Widespread micronodular hepatic metastases of neuroendocrine tumor detected by [68Ga]DOTATATE PET/CT.

Neuroendocrine tumors (NET) encompass a diverse, heterogeneous group of neoplasms that originate from the secretory cells of the neuroendocrine system. These neoplasms typically express the somatostatin receptor (SSTR), which can be targeted by molecular agents for imaging and therapy. This is particularly advantageous for imaging NETs that are indolent, slow-growing, and less well detected by [18F]FDG and for the detection of occult disease not easily identified by anatomic imaging. Herein, we present a case in which [68Ga]DOTATATE PET/CT was used to diagnose the etiology of biochemical recurrence in NET that was not apparent on MRI. The importance of understanding deviations from the normal biodistribution of the radiotracer is emphasized as key in interpreting nuclear medicine studies and establishing the diagnosis. Imaging the SSTR is of particular interest given the recent FDA approval of [68Cu]DOTATATE as a new and possibly more available molecular radiotracer.

Dose-dependent effects of ultrasound therapy on hepatocellular carcinoma.

Non-invasive ischemic cancer therapy requires reduced blood flow whereas drug delivery and radiation therapy require increased tumor perfusion for a better response. In this study we investigate the hypothesis that different dose models of antivascular ultrasound therapy (AVUS) can have opposite effects on hepatocellular carcinoma (HCC) tumor blood flow. HCC was induced in 22 Wistar rats by ingestion of diethylnitrosamine (DEN) for 12 weeks. Rats received AVUS treatment at low and high doses. Low dose group received 1 watt/cm2 ultrasound for 1 min with 0.2 mL microbubbles injected IV. High dose group received 2 watts/cm2 for 2 min with 0.7 mL microbubbles IV. A sham group did not receive any treatment. Tumor perfusion was measured before and after AVUS with contrast-enhanced ultrasound. Quantitative perfusion measures: perfusion index (PI) and peak enhancement (PE) were obtained from each AVUS dose. After high-dose AVUS, PE and PI decreased by an average of 58.1 ± 4.9% and 49.1 ± 6.5 % respectively. Conversely, following low dose AVUS, PE and PI increased from baseline by an average of 47.8 ± 4.5% % and 20.3 ± 2.4 %, respectively. The high-dose AVUS therapy decreased tumoral perfusion, an effect that could be used for noninvasive ischemic therapy. Conversely, low-dose therapy increased tumor perfusion, which may improve drug delivery or radiation therapy. These opposite therapy effects can support multiple roles for AVUS in cancer therapy by tunable modulation of blood flow in tumors.

Predictive Value of Abnormal Findings on Covered Transjugular Intrahepatic Portosystemic Shunt Baseline Doppler Sonography.

Doppler ultrasound (DUS) is frequently performed as a screening and diagnostic modality to evaluate the transjugular intrahepatic portosystemic shunt (TIPS) for short- and intermediate-term complications of the procedure. However, the clinical significance of initial frequently observed abnormalities in flow velocities, gradient, and direction in patients with covered TIPS is less studied. A retrospective study was performed between January 2005 and December 2014, and all patients undergoing covered TIPS procedure for the management of portal hypertension were included. Abnormal DUS findings were defined as intrashunt peak systolic velocities (PSVs) less than 90 or greater than 190 cm/s, intrashunt gradient greater than 50 cm/s, and abnormal flow direction in the main, right, and/or left portal veins. A total of 283 patients with adequate clinical follow-up and baseline TIPS DUS were included in the study. Median follow-up was 18.2 months. During the follow-up period, portal hypertension symptoms recurred in 83 patients who underwent TIPS angiography and/or revision. Of the 83, 57 had an elevated portosystemic gradient (>12 mm Hg) requiring angioplasty/stenting. With regard to baseline ultrasound, low PSVs were present in 88 patients (31.1%), high PSVs in 44 patients (15.5%), and elevated gradient in 98 patients (34.6%). The rate of developing TIPS stenosis in the future was not higher in patients with abnormal DUS parameters. For example, 26 (19.7%) of 132 patients with abnormal TIPS velocities developed stenosis compared with 31 (20.5%) of 151 patients with normal velocities (P = 0.9). Based on these results, abnormal DUS findings observed on baseline TIPS ultrasound examination have low predictive value for future covered TIPS dysfunction and failure.

Microbubble-enhanced ultrasound for the antivascular treatment and monitoring of hepatocellular carcinoma.

Background and Objective: Hepatocellular carcinoma (HCC) is the most common primary liver malignancy, and its current management relies heavily on locoregional therapy for curative therapy, bridge to transplant, and palliative therapy. Locoregional therapies include ablation and hepatic artery therapies such as embolization and radioembolization. In this study we evaluate the feasibility of using novel antivascular ultrasound (AVUS) as a noninvasive locoregional therapy to reduce perfusion in HCC lesions in a rat model and, monitor the effect with contrast-enhanced ultrasound imaging. Methods: HCC was induced in 36 Wistar rats by the ingestion of 0.01% diethylnitrosamine (DEN) for 12 weeks. Two therapy regimens of AVUS were evaluated. A primary regimen (n = 19) utilized 2-W/cm2, 3-MHz ultrasound (US) for 6 minutes insonation with 0.7 ml of microbubbles administered as an intravenous bolus. An alternate dose at half the primary intensity, sonication time, and contrast concentration was evaluated in 11 rats to assess the efficacy of a reduced dose. A control group (n = 6) received a sham therapy. Tumor perfusion was measured before and after AVUS with nonlinear contrast ultrasound (NLC) and power Doppler (PD). The quantitative perfusion measures included perfusion index (PI), peak enhancement (PE), time to peak (TTP), and perfusion area from NLC and PD scans. Total tumor area perfused during the scan was measured by a postprocessing algorithm called delta projection. Tumor histology was evaluated for signs of tissue injury and for vascular changes using CD31 immunohistochemistry. Results: DEN exposure induced autochthonous hepatocellular carcinoma lesions in all rats. Across all groups prior to therapy, there were no significant differences in the nonlinear contrast observations of peak enhancement and perfusion index. In the control group, there were no significant differences in any of the parameters after sham treatment. After the primary AVUS regimen, there were significant changes in all parameters (p ≤ 0.05) indicating substantial decreases in tumor perfusion. Peak enhancement in nonlinear contrast scans showed a 37.9% ± 10.1% decrease in tumor perfusion. Following reduced-dose AVUS, there were no significant changes in perfusion parameters, although there was a trend for the nonlinear contrast observations of peak enhancement and perfusion index to increase. Conclusion: This study translated low-intensity AVUS therapy into a realistic in vivo model of HCC and evaluated its effects on the tumor vasculature. The primary dose of AVUS tested resulted in significant vascular disruption and a corresponding reduction in tumor perfusion. A reduced dose of AVUS, on the other hand, was ineffective at disrupting perfusion but demonstrated the potential for enhancing tumor blood flow. Theranostic ultrasound, where acoustic energy and microbubbles are used to monitor the tumor neovasculature as well as disrupt the vasculature and treat lesions, could serve as a potent tool for delivering noninvasive, locoregional therapy for hepatocellular carcinoma.

B-mode ultrasound for the assessment of hepatic fibrosis: a quantitative multiparametric analysis for a radiomics approach.

Hepatic fibrosis and cirrhosis are a growing global health problem with increasing mortality rates. Early diagnosis and staging of hepatic fibrosis represent a major challenge. Currently liver biopsy is the gold standard for fibrosis assessment; however, biopsy requires an invasive procedure and is prone to sampling error and reader variability. In the current study we investigate using quantitative analysis of computer-extracted features of B-mode ultrasound as a non-invasive tool to characterize hepatic fibrosis. Twenty-two rats were administered diethylnitrosamine (DEN) orally for 12 weeks to induce hepatic fibrosis. Four control rats did not receive DEN. B-mode ultrasound scans sampling throughout the liver were acquired at baseline, 10, and 13 weeks. Computer extracted quantitative parameters representing brightness (echointensity, hepatorenal index) and variance (heterogeneity, anisotropy) of the liver were studied. DEN rats showed an increase in echointensity from 37.1 ± SD 7.8 to 53.5 ± 5.7 (10 w) to 57.5 ± 6.1 (13 w), while the control group remained unchanged at an average of 34.5 ± 4.5. The three other features studied increased similarly over time in the DEN group. Histologic analysis showed METAVIR fibrosis grades of F2-F4 in DEN rats and F0-F1 in controls. Increasing imaging parameters correlated with increasing METAVIR grades, and anisotropy showed the strongest correlation (ρ = 0.58). Sonographic parameters combined using multiparametric logistic regression were able to differentiate between clinically significant and insignificant fibrosis. Quantitative B-mode ultrasound imaging can be implemented in clinical settings as an accurate non-invasive tool for fibrosis assessment.

Incidence, determinants and outcomes of pregnancy-associated hepatitis B flares: A regional hospital-based cohort study.

BACKGROUND & AIMS: There is limited knowledge about hepatitis B virus (HBV) flare among pregnant women. We evaluated the incidence, determinants and outcomes of HBV flare in a multicultural cohort of pregnant HBV-infected women in the United States. METHODS: We performed a retrospective cohort study of pregnant hepatitis B surface antigen-positive women cared for at hospital-based clinics of 4 medical centres in Southeastern Pennsylvania from 2006 to 2015. The main outcome was incident HBV flare (alanine aminotransferase [ALT] ≥2 times upper limit of normal) during pregnancy or within 6 months after delivery. Among patients with flare, we determined development of jaundice (total bilirubin ≥2.5 mg/dL) and hepatic decompensation. Multivariable logistic regression was used to estimate odds ratios (ORs) of HBV flare for risk factors of interest, including timing of flare (during pregnancy versus post-delivery), nulliparity, younger age, HBV e antigen (HBeAg) status, and lack of anti-HBV therapy. RESULTS: Among 310 pregnant predominantly African HBV-infected women with 388 pregnancies, the incidence of HBV flare was 14% (95% CI, 10-18%) during pregnancy and 16% (95% CI, 11-24%) post-delivery. Jaundice developed in 12% and hepatic decompensation in 2%. Positive HBeAg was associated with HBV flare (OR, 2.55; 95% CI, 1.04-6.20). HBV DNA was measured in 55% of patients, and only 50% were referred for HBV specialty care. CONCLUSIONS: Pregnancy-associated hepatitis B flare occurred in 14% during pregnancy and 16% post-delivery and rarely led to hepatic decompensation. Positive HBeAg was the main risk factor identified. Women did not have adequate HBV monitoring or follow-up during pregnancy.