Tc-99m sestamibi scintimammography useful in the prediction of neoadjuvant chemotherapy responses in breast cancer? A systematic review and meta-analysis.

To evaluate the accuracy of Tc-99m sestamibi (MIBI) scintimammography in the prediction of neoadjuvant chemotherapy response in breast cancer. 'PubMed' (MEDLINE included) and Embase database were searched for relevant publications in English. Methodological quality of the included studies was assessed with Quality Assessment of Diagnosis Accuracy Studies (QUADAS), and 'Meta-Disc' and 'Stata' software were used to determine pooled sensitivity, specificity, and diagnostic odds ratio (DOR), and construct a summary receiver-operating characteristic curve. Fourteen studies (a total of 503 individuals) fulfilled the inclusion criteria. The pooled sensitivity was 0.86 [95% confidence interval (CI): 0.78-0.92] and the pooled specificity was 0.69 (95% CI: 0.64-0.74). Pooled likelihood ratio (LRp), negative likelihood ratio (LR-), and DOR were 2.64 (95% CI: 1.81-3.85), 0.26 (95% CI: 0.15-0.46), and 12.06 (95% CI: 6.94-20.96), respectively. The area under the summary receiver-operating characteristic curve was 0.86. For the prediction of pathological complete response (10 studies included), the pooled sensitivity and specificity and DOR were 0.86 (95% CI: 0.77-0.93), 0.67 (95% CI: 0.62-0.72), and 11.43 (95% CI: 5.95-21.97). Our results indicated that Tc-99m MIBI scintimammography had acceptable sensitivity in the prediction of neoadjuvant chemotherapy response in breast cancer; however, its relatively low specificity showed that a combination of other imaging modalities would still be needed. Subgroup analysis indicated that performing early mid-treatment Tc-99m MIBI scintimammography (using the reduction rate of one or two cycles or within the first half-courses of chemotherapy compared with the baseline) was better than carrying out later (after three or more courses) or post-treatment scintimammography in the prediction of neoadjuvant chemotherapy response.

A multifunctional contrast dye for morphological research.

OBJECTIVES: We sought to devise and test a multifunctional contrast dye agent for X-ray based digital radiography (DR) or computer tomography (CT), magnetic resonance imaging (MRI), and colored staining in ex vivo validation part of animal experiments. MATERIALS AND METHODS: The custom-formulated contrast dye namely red iodized oil (RIO) was prepared by solubilizing a lipophilic dye Oil Red O in iodized poppy seed oil (Lipiodol or LPD) followed by physicochemical characterizations. To explore and test the utility of RIO, normal rats (n = 10) and rabbits (n = 10) with myocardial infarction (MI) were euthanized by overdose of pentobarbital for infusion of RIO through catheterization. The bodies and/or excised organs including heart, liver, spleen, kidneys, pancreas, and intestines of the rats and rabbits were imaged at clinical mammography, CT and MRI units. These images were qualitatively studied and quantitatively analyzed using Wilcoxon Rank test with a P value < 0.05 being considered of a statistically significant difference. Imaging findings were verified by histomorphology. RESULTS: All experimental procedures were carried out successfully with the use of RIO. T1 and T2 relaxation time was 234.2 ± 2.6 ms and 141.9 ± 3.0 ms for RIO, close to that of native LPD. Proton ((1) H) NMR spectroscopy revealed almost identical profiles between RIO and native LPD. The clinical mammography unit, 128-slice CT scanner and 3.0T MRI magnet were well adapted for the animal experiments. Combined use of RIO with DR, MRI, CT and histology enabled microangiography of the organs, 3D visualization of rat pancreas, validation of in vivo cardiac quantification of MI and cause determination of the rabbit death after coronary occlusion. RIO appeared as red droplets and vacuoles in vessels by frozen and paraffin sections. Image analysis showed the superiority of DR images, which provided better overall image quality (4.35 ± 0.49) for all analyzed liver vessel segments. MRI images revealed moderate to good overall image quality ratings (3.45 ± 0.52). Comparing the signal intensities of vessel and liver with different MRI sequences, all P values were <0.01. CONCLUSIONS: RIO proved to be a multifunctional contrast dye, which could be applied as an imaging biomarker for tissue vascularity or blood perfusion, for visualization of organ anatomy and for ex vivo validation of in vivo animal experiments.

Prognostic significance of (18)FDG PET/CT in colorectal cancer patients with liver metastases: a meta-analysis.

BACKGROUND: The role of 18-fluorodeoxyglucose positron emission tomography CT ((18)FDG PET/CT), as a prognostic factor for survival in colorectal cancer patients with liver metastases, is still controversial. We sought to perform a meta-analysis of the literature to address this issue. METHODS: A systematic literature search was performed to identify the studies that associated (18)FDG PET/CT to clinical survival outcomes of patients with liver metastases. Methodological qualities of the included studies were also assessed. The summarized hazard ratio (HR) was estimated by using fixed- or random-effect model according to heterogeneity between trails. RESULTS: By analyzing a total of 867 patients from 15 studies, we found that PET/CT for metabolic response to the therapy was capable of predicting event-free survival (EFS) and overall survival (OS) with statistical significance, and the HR was 0.45 (95% confidence interval [CI], 0.26-0.78) and 0.36 (95% CI, 0.18-0.71), respectively. Furthermore, pre-treatment (18)FDG PET/CT with high standardized uptake value (SUV) was also significantly associated with poorer OS HR, 1.24; (95% CI, 1.06-1.45). However, we did not find a statistically significant effect of post-treatment SUV for predicting OS HR, 1.68; (95% CI, 0.63-4.52). CONCLUSIONS: The present meta-analysis confirms that (18)FDG PET/CT is a useful tool to help predict survival outcomes in patients with liver metastases.

Differentiation between Malignant and Benign Solitary Lesions in the Liver with (18)FDG PET/CT: Accuracy of Age-related Diagnostic Standard.

OBJECTIVE: This study was to determine the reliability of age-stratified diagnostic index in differential diagnosis of malignant and benign solitary lesions in the liver using fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG PET/CT). METHODS: The enrolled 272 patients with solitary lesions in the liver were divided into three age groups, younger group (under 50 years), middle-aged group (50-69 years), and elderly group (70 years and above). Patients' ages were compared, and the optimal cut-offs of the standard uptake value (SUV) ratio (tumor-to-non-tumor ratio of the SUV), as well as areas under the curves (AUC), were evaluated in terms of malignant and benign lesions in each age group by using receiver operating characteristic (ROC) analysis. Based on optimal cut-offs, the sensitivity, specificity, accuracy were calculated, and the diagnostic accordance rate was compared between each age group and all patients, supported by (18)FDG PET/CT imaging data. RESULTS: There was a significant age difference between the malignant and benign groups (t=3.905 p=0.0001). ROC analysis showed that the optimal cut-off value in all patients, younger group, middle-aged group and elderly group was 1.25, 1.17, 1.45 and 1.25 for SUVratio, and 0.856, 0.962, 0.650, 0.973 for AUC. The chi-square test proved that diagnostic accordance rate of (18)FDG PET/CT in younger group and elderly group were superior to that in all patients (χ(2)=13.352, P=0.0003) and (χ(2)=8.494, P=0.0036). Conversely, overall diagnostic accordance rate in all patient group was higher than that in middle-aged group (χ(2)=9.057, P=0.0026). Representative (18)FDG PET/CT imaging findings are demonstrated. CONCLUSION: This study indicates that diagnostic optimal cut-offs of SUVratio of liver solitary lesions of (18)FDG PET/CT were different in each age group. In addition, the diagnostic performance of SUVratio was better in younger and elderly groups than that in all patients, and was poorer in middle-aged group than that in all patients. Therefore, age difference appears to be one of the important factors for discriminating malignant liver lesions from benign ones using (18) FDG PET/CT.

Is there an impact of 18F-FDG PET/CT on the surveillance and clinical management of recurrent ovarian cancer? Research based on a large sample in a single PET/CT center.

OBJECTIVES: The aim of the study was to evaluate the use of F-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (CT) in the follow-up and clinical management of ovarian cancer patients after therapy. MATERIALS AND METHODS: A total of 152 ovarian cancer patients who had undergone therapy were evaluated. Clinical information, CA-125 levels, and traditional imaging findings were analyzed. According to the indication for PET/CT the patients were divided into five groups for assessing the role of (18)F-FDG PET/CT in the clinical management of ovarian cancer patients after therapy. A comparison was made between the PET/CT findings and the results of clinical follow-up. RESULTS: Of the 152 patients, 137 had follow-up results and 15 were lost to follow-up. A total of 105 patients were found to have recurrent tumor and 32 were found to be disease-free after long-term follow-up. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 98.3, 91.2, 96.8, 97.5, and 93.9%, respectively. PET/CT was especially useful in patients when indications were to diagnose suspected recurrence, assess disease progression, and evaluate therapeutic response. CONCLUSION: PET/CT has been proven to be extremely valuable in the evaluation of patients with recurrent ovarian cancer and is particularly helpful in guiding treatment planning.

Correlation of fluorodeoxyglucose uptake and tumor-proliferating antigen Ki-67 in lymphomas.

OBJECTIVE: To investigate the correlation between cellular proliferation and the fluorodeoxyglucose (FDG) uptake in positron emission tomography/computed tomography (PET/CT) imaging by comparing 50 cases of different subtypes of lymphoma. MATERIALS AND METHODS: Fifty cases of lymphomas were collected. Each case was labeled with Ki-67 stain, a marker of cellular proliferation, and a PET/CT examination was performed. All lymphoma cases were sorted according to the World Health Organization's classification, and the International Non-Hodgkin's Lymphoma Working Formulation was used to differentiate groups of large and small cell non-Hodgkin's lymphoma. The Ki-67 staining was described as slight, mild, middle, or strong according to the nuclear staining of positive cells. FDG uptake by lesions in PET/CT images was semi-quantitatively analyzed to calculate the average standard uptake value. The statistics software SPSS13.0 was used to calculate the mean and standard deviation of the FDG uptake value of the lymphoma subtypes, the difference between the large and small cell lymphoma group with a Student's t-test, and the correlation between the Ki-67 level and FDG uptake of lesion with a Spearman's analysis. RESULTS: The FDG uptake value of large cell origin lymphoma was significantly higher than that of small cell origin lymphoma (t = 6.19, P < 0.01). The correlation coefficients between the Ki-67 level and FDG uptake value in lymph nodal and extranodal lesions was 0.750 and 0.843, respectively. CONCLUSIONS: Ki-67 staining, a reflection of tumor-proliferation activity, was significantly related to the FDG uptake value in lymphoma lesions.

Can ¹8F-fluorodeoxyglucose positron emission tomography predict responses to neoadjuvant therapy in oesophageal cancer patients? A meta-analysis.

OBJECTIVES: Neoadjuvant therapy for the treatment of oesophageal cancer was introduced in an effort to improve prognosis. Response assessment is crucial for the treatment of patients with oesophageal cancer. Currently, ¹8F-fluorodeoxyglucose positron emission tomography (¹8F-FDG PET) seems to be the best available tool to assess neoadjuvant therapy response in patients with oesophageal cancer. The purpose of this study was to assess the diagnostic value of ¹8F-FDG PET for the evaluation of neoadjuvant therapy responses in patients with oesophageal cancer using a meta-analysis. A unified procedure and evaluation standard for ¹8F-FDG PET in the assessment of neoadjuvant therapy response should be established. METHODS: All published English-language studies pertaining to the assessment of neoadjuvant therapy response in patients with oesophageal cancer using ¹8F-FDG PET in the MEDLINE and EMBASE databases were collected. The methodological quality of the included studies was evaluated according to the Quality Assessment of Diagnostic Accuracy Studies quality assessment tool. Pooled sensitivity, specificity, diagnostic odds ratios and summary receiver operating characteristic curves were obtained using statistical software. RESULTS: Thirteen studies included in the meta-analysis fulfilled the inclusion criteria of the Quality Assessment of Diagnostic Accuracy Studies quality assessment tool. The pooled sensitivity, specificity and diagnostic odds ratios for F-¹8FDG PET in the evaluation of neoadjuvant therapy response in patients with oesophageal cancer were 70.3% [95% confidence interval (CI): 64.4-75.8], 70.1% (95% CI: 65.1-74.8) and 9.389 (95% CI: 3.482-25.319), respectively. The area under the curve and the Q value for the summary receiver operating characteristic curve were 0.8244 and 0.7575, respectively. CONCLUSION: ¹8F-FDG PET has some value in the assessment of neoadjuvant therapy response in patients with oesophageal cancer. A 50% reduction in standardized uptake value between pretherapy and posttherapy positron emission tomography scans performed in the first 2 weeks after the initiation of neoadjuvant therapy is the optimal condition for predicting a response to neoadjuvant therapy in patients with oesophageal cancer.