How to approach pancreatic cancer after neoadjuvant treatment: assessment of resectability using multidetector CT and tumor markers.

OBJECTIVES: To investigate clinical and CT factors associated with local resectability in patients with nonmetastatic pancreatic cancers after neoadjuvant chemotherapy ± radiation therapy (CRT). METHODS: This retrospective study included consecutive patients with nonmetastatic pancreatic cancers who underwent neoadjuvant CRT between June 2009 and June 2019. Tumor size, tumor-vascular contact with artery/vein, and local resectability categories (resectable, borderline resectable, or locally advanced) were assessed at baseline and post-CRT CT. Baseline and post-CRT carbohydrate antigen (CA) 19-9 levels were also assessed. Clinical or imaging features related to R0 resection were determined using logistic regression analysis. RESULTS: A total of 179 patients (mean age, 62.4 ± 9.3 years; 92 men) were included. After neoadjuvant CRT, 105 (58.7%) patients received R0 resection, while 74 (41.3%) did not. R0 resection rates were significantly different according to post-CRT CT resectability categories (p < 0.001): 82.8% (48/58), 70.1% (47/67), and 18.5% (10/54) for resectable, borderline resectable, and locally advanced disease, respectively. For post-CRT borderline resectable disease, ≥ 50% decrease in CA 19-9 was significantly associated with R0 resection (odds ratio (OR), 3.160; p = 0.02). For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm (OR, 9.668; p = 0.026) and decreased tumor-arterial contact (OR, 24.213; p = 0.022) were significantly associated with R0 resection. CONCLUSION: Post-CRT CT resectability categorization may be useful for the assessment of R0 resectability in patients with pancreatic cancer following neoadjuvant CRT. Additionally, ≥ 50% decrease in CA 19-9 was associated with R0 resection in post-CRT borderline resectable disease, while small post-CRT tumor size and decreased tumor-arterial contact were with locally advanced disease. KEY POINTS: • R0 resection rates following neoadjuvant chemotherapy ± radiation therapy (CRT) were 82.8%, 70.1%, and 18.5% in resectable, borderline resectable, and locally advanced disease, respectively, at post-CRT CT (p < 0.001). • For post-CRT borderline resectable disease, ≥ 50% decrease in carbohydrate antigen (CA) 19-9 was significantly associated with R0 resection. • For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm and decreased tumor-arterial contact were significantly associated with R0 resection.

Quantitative ultrasound radiofrequency data analysis for the assessment of hepatic steatosis using the controlled attenuation parameter as a reference standard.

PURPOSE: This study was aimed to investigate the value of quantitative ultrasound (US) parameters from radiofrequency (RF) data analysis for assessing hepatic steatosis, using controlled attenuation parameter (CAP)-based steatosis grades as the reference standard. METHODS: We analyzed 243 participants with both B-mode liver US with RF data acquisition and CAP measurements. On B-mode US images, hepatic steatosis was visually scored (0/1/2/3, none/mild/moderate/severe), and the hepatorenal index (HRI) was calculated. From the RF data analysis, the tissue scatter-distribution imaging parameter (TSI-p) and tissue attenuation imaging parameter (TAI-p) of the liver parenchyma were measured. US parameters were correlated with CAP-based steatosis grades (S0/1/2/3, none/mild/moderate/severe) and their diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. Multivariate linear regression analysis was performed to identify determinants of TSI-p and TAI-p. RESULTS: Participants were classified as having S0 (n=152), S1 (n=54), S2 (n=14), and S3 (n=23) on CAP measurements. TSI-p and TAI-p were significantly correlated with steatosis grades (ρ =0.593 and ρ=-0.617, P<0.001 for both). For predicting ≥S1, ≥S2, and S3, the areas under the ROC curves (AUCs) of TSI-p were 0.827/0.914/0.917; TAI-p, 0.844/0.914/0.909; visual scores, 0.659/0.778/0.794; and HRI, 0.629/0.751/0.759, respectively. TSI-p and TAI-p had significantly higher AUCs than did visual scores or HRI for ≥S1 or ≥S2 (P≤0.003). In the multivariate analysis, the transient elastography-based fibrosis grade (P=0.034) and steatosis grade (P<0.001) were independent determinants of TSI-p, while steatosis grade (P<0.001) was an independent determinant of TAI-p. CONCLUSION: TSI-p and TAI-p derived from US RF data may be useful for detecting hepatic steatosis and assessing its severity.

Validation of a New Point Shear-Wave Elastography Method for Noninvasive Assessment of Liver Fibrosis: A Prospective Multicenter Study.

OBJECTIVE: To validate the diagnostic value of a new point shear-wave elastography method, S-shearwave elastography (S-SWE; Samsung Medison Co., Ltd.), in noninvasive assessment of liver fibrosis. MATERIALS AND METHODS: In this prospective multicenter study, liver stiffness (LS) measurements for 600 participants were obtained with both S-SWE and transient elastography (TE). The rates of unsuccessful LS measurements in S-SWE and TE were compared, and correlations between S-SWE and TE measurements were assessed. In 107 patients with histologic reference data, the optimal LS cut-off values for predicting severe fibrosis and cirrhosis on S-SWE were determined using receiver operating characteristic (ROC) curve analysis. The LS cut-off values in S-SWE were then validated in 463 patients without histologic reference data by using TE values as the reference standard, and the sensitivity and specificity of the cut-off values for predicting severe fibrosis and cirrhosis were calculated. RESULTS: The frequency of unsuccessful LS measurements on TE (4.5%, 27/600) was significantly higher than that (0.7%, 4/600) on S-SWE (p < 0.001). LS measurements on S-SWE showed a significant correlation with TE values (r = 0.880, p < 0.001). In 107 patients with histological reference data, the areas under the ROC curves on S-SWE were 0.845 and 0.850, with optimal cut-offs of 7.0 kilopascals (kPa) and 9.7 kPa, for the diagnosis of severe fibrosis and cirrhosis, respectively. Using these cut-off values, S-SWE showed sensitivities of 92.9% and 97.4% and specificities of 89.5% and 83.1% in TE-based evaluations of severe fibrosis and cirrhosis, respectively. CONCLUSION: LS measurements on S-SWE were well correlated with those on TE. In addition, S-SWE provided good diagnostic performance for staging of hepatic fibrosis, with a lower rate of unsuccessful LS measurements compared with TE.

Prediction of Local Tumor Progression after Radiofrequency Ablation (RFA) of Hepatocellular Carcinoma by Assessment of Ablative Margin Using Pre-RFA MRI and Post-RFA CT Registration.

Objective: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. Materials and Methods: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (≥ 3 mm) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. Results: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). Conclusion: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

Major Stressors among Korean Adolescents According to Gender, Educational Level, Residential Area, and Socioeconomic Status.

Adolescents are exposed to many stressors which have been associated with poor mental health. Using data from the 2015 Korea Youth Risk Behavior Web-based Survey, we identified the major stressors among Korean adolescents based on gender, current educational level, residential area, and socioeconomic status (SES). The major stressors among girls were relationship- and appraisal-related factors, whereas boys more often reported health- and conflict-related factors. High school students more often reported academic performance and family circumstances as major stressors, whereas middle school students tended to report conflict-related factors. Urban adolescents reported academic performance and conflicts with parents as major stressors while rural adolescents reported conflicts with teachers and peer relationship problems. Finally, adolescents of lower SES reported multiple factors, including relational and family problems, as major stressors; contrarily, among those of higher SES, the primary stressor was uniquely related to academic performance. This result is significant in that adolescents' stress levels, as well as the types of major stressors, vary depending on individual factors. It could also be beneficial for developing and implementing individualized and thus more efficient stress-management strategies.

Preoperative MDCT Assessment of Resectability in Borderline Resectable Pancreatic Cancer: Effect of Neoadjuvant Chemoradiation Therapy.

OBJECTIVE: The purpose of this study is to evaluate the diagnostic performance of MDCT in assessing tumor resectability in patients with borderline resectable pancreatic cancers after receiving neoadjuvant chemoradiation therapy (CRT) in comparison with those undergoing upfront surgery. SUBJECTS AND METHODS: Thirty-seven patients with borderline resectable pancreatic cancers were randomly allocated to the neoadjuvant CRT group (arm 1; n = 18) or up-front surgery group (arm 2; n = 19). Three radiologists rated the likelihood of local resectability on a 5-point scale at preoperative MDCT in two separate sessions (session 1: post-CRT of arm 1, baseline of arm 2; session 2: using new imaging criteria reflecting the changes during CRT of arm 1). The AUC of each reviewer, as well as sensitivity, specificity, and accuracy based on consensus interpretation, were compared between arms and sessions. RESULTS: For local resectability (n = 30), AUC values at session 1 were 0.664, 0.669, and 0.588 for reviewers 1, 2, and 3, respectively, and were not significantly different between arms 1 (n = 15; 0.759, 0.713, and 0.593) and 2 (n = 15; 0.852, 0.685, and 0.722) (p > 0.05). In arm 1, MDCT sensitivity, specificity, accuracy were 22%, 100%, and 53%, respectively, at session 1 versus 78%, 67%, and 73%, respectively, at session 2 (p > 0.05). CONCLUSION: In patients with borderline resectable pancreatic cancers, neoadjuvant CRT did not significantly decrease the performance of MDCT for the prediction of local resectability. However, by considering post-CRT changes, such as nonprogression in tumor-vascular contact, MDCT may provide better sensitivity for locally resectable disease.

Preoperative tumor restaging and resectability assessment of gastric cancers after chemotherapy: diagnostic accuracy of MDCT using new staging criteria.

PURPOSE: To evaluate the diagnostic performance of preoperative MDCT for tumor restaging and determination of resectability in gastric cancers after chemotherapy using new staging criteria. METHODS: This retrospective study was approved by our institutional review board and the requirement for informed consent was waived. Thirty-seven patients with initially unresectable gastric cancers who had received chemotherapy followed by surgery were included. Two independent radiologists reviewed preoperative MDCT images to determine the TNM staging and rate the overall likelihood of resectability using a 5-point scale (5: definitely unresectable, 1: definitely resectable). New post-chemotherapy MDCT criteria do not use non-enhancing perigastric infiltrations, non-enhancing lymph nodes (LNs), and subtle remaining infiltrations after marked decrease in the size of distant metastases for T, N, and M upstaging, respectively. Discrepancies in TNM staging were resolved by a third reviewer. The diagnostic performances of MDCT were assessed using pathologic results or operation records as reference standards. RESULTS: For predicting resectability, the areas under the ROC curve were 0.885 and 0.882 (95% CIs 0.737-0.966 and 0.733-0.964) in reviewers 1 and 2, respectively, with substantial inter-reader agreement (weighted κ = 0.689). Sensitivities and specificities of MDCT for tumor restaging on a consensus review were 80.0% (4/5) and 100% (29/29) for T4b, 35.3% (6/17) and 81.3% (13/16) for N-positive, and 63.6% (7/11) and 100% (26/26) for M1, respectively. CONCLUSIONS: For gastric cancers after chemotherapy, new MDCT criteria demonstrated high specificities for T4b and M-staging and good performances to predict resectability before conversion surgery.

Preoperative Assessment of Pancreatic Cancer with FDG PET/MR Imaging versus FDG PET/CT Plus Contrast-enhanced Multidetector CT: A Prospective Preliminary Study.

Purpose To determine the diagnostic performance of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging in the preoperative assessment of pancreatic cancer in comparison with that of FDG PET/computed tomography (CT) plus contrast material-enhanced multidetector CT. Materials and Methods This prospective study was approved by the institutional review board; written informed consent was obtained. Thirty-seven patients with 39 pancreatic tumors underwent preoperative FDG PET/MR imaging, PET/CT, and contrast-enhanced multidetector CT. The authors measured maximal and mean standardized uptake values (SUVmax and SUVmean, respectively) of pancreatic cancer at PET/MR imaging and PET/CT. Two radiologists independently reviewed the two imaging sets (set 1, PET/MR imaging; set 2, PET/CT plus multidetector CT) to determine tumor resectability according to a five-point scale, N stage (N0 or N positive), and M stage (M0 or M1). With use of clinical-surgical-pathologic findings as the standard of reference (n = 20), diagnostic performances of the two imaging sets were compared by using the McNemar test. Results Both SUVmax and SUVmean of pancreatic tumors showed strong correlations between PET/MR imaging and PET/CT (r = 0.897 and 0.890, respectively; P < .001). The diagnostic performance of PET/MR imaging was not significantly different from that of PET/CT plus multidetector CT in the assessment of tumor resectability (area under the receiver operating characteristic curve: 0.891 vs 0.776, respectively, for reviewer 1 [P = .109] and 0.859 vs 0.797 for reviewer 2 [P = .561]), N stage (accuracy: 54% [seven of 13 patients] vs 31% [four of 13 patients]; P = .250 for both reviewers), and M stage (accuracy: 94% [16 of 17 patients] vs 88% [15 of 17 patients] for reviewer 1 [P > .999] and 94% [16 of 17 patients] vs 82% [14 of 17 patients] for reviewer 2 [P = .500]). Conclusion FDG PET/MR imaging showed a diagnostic performance similar to that of PET/CT plus contrast-enhanced multidetector CT in the preoperative evaluation of the resectability and staging of pancreatic tumors. © RSNA, 2016 Online supplemental material is available for this article.

MR elastography for noninvasive assessment of hepatic fibrosis: reproducibility of the examination and reproducibility and repeatability of the liver stiffness value measurement.

PURPOSE: To determine the reproducibility of MR elastography (MRE) and the reproducibility and repeatability of the stiffness measurement of MRE in the staging of liver fibrosis. MATERIALS AND METHODS: Ninety-four patients, who underwent liver MRE, were included in this study. The patients were classified into group 1 (n = 47) and group 2 (n = 47) according to our knowledge of their histologic hepatic fibrosis (HF) stage. To analyze the reproducibility of MRE, the group 1 patients underwent MRE twice. In addition, to evaluate the repeatability and reproducibility of the stiffness measurement of MRE, a single observer measured the stiffness values of the second MREs in group 1 twice, and two observers independently measured the stiffness values of MRE in group 2. A 95% Bland-Altman limits of agreement and intraclass correlation coefficients (ICCs) were used to evaluate the reproducibility and repeatability of MRE. RESULTS: In group I, there was no significant difference in the mean liver stiffness values of the first and second MRE examinations, i.e., 3.45 ± 0.25 kPa vs. 3.35 ± 0.23 kPa (p = 0.22). The reproducibility of the MRE examination and the reproducibility and repeatability of the stiffness measurement were high, i.e., the ICCs of each parameter were 0.945, 0.827, and 0.963, respectively, and the 95% limits of agreement were 25.3%, 35.35%, and 18.0%, respectively. CONCLUSION: MRE is a promising tool for evaluating HF and has high reproducibility of the examination as well as reproducibility and repeatability of the stiffness measurements.

Adaptive statistical iterative reconstruction and Veo: assessment of image quality and diagnostic performance in CT colonography at various radiation doses.

OBJECTIVES: To evaluate the diagnostic performance of computed tomography (CT) colonography (CTC) reconstructed with different levels of adaptive statistical iterative reconstruction (ASiR, GE Healthcare) and Veo (model-based iterative reconstruction, GE Healthcare) at various tube currents in detection of polyps in porcine colon phantoms. METHODS: Five porcine colon phantoms with 46 simulated polyps were scanned at different radiation doses (10, 30, and 50 mA s) and were reconstructed using filtered back projection (FBP), ASiR (20%, 40%, and 60%) and Veo. Eleven data sets for each phantom (10-mA s FBP, 10-mA s 20% ASiR, 10-mA s 40% ASiR, 10-mA s 60% ASiR, 10-mA s Veo, 30-mA s FBP, 30-mA s 20% ASiR, 30-mA s 40% ASiR, 30-mA s 60% ASiR, 30-mA s Veo, and 50-mA s FBP) yielded a total of 55 data sets. Polyp detection sensitivity and confidence level of 2 independent observers were evaluated with the McNemar test, the Fisher exact test, and receiver operating characteristic curve analysis. Comparative analyses of overall image quality score, measured image noise, and interpretation time were also performed. RESULTS: Per-polyp detection sensitivities and specificities were highest in 10-mA s Veo, 30-mA s FBP, 30-mA s 60% ASiR, and 50-mA s FBP (sensitivity, 100%; specificity, 100%). The area-under-the-curve values for the overall performance of each data set was also highest (1.000) at 50-mA s FBP, 30-mA s FBP, 30-mA s 60% ASiR, and 10-mA s Veo. Images reconstructed with ASiR showed statistically significant improvement in per-polyp detection sensitivity as the percent level of per-polyp sensitivity increased (10-mA s FBP vs 10-mA s 20% ASiR, P = 0.011; 10-mA s FBP vs 10-mA s 40% ASiR, P = 0.000; 10-mA s FBP vs 10-mA s 60% ASiR, P = 0.000; 10-mA s 20% ASiR vs 40% ASiR, P = 0.034). Overall image quality score was highest at 30-mA s Veo and 50-mA s FBP. The quantitative measurement of the image noise was lowest at 30-mA s Veo and second lowest at 10-mA s Veo. There was a trend of decrease in time required for image interpretation as the percent level of ASiR increased, and ASiR or Veo was used instead of FBP. However, differences from comparative analyses of overall image quality score, measured image noise, and interpretation time did not reach statistical significance. CONCLUSION: ASiR and Veo showed improved diagnostic performance with excellent sensitivity and specificity with less image noise and good image quality compared with FBP reconstruction of same radiation dose. Our study confirmed feasibility of low-dose CTC with iterative reconstruction as a promising screening tool with excellent diagnostic performance similar to that of the standard-dose CTC with FBP.