The goal of this work was to quantify the in vivo transport and binding parameters of [F-18]fallypride and the D2/D3 receptor density (B'max) in both the striatal (putamen, caudate, ventral striatum) and extrastriatal regions (thalamus, amygdala, cerebellum, temporal and frontal cortices) of the rhesus monkey brain. Multiple-injection PET experimental protocols with injections of radiolabeled and unlabeled doses of fallypride were used to estimate the K1, k2, kon/VR, koff and B'max kinetic parameters. The experimental design was chosen using the D-optimal criterion to maximize the precision of the estimated binding parameters for the various brain regions. There was a significant range in B'max for the putamen (27 pmol/mL), caudate (23 pmol/mL), ventral striatum (14 pmol/mL), thalamus (1.8 pmol/mL) and amygdala (0.9 pmol/mL). Significant receptor binding was also found in the cortical regions. Knowledge of these in vivo rate constants serves as a necessary step in using [F-18]fallypride PET to measure D2/D3 receptor density and drug occupancy in clinical research applications. We believe the precise parameter estimates derived from these complicated experimental protocols are necessary for proper application of drug occupancy and clinical research studies with [F-18]fallypride, which often rely on the validity of assumptions regarding the model parameters.

PurposeTo compare the diagnostic accuracy of biparametric MRI (bpMRI) and multiparametric MRI (mpMRI) for prostate cancer (PCa) and clinically significant prostate cancer (csPCa) and to explore the application value of dynamic contrast-enhanced (DCE) MRI in prostate imaging.Methods and materialsThis study retrospectively enrolled 235 patients with suspected PCa in our hospital from January 2016 to December 2017, and all lesions were histopathologically confirmed. The lesions were scored according to the Prostate Imaging Reporting and Data System version 2 (PI-RADS V2). The bpMRI (T2-weighted imaging [T2WI], diffusion-weighted imaging [DWI]/apparent diffusion coefficient [ADC]) and mpMRI (T2WI, DWI/ADC and DCE) scores were recorded to plot the receiver operating characteristic (ROC) curves. The area under the curve (AUC), accuracy, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) for each method were calculated and compared. The patients were further stratified according to bpMRI scores (bpMRI ≥3, and bpMRI = 3, 4, 5) to analyse the difference in DCE MRI between PCa and non-PCa lesions (as well as between csPCa and non-csPCa).ResultsThe AUC values for the bpMRI and mpMRI protocols for PCa were comparable (0.790 [0.732–0.840] and 0.791 [0.733–0.841], respectively). The accuracy, sensitivity, specificity, PPV and NPV of bpMRI for PCa were 76.2, 79.5, 72.6, 75.8, and 76.6%, respectively, and the values for mpMRI were 77.4, 84.4, 69.9, 75.2, and 80.6%, respectively. The AUC values for the bpMRI and mpMRI protocols for the diagnosis of csPCa were similar (0.781 [0.722–0.832] and 0.779 [0.721–0.831], respectively). The accuracy, sensitivity, specificity, PPV and NPV of bpMRI for csPCa were 74.0, 83.8, 66.9, 64.8, and 85.0%, respectively; and 73.6, 87.9, 63.2, 63.2, and 87.8%, respectively, for mpMRI. For patients with bpMRI scores ≥3, positive DCE results were more common in PCa and csPCa lesions (both P = 0.001). Further stratification analysis showed that for patients with a bpMRI score = 4, PCa and csPCa lesions were more likely to have positive DCE results (P = 0.003 and P < 0.001, respectively).ConclusionThe diagnostic accuracy of bpMRI is comparable with that of mpMRI in the detection of PCa and the identification of csPCa. DCE MRI is helpful in further identifying PCa and csPCa lesions in patients with bpMRI ≥3, especially bpMRI = 4, which may be conducive to achieving a more accurate PCa risk stratification. Rather than omitting DCE, we think further comprehensive studies are required for prostate MRI.

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BackgroundTuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder characterized by the development of numerous benign tumors. Renal angiomyolipoma (RAML) occur in up to 80% of TSC patients, which is a leading cause of TSC-related death in adult patients. The aim of the study was to evaluate the efficacy and safety profiles of everolimus in Chinese patients of TSC associated with RAML(TSC-RAML).MethodsIn this 2-years, nonrandomized, open-label trial, 18 patients of TSC-RAML, with at least one RAML 3 cm or larger in its longest diameter, were enrolled to assess the efficacy and safety of everolimus therapy in Chinese patients. Everolimus was administered for the first 12 months only. The primary endpoint was a reduction of 50% or more relative in RAML volume to the baseline in the absence of new RAML ≥1 cm and no RAML-related bleeding of grade ≥ 2. The secondary endpoints included: safety, lung function and skin lesions response rate. Serial computed tomography of RAML, magnetic resonance imaging of brain lesions and pulmonary-function tests were performed. Adverse events were investigated using CTCAE v4.0. All analyses used a significance level of 0.05 and were generated in SPSS19.0 software.ResultsThe proportion of patients who achieved ≥50% reduction from baseline in the sum of volumes of target lesions increased from 52.94% at 3 months, to 58.82% and 66.67% at months 6 and 12, respectively. During the period of everolimus therapy, among patients with lymphangioleiomyomatosis, the mean forced expiratory volume in 1 s (FEV1) increased by 276 ± 78 ml (P < 0.001), the forced vital capacity (FVC) increased by 433 ± 170 ml (P < 0.001), and the residual volume decreased by 408 ± 243 ml (P = 0.009), as compared with baseline values. The angiomyolipoma volume and the lung function approached, but did not completely return to, the baseline values. The skin lesions response rate was 37.5% after 12 months of therapy falling to 21.4% at 12 months after stopping everolimus. The most common adverse events were mucositis oral, irregular menstruation, abdominal pain, hypertriglyceridemia and headache. The most common grade 3 adverse events were irregular menstruation and mucositis oral. In addition, one patient died from RAML spontaneous haemorrhage during treatment with everolimus, even with reduction in RAML volume of 60.68% at 3 months. A second death was due to epithelioid RAML progression, with metastasis to multiple retroperitoneal lymph node, who died from severe infection one month after surgery.ConclusionsAngiomyolipomas regressed somewhat during everolimus therapy but tended to increase in volume after the therapy was stopped. Everolimus was well tolerated and showed promising activity in Chinese patients with TSC-RAML, however, we should alert the life-threatening hemorrhage of large RAML in the early period and the lymph node metastasis of epithelioid RAML.Trial registrationChiCTR-OPC-14005488. Registered November 17, 2014.Electronic supplementary materialThe online version of this article (10...

CTTA proved to be a feasible tool for differentiating LGUC from HGUC. MPP quantified from fine texture scale on unenhanced images was the optimal diagnostic parameter for estimating histologic grade of urothelial carcinoma.

Background Computed tomography texture analysis (CTTA) has gained an increasing role in oncology and has successfully demonstrated to reflect biological associations with glucose metabolism, hypoxia, angiogenesis, and even genetic variation. Purpose To determine whether quantitative CTTA can be used to differentiate metastases from benign adrenal masses on single energy CT images. Material and Methods A total of 225 patients with 265 histologically confirmed adrenal masses (101 metastases, 98 pheochromocytomas, and 66 lipid-poor adenomas) were included in this retrospective study. CTTA was performed and six texture parameters (including mean, SD of pixel distribution histogram, mean of positive pixels, entropy, kurtosis, skewness) across six spatial scaling factor (SSF) were recorded on both unenhanced and contrast-enhanced CT images. Receiver operating characteristic (ROC) analysis was performed and the area under the ROC curve (AUC) was calculated using the significant texture parameters for the objective. Diagnostic performance was evaluated using the cut-off values of texture parameters by ROC analysis. The optimal discriminative texture parameters were used to produce support vector machine (SVM) classifiers. Diagnostic accuracy and 10-fold cross-validation was performed. Results Compared to benign adrenal masses, metastases had significantly lower mean gray-level intensity, SD, entropy, mean of positive pixels and kurtosis on unenhanced images (P < 0.0083). On contrast-enhanced CT images, except for skewness and kurtosis, the other four texture texture-quantifiers were lower in the metastatic compared to the other group (P < 0.0083). A model incorporating mean, SD, entropy and mean value of positive pixels produced an AUC of 0.85 ± 0.03 with an SVM accuracy of 77% to identify metastatic from benign adrenal masses. Conclusion Differentiation of metastatic and benign adrenal masses can be achieved accurately with CTTA on contrast-enhanced CT images.

Object:The purpose was to highlight the diagnosis and treatment of extra-adrenal para-gangliomas, which often causes catecholamine hypersecretion and hypertension.Methods:67 cases of extra-adrenal paraganglioma of retroperitoneum proven pathologically from 1999 to 2009 were reviewed and studied after operation. Endocrine secretion examinations, B-US, CT, MRI, 131-MIBG, octreotide and hands microcirculation inspection were used to diagnose the disease.Results:All patients underwent successful surgical resection of the tumors, which proved to be paragangliomas. They were from 3 cm to 25 cm in size. Almost all of them were diffusely positive for cgA, syn, NSE and s-100 by immunohitochemical staining. There were nine cases assayed malignant paraganglioma by the follow-up.Conclusions:131-MIBG and octreotide have high sensitivity and accuracy in diagosing extra-adrenal paraganglioma. Surgical treatment should be carried out on the basis of correct drug preparation of α-receptor blocker, such as prazosin and phenoxybenzamine. Complete surgical excision is the treatment of choice for extra-adrenal paragangliomas as well as recurrent or metastatic disease, which could be resected laparoscopically. Intimate lifelong follow-up is necessary and important.