Purpose Sonic hedgehog (SHH), an activating ligand of smoothened (SMO), is overexpressed in > 70% of pancreatic cancers (PCs). We investigated the impact of vismodegib, an SHH antagonist, plus gemcitabine (GV) or gemcitabine plus placebo (GP) in a multicenter phase Ib/randomized phase II trial and preclinical PC models. Patients and Methods Patients with PC not amenable to curative therapy who had received no prior therapy for metastatic disease and had Karnofsky performance score ≥ 80 were enrolled. Patients were randomly assigned in a one-to-one ratio to GV or GP. The primary end point was progression-free-survival (PFS). Exploratory correlative studies included serial SHH serum levels and contrast perfusion computed tomography imaging. To further investigate putative biologic mechanisms of SMO inhibition, two autochthonous pancreatic cancer models (KrasG12D; p16/p19fl/fl; Pdx1-Cre and KrasG12D; p53R270H/wt; Pdx1-Cre) were studied. Results No safety issues were identified in the phase Ib portion (n = 7)...

https://ascopubs.org/doi/pdfdirect/10.1200/JCO.2015.62.8719

Randomized Phase Ib/II Study of Gemcitabine Plus Placebo or Vismodegib, a Hedgehog Pathway Inhibitor, in Patients With Metastatic Pancreatic Cancer

On the basis of a thorough examination, contrast agent–enhanced multidetector CT allows the diagnosis of primary acute mesenteric ischemia with high sensitivity and specificity; thus, it may be used as the first-line imaging method.

https://pubs.rsna.org/doi/pdf/10.1148/radiol.10091938

Diagnostic Accuracy of Multidetector CT in Acute Mesenteric Ischemia: Systematic Review and Meta-Analysis

OBJECTIVE. This article summarizes the current status of CT perfusion in oncologic imaging, including lesion characterization, staging, prediction of patient outcome or response to therapy, assessment of response to different therapies, and evaluation of tumor relapse. Technical limitations and drawbacks of CT perfusion are also discussed. CONCLUSION. Tumor angiogenesis is essential for cancer growth and provides an attractive target for oncologic therapies. CT perfusion is an emerging imaging tool that provides both qualitative and quantitative information regarding tumor angiogenesis.

https://www.ajronline.org/doi/pdf/10.2214/AJR.11.8476

CT Perfusion in Oncologic Imaging: A Useful Tool?

Dynamic first-pass area-detector perfusion CT has the potential to be more specific and accurate than integrated fluorine 18 fluorodeoxyglucose PET/CT for differentiation of malignant and benign pulmonary nodules.

Differentiation of malignant and benign pulmonary nodules with quantitative first-pass 320-detector row perfusion CT versus FDG PET/CT.

CT Angiography: Current Technology and Clinical Use

The purpose of this study was to evaluate a whole-organ perfusion protocol of the pancreas in patients with primary pancreas carcinoma and to analyse perfusion differences between normal and diseased pancreatic tissue. Thirty patients with primary pancreatic malignancy were imaged on a 320-slice CT unit. Twenty-nine cancers were histologically proven. CT data acquisition was started manually after contrast-material injection (8 ml/s, 350 mg iodine/ml) and dynamic density measurements in the right ventricle. After image registration, perfusion was determined with the gradient-relationship technique and volume regions-of-interest were defined for perfusion measurements. Contrast time-density curves and perfusion maps were generated. Statistical analysis was performed using the Kolmogorov-Smirnov test for analysis of normal distribution and Kruskal-Wallis test (nonparametric ANOVA) with Bonferroni correction for multiple stacked comparisons. In all 30 patients the entire pancreas was imaged, and registration could be completed in all cases. Perfusion of pancreatic carcinomas was significantly lower than of normal pancreatic tissue (P < 0.001) and could be visualized on colored perfusion maps. The 320-slice CT allows complete dynamic visualization of the pancreas and enables calculation of whole-organ perfusion maps. Perfusion imaging carries the potential to improve detection of pancreatic cancers due to the perfusion differences.

Whole-organ perfusion of the pancreas using dynamic volume CT in patients with primary pancreas carcinoma: acquisition technique, post-processing and initial results.

Purpose We sought to compare the performance of 3 computer-aided detection (CAD) polyp algorithms in computed tomography colonography (CTC) with fecal tagging. Methods CTC data sets of 33 patients were retrospectively analysed by 3 different CAD systems: system 1, MedicSight; system 2, Colon CAD; and system 3, Polyp Enhanced View. The polyp database comprised 53 lesions, including 6 cases of colorectal cancer, and was established by consensus reading and comparison with colonoscopy. Lesions ranged from 6-40 mm, with 25 lesions larger than 10 mm in size. Detection and false-positive (FP) rates were calculated. Results CAD systems 1 and 2 could be set to have varying sensitivities with higher FP rates for higher sensitivity levels. Sensitivities for system 1 ranged from 73%–94% for all lesions (78%–100% for lesions ≥10 mm) and, for system 2, from 64%–94% (78%–100% for lesions ≥10 mm). System 3 reached an overall sensitivity of 76% (100% for lesions ≥10 mm). The mean FP rate per patient ranged from 8–32 for system 1, from 1–8 for system 2, and was 5 for system 3. At the highest sensitivity level for all polyps (94%), system 2 showed a statistically significant lower FP rate compared with system 1 ( P = .001). When analysing lesions ≥10 mm, system 3 had significantly fewer FPs than systems 1 and 2 ( P Conclusions Standalone CTC-CAD analysis in the selected patient collective showed the 3 systems tested to have a variable but overall promising performance with respect to sensitivity and the FP rate.

Computer-aided Detection in Computed Tomography Colonography with Full Fecal Tagging: Comparison of Standalone Performance of 3 Automated Polyp Detection Systems

Purpose: We sought to compare the performance of 3 computer-aided detection (CAD) polyp algorithms in computed tomography colonography (CTC) with fecal tagging. Methods: CTC data sets of 33 patients were retrospectively analysed by 3 different CAD systems: system 1, MedicSight; system 2, Colon CAD; and system 3, Polyp Enhanced View. The polyp database comprised 53 lesions, including 6 cases of colorectal cancer, and was established by consensus reading and comparison with colonoscopy. Lesions ranged from 6-40 mm, with 25 lesions larger than 10 mm in size. Detection and false-positive (FP) rates were calculated. Results: CAD systems 1 and 2 could be set to have varying sensitivities with higher FP rates for higher sensitivity levels. Sensitivities for system 1 ranged from 73%e94% for all lesions (78%e100% for lesions � 10 mm) and, for system 2, from 64%e94% (78%e100% for lesions � 10 mm). System 3 reached an overall sensitivity of 76% (100% for lesions � 10 mm). The mean FP rate per patient ranged from 8e 32 for system 1, from 1e8 for system 2, and was 5 for system 3. At the highest sensitivity level for all polyps (94%), system 2 showed a statistically significant lower FP rate compared with system 1 (P ¼ .001). When analysing lesions � 10 mm, system 3 had significantly fewer FPs than systems 1 and 2 (P < .012). Conclusions: Standalone CTC-CAD analysis in the selected patient collective showed the 3 systems tested to have a variable but overall promising performance with respect to sensitivity and the FP rate.

Abdominal Imaging / Imagerie abdominale Computer-aided Detection in Computed Tomography Colonography with Full Fecal Tagging: Comparison of Standalone Performance of 3 Automated Polyp Detection Systems

Poster: "ECR 2010 / C-1379 / Radiofrequency ablation of renal masses: Mid-term results" by: "C. Kloeters1, U. Kauder2, S. Kandel1, M. Johannsen2, P. Rogalla1; 1Toronto, ON/CA, 2Berlin/DE"

Sonja Kandel

Papers

Whole-organ perfusion of the pancreas using dynamic volume CT in patients with primary pancreas carcinoma: acquisition technique, post-processing and initial results.

Computer-aided Detection in Computed Tomography Colonography with Full Fecal Tagging: Comparison of Standalone Performance of 3 Automated Polyp Detection Systems

Abdominal Imaging / Imagerie abdominale Computer-aided Detection in Computed Tomography Colonography with Full Fecal Tagging: Comparison of Standalone Performance of 3 Automated Polyp Detection Systems

Radiofrequency ablation of renal masses: Mid-term results