The Role of Dual-Phase Cone-Beam CT in Predicting Short-Term Response after Transarterial Chemoembolization for Hepatocellular Carcinoma.

PURPOSE: To identify computational and qualitative features derived from dual-phase cone-beam CT that predict short-term response in patients undergoing transarterial chemoembolization for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This retrospective study included 43 patients with 59 HCCs. Six features were extracted, including intensity of tumor enhancement on both phases and characteristics of the corona on the washout phase. Short-term response was evaluated by modified Response Evaluation Criteria in Solid Tumors on follow-up imaging, and extracted features were correlated to response using univariate and multivariate analyses. RESULTS: Univariate and multivariate analyses did not reveal a correlation between absolute and relative tumor enhancement characteristics on either phase with response (arterial P = .21; washout P = .40; ∆ P = .90). On multivariate analysis of qualitative characteristics, the presence of a diffuse corona was an independent predictor of incomplete response (P = .038) and decreased the odds ratio of objective response by half regardless of tumor size. CONCLUSIONS: Computational features extracted from contrast-enhanced dual-phase cone-beam CT are not prognostic of response to transarterial chemoembolization in patients with HCC. HCCs that demonstrate a diffuse, patchy corona have reduced odds of achieving complete response after transarterial chemoembolization and should be considered for additional treatment with an alternative modality.

Accuracy of flat panel detector CT with integrated navigational software with and without MR fusion for single-pass needle placement.

PURPOSE: Fluoroscopic systems in modern interventional suites have the ability to perform flat panel detector CT (FDCT) with navigational guidance. Fusion with MR allows navigational guidance towards FDCT occult targets. We aim to evaluate the accuracy of this system using single-pass needle placement in a deep brain stimulation (DBS) phantom. MATERIALS AND METHODS: MR was performed on a head phantom with DBS lead targets. The head phantom was placed into fixation and FDCT was performed. FDCT and MR datasets were automatically fused using the integrated guidance system (iGuide, Siemens). A DBS target was selected on the MR dataset. A 10 cm, 19 G needle was advanced by hand in a single pass using laser crosshair guidance. Radial error was visually assessed against measurement markers on the target and by a second FDCT. Ten needles were placed using CT-MR fusion and 10 needles were placed without MR fusion, with targeting based solely on FDCT and fusion steps repeated for every pass. RESULTS: Mean radial error was 2.75±1.39 mm as defined by visual assessment to the centre of the DBS target and 2.80±1.43 mm as defined by FDCT to the centre of the selected target point. There were no statistically significant differences in error between MR fusion and non-MR guided series. CONCLUSIONS: Single pass needle placement in a DBS phantom using FDCT guidance is associated with a radial error of approximately 2.5-3.0 mm at a depth of approximately 80 mm. This system could accurately target sub-centimetre intracranial lesions defined on MR.

Involvement of oxidative stress and caspase 2-mediated intrinsic pathway signaling in age-related increase in muscle cell apoptosis in mice.

Apoptosis has been implicated as a mechanism of loss of muscle cells in normal aging and plays an important role in age-related sarcopenia. To test the hypothesis that caspase 2 and c-Jun NH(2)-terminal kinase (JNK)-mediated intrinsic pathway signaling contribute to skeletal muscle cell apoptosis in aging, we compared activation of caspase 2 and JNK and the in vivo expression of 4-hydroxynonenal protein adducts (4-HNE), inducible nitric oxide synthase (iNOS), glucose-6-phosphate dehydrogenase (G6PDH), B-cell lymphoma-2 (BCL-2), BAX, and phospho-BCL-2 in gastrocnemius muscles of young (5 months old) and old (25 months old) mice. A distinct age-related increase in 4-HNE and iNOS expression was readily detected in mice. Increased oxidative stress and iNOS induction were further accompanied by a decrease in G6PDH expression, activation of caspase 2 and JNK, and inactivation of BCL-2 through phosphorylation at serine 70, and caspase 9 activation. Regression analysis further revealed that increased muscle cell death in aging was significantly correlated with changes in the levels of these molecules. Taken together, our data indicate that caspase 2 and JNK-mediated intrinsic pathway signaling is one of the mechanisms involved in age-related increase in muscle cell apoptosis.