Chung Y. Nio

Preoperative biliary drainage for cancer of the head of the pancreas

BACKGROUND The benefits of preoperative biliary drainage, which was introduced to improve the postoperative outcome in patients with obstructive jaundice caused by a tumor of the pancreatic head, are unclear. METHODS In this multicenter, randomized trial, we compared preoperative biliary drainage with surgery alone for patients with cancer of the pancreatic head. Patients with obstructive jaundice and a bilirubin level of 40 to 250 micromol per liter (2.3 to 14.6 mg per deciliter) were randomly assigned to undergo either preoperative biliary drainage for 4 to 6 weeks, followed by surgery, or surgery alone within 1 week after diagnosis. Preoperative biliary drainage was attempted primarily with the placement of an endoprosthesis by means of endoscopic retrograde cholangiopancreatography. The primary outcome was the rate of serious complications within 120 days after randomization. RESULTS We enrolled 202 patients; 96 were assigned to undergo early surgery and 106 to undergo preoperative biliary drainage; 6 patients were excluded from the analysis. The rates of serious complications were 39% (37 patients) in the early-surgery group and 74% (75 patients) in the biliary-drainage group (relative risk in the early-surgery group, 0.54; 95% confidence interval [CI], 0.41 to 0.71; P<0.001). Preoperative biliary drainage was successful in 96 patients (94%) after one or more attempts, with complications in 47 patients (46%). Surgery-related complications occurred in 35 patients (37%) in the early-surgery group and in 48 patients (47%) in the biliary-drainage group (relative risk, 0.79; 95% CI, 0.57 to 1.11; P=0.14). Mortality and the length of hospital stay did not differ significantly between the two groups. CONCLUSIONS Routine preoperative biliary drainage in patients undergoing surgery for cancer of the pancreatic head increases the rate of complications. (Current Controlled Trials number, ISRCTN31939699.)

Disappointing interobserver agreement among radiologists for a classifying diagnosis of pancreatic cysts using magnetic resonance imaging

Objectives To assess the degree of interobserver agreement of MRI in the diagnostic assessment of pancreatic cysts (PCs). Methods Magnetic resonance imaging sets of images of 62 patients with PCs (32 with histological confirmation and 30 with clinical diagnosis) were reviewed by 4 experienced radiologists. Features scored included septations, nodules, solid components, pancreatic duct communication, and wall thickening (>2 mm). Radiologists were asked whether they considered the PC mucinous and if the PC was suspicious for malignancy. Furthermore, they had to choose a classifying diagnosis. Intraclass correlation coefficient (ICC) was used to measure agreement within the group. Results Interobserver agreement for septations and nodules was fair (ICC, 0.36 and 0.23, respectively). Agreement for the presence of solid components was fair (ICC, 0.23), agreement for communication with the pancreatic duct was moderate (ICC, 0.53), and agreement for wall thickening was moderate (ICC, 0.44). There was fair agreement for the discrimination between mucinous and nonmucinous PC (ICC, 0.36). Agreement was fair (ICC, 0.26) for a classifying diagnosis and fair for the presence of malignant features (ICC, 0.33). Conclusions Interobserver agreement was poor to moderate for individual PC features, and there was fair agreement for a classifying diagnosis. Magnetic resonance imaging morphology alone did not allow for a reliable discrimination between different types of PC.

CT-Colonography vs. Colonoscopy for Detection of High-Risk Sessile Serrated Polyps.

Objectives:Sessile serrated polyps (SSPs) are suggested to be the precursors of 15–30% of all colorectal cancers (CRCs). Therefore, CRC screening modalities should also be designed to detect high-risk SSPs. We compared computed tomography colonography (CTC) with colonoscopy-based screening for the detection of high-risk SSPs in average-risk individuals.Methods:Data from a randomized controlled trial that compared CTC with colonoscopy for population screening were used for the analysis. Individuals diagnosed at CTC with a lesion ≥10 mm in size were referred for colonoscopy. Individuals with only 6–9 mm lesions were offered surveillance CTC. This surveillance CTC was followed by a colonoscopy when a lesion ≥6 mm was detected. Yield of both was accumulated to mimic current American College of Radiology CTC referral strategy (referral of individuals with any lesion ≥6 mm). Per participant detection of ≥1 high-risk (dysplastic and/or ≥10 mm) SSP was compared with colonoscopy using multiple logistic regression analysis.Results:In total, 8,844 individuals were invited to participate (in 2:1 allocation), of which 1,276 colonoscopy and 982 CTC invitees participated in the study. In the colonoscopy arm, 4.3% of individuals were diagnosed with ≥1 high-risk SSP, compared with 0.8% in the CTC arm (odds ratio (OR) 5.5; 95% confidence interval (CI) 2.6–11.6; P<0.001). In total, 3.1% of individuals in the colonoscopy arm were diagnosed with high-risk SSPs as most advanced lesion, compared with 0.4% in the CTC arm (OR 7.7; 95% CI 2.7–21.6; P<0.001). The current CTC strategy showed a marked lower detection for especially flat high-risk SSPs (17 vs. 0), high-risk SSP located in the proximal colon (32 vs. 1), and SSPs with dysplasia (30 vs. 1).Conclusions:In a randomized controlled setting, the detection rate of high-risk SSPs was significantly higher with colonoscopy than CTC. These results might have implications for CTC as a CRC modality for opportunistic screening in average-risk adults.

Lesion Conspicuity and Efficiency of CT Colonography with Electronic Cleansing Based on a Three-Material Transition Model

OBJECTIVE The purpose of this article is to report the effect on lesion conspicuity and the practical efficiency of electronic cleansing for CT colonography (CTC). MATERIALS AND METHODS Patients were included from the Walter Reed Army Medical Center public database. All patients had undergone extensive bowel preparation with fecal tagging. A primary 3D display method was used. For study I, the data consisted of all patients with polyps > or = 6 mm. Two experienced CTC observers (observer 1 and observer 2) scored the lesion conspicuity considering supine and prone positions separately. For study II, data consisted of 19 randomly chosen patients from the database. The same observers evaluated the data before and after electronic cleansing. Evaluation time, assessment effort, and observer confidence were recorded. RESULTS In study I, there were 59 lesions partly or completely covered by tagged material (to be uncovered by electronic cleansing) and 70 lesions surrounded by air (no electronic cleansing required). The conspicuity did not differ significantly between lesions that were uncovered by electronic cleansing and lesions surrounded by air (observer 1, p < 0.5; observer 2, p < 0.6). In study II, the median evaluation time per patient after electronic cleansing was significantly shorter than for original data (observer 1, 20 reduced to 12 minutes; observer 2, 17 reduced to 12 minutes). Assessment effort was significantly smaller for both observers (p < 0.0000001), and observer confidence was significantly larger (observer 1, p < 0.007; observer 2, p < 0.0002) after electronic cleansing. CONCLUSION Lesions uncovered by electronic cleansing have comparable conspicuity with lesions surrounded by air. CTC with electronic cleansing sustains a shorter evaluation time, lower assessment effort, and larger observer confidence than without electronic cleansing.

Expiration-Phase Template-Based Motion Correction of Free-Breathing Abdominal Dynamic Contrast Enhanced MRI

This paper studies a novel method to compensate for respiratory and peristaltic motions in abdominal dynamic contrast enhanced magnetic resonance imaging. The method consists of two steps: 1) expiration-phase “template” construction and retrospective gating of the data to the template; and 2) nonrigid registration of the gated volumes. Landmarks annotated by three experts were used to directly assess the registration performance. A tri-exponential function fit to time intensity curves from regions of interest was used to indirectly assess the performance. One of the parameters of the tri-exponential fit was used to quantify the contrast enhancement. Our method achieved a mean target registration error (MTRE) of 2.12, 2.27, and 2.33 mm with respect to annotations by expert, which was close to the average interobserver variability (2.07 mm). A state-of-the-art registration method achieved an MTRE of 2.83-3.10 mm. The correlation coefficient of the contrast enhancement parameter to the Crohns disease endoscopic index of Severity (r = 0.60, p = 0.004) was higher than the correlation coefficient for the relative contrast enhancement measurements values of two observers (r(Observer1) = 0.29, p = 0.2; r(Observer2) = 0.45, p = 0.04). Direct and indirect assessments show that the expiration-based gating and a nonrigid registration approach effectively corrects for respiratory motion and peristalsis. The method facilitates improved enhancement measurement in the bowel wall in patients with Crohns disease.

Preoperative computed tomography assessment of skeletal muscle mass is valuable in predicting outcomes following hepatectomy for perihilar cholangiocarcinoma

BACKGROUND Liver surgery for perihilar cholangiocarcinoma (PHC) is associated with high rates of morbidity and mortality. OBJECTIVES This study investigated the impact of low skeletal muscle mass on short- and longterm outcomes following hepatectomy for PHC. METHODS Patients included underwent liver surgery for PHC between 1998 and 2013. Total skeletal muscle mass was measured at the level of the third lumbar vertebra using available preoperative computed tomography images. Sex-specific cut-offs for low skeletal muscle mass were determined by optimal stratification. RESULTS In 100 patients, low skeletal muscle mass was present in 42 (42.0%) subjects. The rate of postoperative complications (Clavien-Dindo Grade III and higher) was greater in patients with low skeletal muscle mass (66.7% versus 48.3%; multivariable adjusted P = 0.070). Incidences of sepsis (28.6% versus 5.2%) and liver failure (35.7% versus 15.5%) were increased in patients with low skeletal muscle mass. In addition, 90-day mortality was associated with low skeletal muscle mass in univariate analysis (28.6% versus 8.6%; P = 0.009). Median overall survival was shorter in patients with low muscle mass (22.8 months versus 47.5 months; P = 0.014). On multivariable analysis, low skeletal muscle mass remained a significant prognostic factor (hazard ratio 2.02; P = 0.020). CONCLUSIONS Low skeletal muscle mass has a negative impact on postoperative mortality and overall survival following resection of PHC and should therefore be considered in preoperative risk assessment.

Influence of Tagged Fecal Material on Detectability of Colorectal Polyps at CT: Phantom Study

OBJECTIVE The purpose of this study was to determine the influence of tagged material on the minimal radiation dose needed to detect colorectal polyps at CT. MATERIALS AND METHODS The study was conducted in two phases. In the first, three experienced observers determined the visibility of sessile polyps (6 mm) at five contrast levels (300, 480, 790, and 1,040 HU and air) and five tube charge levels (10, 14, 20, 28, and 40 mAs) in an anthropomorphic phantom. Each polyp was present in one of eight possible locations. The mean tube charge threshold for 90% correct responses was determined for each contrast level. Blinded observers performed independent 2D readings. In the second phase of the study, three 150-cm virtual colons were evaluated at two contrast levels (300 and 480 HU) and at five tube charge levels between 20 and 80 mAs. The three colons contained 18 randomly located polyps. The mean tube charge threshold for 90% sensitivity was determined for each contrast level. RESULTS In the first phase of the study, the estimated tube charge thresholds for 300, 480, and 790 HU were 24.0, 16.3, and 6.2 mAs. At 1,040 HU and in air, all polyps were detected at the lowest tube charge setting (10 mAs). In the second phase, the tube charge thresholds for 90% sensitivity at 300 and 480 HU were 70 and 35 mAs, respectively. CONCLUSION If polyps are covered by fecal material, a considerably higher tube charge setting is needed for adequate visualization than is needed for polyps in a completely cleansed colon, especially when the density of the tagged residue is low.

Validation of the Mayo Clinic Staging System in Determining Prognoses of Patients With Perihilar Cholangiocarcinoma

BACKGROUND & AIMS: Most systems for staging perihilar cholangiocarcinoma (PHC) have been developed for the minority of patients with resectable disease. The recently developed Mayo Clinic system for staging PHC requires only clinical and radiologic variables, but has not yet been validated. We performed a retrospective study to validate the Mayo Clinic staging system. METHODS: We identified consecutive patients with suspected PHC who were evaluated and treated at 2 tertiary centers in The Netherlands, from January 2002 through December 2014. Baseline characteristics (performance status, carbohydrate antigen 19‐9 level) used in the staging system were collected from medical records and imaging parameters (tumor size, suspected vascular involvement, and metastatic disease) were reassessed by 2 experienced abdominal radiologists. Overall survival was analyzed using the Kaplan–Meier method and comparison of staging groups was performed using the log‐rank test and Cox proportional hazard regression analysis. Discriminative performance was quantified by the concordance index and compared with the radiologic TNM staging of the American Joint Committee on Cancer (7th ed). RESULTS: PHCs from 600 patients were staged according to the Mayo Clinic model (23 stage I, 80 stage II, 357 stage III, and 140 stage IV). The median overall survival time was 11.6 months. The median overall survival times for patients with stages I, II, III, and IV were 33.2 months, 19.7 months, 12.1 months, and 6.0 months, respectively; with hazard ratios of 1.0 (reference), 2.02 (95% confidence interval [CI], 1.14–3.58), 2.71 (95% CI, 1.59–4.64), and 4.00 (95% CI, 2.30–6.95), respectively (P < .001). The concordance index score was 0.59 for the entire cohort (95% CI, 0.56–0.61). The Mayo Clinic model performed slightly better than the radiologic American Joint Committee on Cancer TNM system. CONCLUSIONS: In a retrospective study of 600 patients with PHC, we validated the Mayo Clinic system for staging PHC. This 4‐tier staging system may aid clinicians in making treatment decisions, such as referral for surgery, and predicting survival times.

Clinical outcomes and prevalence of cancer in patients with possible groove pancreatitis.

Data on non‐surgical treatment of groove pancreatitis (GP) and the risk of cancer are lacking. We aimed to determine the prevalence and predictors of cancer in patients in whom the diagnosis GP was considered, and to evaluate symptom improvement after treatment.

A Randomized Controlled Trial Comparing Participation and Diagnostic Yield in Colonoscopy and CT-Colonography for Population Based Colorectal Cancer Screening

Background: Semi-quantitative immunochemical fecal occult blood tests (I-FOBT) are increasingly used for colorectal cancer (CRC) screening. Their true performance characteristics have been determined clinically or sometimes by colonoscopy as “gold standard”. However, occasionally colonoscopy has false-negative results for CRC & Cancer Registry follow-up can provide information relevant to both tests. Aims: Evaluate true performance characteristics of both I-FOBT & colonoscopy examinations for detecting CRC & advanced adenomatous polyps (AAP). Methods: We reanalyzed a published file of ambulatory colonoscopy patients who also prepared 3 I-FOBTs processed by OC-MICRO automated instrument (Eiken, Tokyo, Japan) with ≥50ngHb/mL buffer in any test determining positivity (Rozen P, et al Cancer 2010). These patients were followed through the Israel National Cancer Registry (INCR) to identify newly diagnosed CRC. Analyses of sensitivities for CRC & AAP refer to results of I-FOBTs & initial colonoscopy. Results: 1630 persons performed both IFOBT & total colonoscopy, mean age 62.7 years, SD 11.9 & 50.1% males. They were followed through the INCR for mean 44.3 months SD13.4 & during this period 25 CRC patients were identified, 41% in the proximal colon & 86% were Stages 1 or 2. Follow-up Data Within 12 months both colonoscopy & I-FOBTs identified 21/22 CRCs, 2 initially classified as AAPs; neither test identified a Stage 1 rectal CRC. Between 12-24 months 2 more CRCs were diagnosed, both had elevated I-FOBTs & initially been identified as AAPs. Between 25-48 months a CRC was diagnosed after 47 months, it did not have elevated IFOBT & initially been identified as AAP. Analyses: At 1 year, sensitivity for CRC by both I-FOBT & initial colonoscopy was 95.5% (95%CI 86.8, 104) & at 24 months & 36 months it was 95.8% (95%CI 87.8, 104). Within 48 months sensitivity for CRC by I-FOBT was 92% (95%CI 81.4, 103) & 96% by colonoscopy. At 1 year 121 patients were identified as having AAPs, I-FOBT was positive in 70, & so had a sensitivity of 63.6% (95%CI 55.8, 71.5) for all significant neoplasms, CRC or AAP. At 24 months I-FOBT had a sensitivity of 63.2% (95%CI 55.8, 71.5) for all significant neoplasms. Conclusions: In this population, neither initial colonoscopy nor I-FOBTs identified all CRC patients. I-FOBTs examined at 50ngHb/mL buffer threshold identified almost all CRC diagnosed within 36 months. Colonoscopy identified most significant neoplasms, but only by clinical follow-up & repeated colonoscopy were AAPs reclassified correctly as CRCs. From this small but carefully documented study, it would be appropriate to repeat I-FOBTs after 1 year so as to identify any CRC missed initially by either test.