Cascaded compression of size distribution of nanopores in monolayer graphene.

Monolayer graphene with nanometre-scale pores, atomically thin thickness and remarkable mechanical properties provides wide-ranging opportunities for applications in ion and molecular separations1, energy storage2 and electronics3. Because the performance of these applications relies heavily on the size of the nanopores, it is desirable to design and engineer with precision a suitable nanopore size with narrow size distributions. However, conventional top-down processes often yield log-normal distributions with long tails, particularly at the sub-nanometre scale4. Moreover, the size distribution and density of the nanopores are often intrinsically intercorrelated, leading to a trade-off between the two that substantially limits their applications5-9. Here we report a cascaded compression approach to narrowing the size distribution of nanopores with left skewness and ultrasmall tail deviation, while keeping the density of nanopores increasing at each compression cycle. The formation of nanopores is split into many small steps, in each of which the size distribution of all the existing nanopores is compressed by a combination of shrinkage and expansion and, at the same time as expansion, a new batch of nanopores is created, leading to increased nanopore density by each cycle. As a result, high-density nanopores in monolayer graphene with a left-skewed, short-tail size distribution are obtained that show ultrafast and ångström-size-tunable selective transport of ions and molecules, breaking the limitation of the conventional log-normal size distribution9,10. This method allows for independent control of several metrics of the generated nanopores, including the density, mean diameter, standard deviation and skewness of the size distribution, which will lead to the next leap in nanotechnology.

Ultralow contact resistance between semimetal and monolayer semiconductors.

Advanced beyond-silicon electronic technology requires both channel materials and also ultralow-resistance contacts to be discovered1,2. Atomically thin two-dimensional semiconductors have great potential for realizing high-performance electronic devices1,3. However, owing to metal-induced gap states (MIGS)4-7, energy barriers at the metal-semiconductor interface-which fundamentally lead to high contact resistance and poor current-delivery capability-have constrained the improvement of two-dimensional semiconductor transistors so far2,8,9. Here we report ohmic contact between semimetallic bismuth and semiconducting monolayer transition metal dichalcogenides (TMDs) where the MIGS are sufficiently suppressed and degenerate states in the TMD are spontaneously formed in contact with bismuth. Through this approach, we achieve zero Schottky barrier height, a contact resistance of 123 ohm micrometres and an on-state current density of 1,135 microamps per micrometre on monolayer MoS2; these two values are, to the best of our knowledge, the lowest and highest yet recorded, respectively. We also demonstrate that excellent ohmic contacts can be formed on various monolayer semiconductors, including MoS2, WS2 and WSe2. Our reported contact resistances are a substantial improvement for two-dimensional semiconductors, and approach the quantum limit. This technology unveils the potential of high-performance monolayer transistors that are on par with state-of-the-art three-dimensional semiconductors, enabling further device downscaling and extending Moore's law.

Boosting Monolayer Transition Metal Dichalcogenides Growth by Hydrogen-Free Ramping during Chemical Vapor Deposition.

The controlled vapor-phase synthesis of two-dimensional (2D) transition metal dichalcogenides (TMDs) is essential for functional applications. While chemical vapor deposition (CVD) techniques have been successful for transition metal sulfides, extending these methods to selenides and tellurides often faces challenges due to uncertain roles of hydrogen (H2) in their synthesis. Using CVD growth of MoSe2 as an example, this study illustrates the role of a H2-free environment during temperature ramping in suppressing the reduction of MoO3, which promotes effective vaporization and selenization of the Mo precursor to form MoSe2 monolayers with excellent crystal quality. As-synthesized MoSe2 monolayer-based field-effect transistors show excellent carrier mobility of up to 20.9 cm2/(V·s) with an on-off ratio of 7 × 107. This approach can be extended to other TMDs, such as WSe2, MoTe2, and MoSe2/WSe2 in-plane heterostructures. Our work provides a rational and facile approach to reproducibly synthesize high-quality TMD monolayers, facilitating their translation from laboratory to manufacturing.

Randomized Trial of Prophylactic Antibiotics for Endoscopic Retrograde Cholangiopancreatography in Patients With Biliary Obstruction.

INTRODUCTION: The incidence of postendoscopic retrograde cholangiopancreatography (ERCP) infections is reported to be up to 18% in patients with biliary obstruction. Antibiotic prophylaxis may reduce the risk of infectious complications after ERCP; however, the clinical value of prophylactic antibiotics in ERCP remains controversial. METHODS: We conducted a double-blind, placebo-controlled, randomized trial to investigate whether the use of prophylactic antibiotics would reduce infectious complications after ERCP in patients with biliary obstruction. We randomly assigned patients in a 1:1 ratio to receive either a single dose of 1 g intravenous cefoxitin or normal saline as a placebo 30 minutes before undergoing ERCP. The primary outcome was the incidence of infectious complications after ERCP. RESULTS: We enrolled 378 patients, and 189 patients were assigned to each group. The risk of infectious complications after ERCP was 2.8% (5 of 176 patients) in the antibiotic prophylaxis group and 9.8% (17 of 173 patients) in the placebo group (risk ratio, 0.29; 95% confidence interval [CI], 0.11-0.74, P = 0.0073). The incidence rates of bacteremia were 2.3% (4 of 176 patients) and 6.4% (11 of 173 patients), respectively (risk ratio, 0.36; 95% CI, 0.12-1.04; P = 0.0599). The incidence rate of cholangitis was 1.7% (3 of 176 patients) in the antibiotic prophylaxis group and 6.4% (11 of 173 patients) in the placebo group (risk ratio, 0.27; 95% CI, 0.08-0.87; P = 0.0267). DISCUSSION: Antibiotic prophylaxis before ERCP in patients with biliary obstruction resulted in a significantly lower risk of infectious complications, especially cholangitis, than placebo ( ClinicalTrials.gov trial number NCT02958059).

Clinical impact of pancreatic steatosis measured by CT on the risk of post-ERCP pancreatitis: a multicenter prospective trial.

BACKGROUND AND AIMS: Pancreatic steatosis (PS) may be a risk factor for acute pancreatitis. Whether it is also a risk factor for post-ERCP pancreatitis (PEP) has not been evaluated. This study aimed to determine the impact of PS on PEP development. METHODS: This multicenter prospective trial enrolled 786 consecutive patients who underwent contrast-enhanced abdominal CT and subsequent first-time ERCP. PS was evaluated based on pancreatic attenuation on unenhanced CT images. The risk of PS for the development of PEP was evaluated using a logistic regression model. RESULTS: Of 527 patients included in the study, 157 (29.8%) had PS and 370 (70.2%) did not. At 24 hours after ERCP, there was a significant difference in the PEP identified in 22 patients (14.0%) in the PS group and 23 patients (6.2%) in the "no PS" (NPS) group (P = .017). Diabetes and hypertension were more common in the PS group than in the NPS group; no differences in dyslipidemia were found. Patients with PS had a higher risk for the development of PEP than those with NPS (odds ratio, 2.09; 95% confidence interval, 1.08-4.03). No other variables were identified as risk factors for PEP. CONCLUSIONS: PS is a significant risk factor for PEP for which preventive measures should be considered. Standardized measurement protocols to assess PS by CT are needed. (Clinical trial registration number: KCT0006068.).

Risk of hematologic malignant neoplasms from head CT radiation in children and adolescents presenting with minor head trauma: a nationwide population-based cohort study.

OBJECTIVES: The carcinogenic risks of CT radiation in children and adolescents remain debated. We aimed to assess the carcinogenic risk of CTs performed in children and adolescents with minor head trauma. METHODS: In this nationwide population-based cohort study, we included 2,411,715 patients of age 0-19 with minor head trauma from 2009 to 2017. We excluded patients with elevated cancer risks or substantial past medical radiation exposure. Patients were categorized into CT-exposed or CT-unexposed group according to claim codes for head CT. The primary outcome was development of hematologic malignant neoplasms. Secondary outcomes included development of malignant solid neoplasms and benign neoplasms in the brain. We measured the incidence rate ratio (IRR) and incidence rate difference (IRD) using G-computation with Poisson regression adjusting for age, sex, hospital setting, and the type of head trauma. RESULTS: Hematologic malignant neoplasms developed in 100 of 216,826 patients during 1,303,680 person-years in the CT-exposed group and in 808 of 2,194,889 patients during 13,501,227 person-years in the CT-unexposed group. For hematologic malignant neoplasms, the IRR was 1.29 (95% CI, 1.03-1.60) and the IRD was 1.71 (95% CI, 0.04-3.37) per 100,000 person-years at risk. The majority of excess hematologic malignant neoplasms were leukemia (IRR, 1.40 [98.3% CI, 1.05-1.87]; IRD, 1.59 [98.3% CI, 0.02-3.16] per 100,000 person-years at risk). There were no between-group differences for secondary outcomes. CONCLUSIONS: Radiation exposure from head CTs in children and adolescents with minor head trauma was associated with an increased incidence of hematologic malignant neoplasms. CLINICAL RELEVANCE STATEMENT: Our study provides a quantitative grasp of the risk conferred by CT examinations in children and adolescents, thereby providing the basis for cost-benefit analyses and evidence-driven guidelines for patient triaging in head trauma. KEY POINTS: • This nationwide population-based cohort study showed that radiation exposure from head CTs in children and adolescents was associated with a higher incidence of hematologic malignant neoplasms. • The incidence rate of hematologic malignant neoplasms in the CT-exposed group was 29% higher than that in the CT-unexposed group (IRR, 1.29 [95% CI, 1.03-1.60]), and there were approximately 1.7 excess neoplasms per 100,000 person-years at risk in the CT-exposed group (IRD, 1.71 [0.04-3.37]). • Our study provides a quantified grasp of the risk conferred by CT examinations in children and adolescents, while controlling for biases observed in previous studies via specifying CT indication and excluding patients with predisposing conditions for cancer development.

Sex-dependent different clinicopathological characterization of Epstein-Barr virus-associated gastric carcinoma: a large-scale study.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) has been reported to account for approximately 5-16% of all GCs with good prognosis compared to EBV-negative GC. We evaluated the clinicopathological characteristics of EBVaGC including survival rate in South Korea. METHODS: A total of 4,587 patients with GC who underwent EBV in situ hybridization (EBV-ISH) were prospectively enrolled at the Seoul National University Bundang Hospital from 2003 to 2021. Age, sex, smoking status, cancer type and stage, tumor size and location, histological type, molecular features and survival information were analyzed. RESULTS: A total of 456 patients with GC (9.9%) were positive for EBV. The EBVaGC group displayed a higher proportion of males (P < 0.001), a predominant presence in the proximal stomach (P < 0.001), a higher proportion of undifferentiated cancer (P < 0.001), and a lower cancer stage (P = 0.004) than the EBV-negative group. Cox multivariate analyses revealed age (hazard ratio [HR] = 1.025, P < 0.001), tumor size (HR = 1.109, P < 0.001), and cancer stage (stage2 HR = 4.761, P < 0.001; stage3 HR = 13.286, P < 0.001; stage4 HR = 42.528, P < 0.001) as significant risk factors for GC-specific mortality, whereas EBV positivity was inversely correlated (HR = 0.620, P = 0.022). Furthermore, the EBVaGC group displayed statistically significant survival advantages over the EBV-negative cancer group in terms of both overall (P = 0.021) and GC-specific survival (P = 0.007) on the Kaplan-Meier survival curve. However, this effect was evident only in males. CONCLUSIONS: EBVaGC patients showed better prognoses despite their association with proximal location and poorly differentiated histology in male, probably due to the difference in immunity between males and females.

Optimal Insertion Depth of Central Venous Catheter through the Right Internal Jugular Vein, Verified by Transesophageal Echocardiography: A Prospective Observational Study.

This prospective observational study investigated the optimal insertion depth of the central venous catheter through the right internal jugular vein using transesophageal echocardiography. After tracheal intubation, the anesthesiologist inserted a probe for esophageal echocardiography into the patient's esophagus. The investigators placed the catheter tip 2 cm above the superior edge of the crista terminalis with echocardiography, which was defined as the optimal point. We measured the inserted length of the catheter. Pearson correlation tests were performed with the measured optimal depth and some patient parameters. We made a new formula for placing the catheter at the optimal position. A total of 89 subjects were enrolled in this trial. The correlation coefficient between the measured optimal depth and the patient's parameters was the highest for patient height (0.703, p < 0.001). We made a new formula of 'height (cm)/10 - 1.5 cm'. The accuracy rate of this formula for the optimal zone was 71.9% (95% confidence interval; 62.4 - 81.4%), which was the highest among the previous formulas or guidelines when we compared. In conclusion, the central venous catheter tip was evaluated with transesophageal echocardiography, and we could make a new formula of 'height (cm)/10 - 1.5', which seemed to be better than other previous guidelines.

Designing artificial two-dimensional landscapes via atomic-layer substitution.

Technology advancements in history have often been propelled by material innovations. In recent years, two-dimensional (2D) materials have attracted substantial interest as an ideal platform to construct atomic-level material architectures. In this work, we design a reaction pathway steered in a very different energy landscape, in contrast to typical thermal chemical vapor deposition method in high temperature, to enable room-temperature atomic-layer substitution (RT-ALS). First-principle calculations elucidate how the RT-ALS process is overall exothermic in energy and only has a small reaction barrier, facilitating the reaction to occur at room temperature. As a result, a variety of Janus monolayer transition metal dichalcogenides with vertical dipole could be universally realized. In particular, the RT-ALS strategy can be combined with lithography and flip-transfer to enable programmable in-plane multiheterostructures with different out-of-plane crystal symmetry and electric polarization. Various characterizations have confirmed the fidelity of the precise single atomic layer conversion. Our approach for designing an artificial 2D landscape at selective locations of a single layer of atoms can lead to unique electronic, photonic, and mechanical properties previously not found in nature. This opens a new paradigm for future material design, enabling structures and properties for unexplored territories.

Effect of Twist Angle on Interfacial Thermal Transport in Two-Dimensional Bilayers.

Advances in two-dimensional (2D) devices require innovative approaches for manipulating transport properties. Analogous to the electrical and optical responses, it has been predicted that thermal transport across 2D materials can have a similar strong twist-angle dependence. Here, we report experimental evidence deviating from this understanding. In contrast to the large tunability in electrical transport, we measured an unexpected weak twist-angle dependence of interfacial thermal transport in MoS2 bilayers, which is consistent with theoretical calculations. More notably, we confirmed the existence of distinct regimes with weak and strong twist-angle dependencies for thermal transport, where, for example, a much stronger change with twist angles is expected for graphene bilayers. With atomic simulations, the distinct twist-angle effects on different 2D materials are explained by the suppression of long-wavelength phonons via the moiré superlattice. These findings elucidate the unique feature of 2D thermal transport and enable a new design space for engineering thermal devices.

Two-Terminal MoS2 Memristor and the Homogeneous Integration with a MoS2 Transistor for Neural Networks.

Memristors are promising candidates for constructing neural networks. However, their dissimilar working mechanism to that of the addressing transistors can result in a scaling mismatch, which may hinder efficient integration. Here, we demonstrate two-terminal MoS2 memristors that work with a charge-based mechanism similar to that in transistors, which enables the homogeneous integration with MoS2 transistors to realize one-transistor-one-memristor addressable cells for assembling programmable networks. The homogenously integrated cells are implemented in a 2 × 2 network array to demonstrate the enabled addressability and programmability. The potential for assembling a scalable network is evaluated in a simulated neural network using obtained realistic device parameters, which achieves over 91% pattern recognition accuracy. This study also reveals a generic mechanism and strategy that can be applied to other semiconducting devices for the engineering and homogeneous integration of memristive systems.

Revealing Variable Dependences in Hexagonal Boron Nitride Synthesis via Machine Learning.

Wafer-scale monolayer two-dimensional (2D) materials have been realized by epitaxial chemical vapor deposition (CVD) in recent years. To scale up the synthesis of 2D materials, a systematic analysis of how the growth dynamics depend on the growth parameters is essential to unravel its mechanisms. However, the studies of CVD-grown 2D materials mostly adopted the control variate method and considered each parameter as an independent variable, which is not comprehensive for 2D materials growth optimization. Herein, we synthesized a representative 2D material, monolayer hexagonal boron nitride (hBN), on single-crystalline Cu (111) by epitaxial chemical vapor deposition and varied the growth parameters to regulate the hBN domain sizes. Furthermore, we explored the correlation between two growth parameters and provided the growth windows for large flake sizes by the Gaussian process. This new analysis approach based on machine learning provides a more comprehensive understanding of the growth mechanism for 2D materials.

Pulsed radiofrequency of lumbar dorsal root ganglion for lumbar radicular pain: A systematic review and meta-analysis.

BACKGROUND: Pulsed radiofrequency (PRF) of the lumbar dorsal root ganglion (DRG) has been widely used as a method to relieve lumbar radicular pain (LRP). However, the value of PRF application in LRP patients remains uncertain. This systematic review aimed to compare the effects of PRF of lumbar DRG and LEI in patients with LRP. METHODS: A literature search was performed using well-known databases for articles published up to May 2023. We included randomized controlled trials (RCTs) that evaluated the effects of PRF compared to LEI with or without steroids. We screened articles, extracted data, and assessed risk of bias in duplicate. The pain scores and Oswestry Disability Index (ODI) scores at 1, 3, and 6 months after procedures were obtained. A random-effects meta-analysis model was applied for outcomes. We evaluated evidence certainty for each outcome using the GRADE scoring system. This review was registered in the PROSPERO (ID: CRD42021253628). RESULTS: A total of 10 RCTs were included and data of 613 patients were retrieved. We assessed the overall quality of the evidence as very low to moderate. PRF showed no difference in pain scores at 1 (mean difference [MD] -0.80, 95% confidence interval [CI] -1.59 to 0.00, low certainty) and 6 months (MD -2.37, 95% CI -4.79 to 0.05, very low certainty), and significantly improved pain scores at 3 months (MD -1.31, 95% CI -2.29 to -0.33, low certainty). There was no significant difference in ODI score at any interval (very low to low certainty). In the subgroup who underwent a diagnostic block, did not use steroids, and PRF duration greater than 360 s, PRF significantly reduced pain scores at 3 months after procedures. CONCLUSIONS: We found low quality of the evidence supporting adjuvant PRF to the lumbar DRG has a greater analgesic effect at 3 months after procedures in patients with LRP than LEI. We identified no convincing evidence to show that this treatment improves function. High-quality evidence is lacking, and data were largely derived from short-term effects. Given these limitations, high-quality trials with data on long-term effects are needed.

Tuning colour centres at a twisted hexagonal boron nitride interface.

The colour centre platform holds promise for quantum technologies, and hexagonal boron nitride has attracted attention due to the high brightness and stability, optically addressable spin states and wide wavelength coverage discovered in its emitters. However, its application is hindered by the typically random defect distribution and complex mesoscopic environment. Here, employing cathodoluminescence, we demonstrate on-demand activation and control of colour centre emission at the twisted interface of two hexagonal boron nitride flakes. Further, we show that colour centre emission brightness can be enhanced by two orders of magnitude by tuning the twist angle. Additionally, by applying an external voltage, nearly 100% brightness modulation is achieved. Our ab initio GW and GW plus Bethe-Salpeter equation calculations suggest that the emission is correlated to nitrogen vacancies and that a twist-induced moiré potential facilitates electron-hole recombination. This mechanism is further exploited to draw nanoscale colour centre patterns using electron beams.

Staging Chest CT in Patients With Early-Stage Colon Cancer: Analysis of Impact on Survival Using Inverse Probability Weighting and Causal Diagram.

BACKGROUND. Staging chest CT has been shown to have negligible diagnostic yield for detecting lung metastases in patients with early-stage colon cancer. Nonetheless, staging chest CT may have potential survival benefits, including opportunistic screening of comorbidity and provision of a baseline examination for future comparisons. Evidence is lacking regarding the impact of staging chest CT on survival in patients with early-stage colon cancer. OBJECTIVE. The purpose of this study was to determine whether the performance of staging chest CT affects survival in patients with early-stage colon cancer. METHODS. This retrospective study included patients with early-stage colon cancer (defined as clinical stage 0 or I on staging abdominal CT) at a single tertiary hospital between January 2009 and December 2015. Patients were divided into two groups according to the presence of a staging chest CT examination. To ensure comparability between the two groups, inverse probability weighting was applied to adjust for the confounders derived from a causal diagram. The between-group differences in adjusted restricted mean survival time at 5 years were measured for overall survival, relapse-free survival, and thoracic metastasis-free survival. Sensitivity analyses were performed. RESULTS. A total of 991 patients (618 men and 373 women; median age, 64 years [IQR, 55-71 years]) were included: 606 patients (61.2%) had staging chest CT. For overall survival, the difference between groups in restricted mean survival time at 5 years was not significant (0.4 months [95% CI, -0.8 to 2.1 months]). The differences between groups in restricted mean survival at 5 years were also not significant for relapse-free survival (0.4 months [95% CI, -1.1 to 2.3 months]) and for thoracic metastasis-free survival (0.6 months [95% CI, -0.8 to 2.4 months]). Similar results were observed in sensitivity analyses that tested 3- and 10-year RMST differences, excluded patients who underwent FDG PET/CT during staging workup, and added treatment decision (surgery vs no surgery) to the causal diagram. CONCLUSION. The use of staging chest CT did not affect survival in patients with early-stage colon cancer. CLINICAL IMPACT. Staging chest CT may be omitted from the staging workup for patients with colon cancer of clinical stage 0 or I.

Electrical Control of Chemical Vapor Deposition of Graphene.

Chemical vapor deposition (CVD) is widely used for the efficient growth of low-dimensional materials. The growth mechanism comprises mass and heat transport, gas-phase and surface chemical reactions, and the interaction between the product and the substrate/catalyst. Correspondingly, the controllable parameter space is conventionally focused on the mass flow of each component, the temperature of the reaction chamber and the substrate, and the material and structure of the substrate/catalyst. Here, we report that applying an electric field between the copper substrate and a counter electrode has significant impacts on the growth of graphene. Electrochemical effect and ionic collision effect are observed in different conditions. With the assistance of negative and positive voltages applied on the growth substrate, selective growth and rapid growth of clean graphene films are achieved, respectively. We anticipate such electrical control will open up new ways to assist the synthesis of two-dimensional (2D) materials.

Adrenal Nodules Detected at Staging CT in Patients with Resectable Gastric Cancers Have a Low Incidence of Malignancy.

Background Guidelines recommending additional imaging for adrenal nodules lack relevant epidemiologic evidence. Purpose To measure the prevalence of adrenal nodules detected at staging CT in patients with potentially resectable gastric cancer and the proportion of patients with malignant nodules among them. Materials and Methods This retrospective study included 10 250 consecutive patients (median age, 63 years; interquartile range, 53-71 years; 6884 men) who underwent staging CT and had potentially resectable gastric cancer in a tertiary center (May 2003 to December 2018). All 10 250 CT studies were retrospectively reviewed, and patients with adrenal nodules (or thickening ≥10 mm) were identified to measure the prevalence of adrenal nodules. Among patients with adrenal nodules, the per-patient proportions of malignant nodules, adrenal metastasis from gastric cancer, and additional adrenal examinations were measured. A secondary analysis was performed by using data from the original CT reports. The same metrics that were used in the retrospective review were assessed. Results The prevalence of adrenal nodules was 4.5% (95% CI: 4.1, 4.9; 462 of 10 250). The proportions of malignant nodules and adrenal metastasis from gastric cancer were 0.4% ( 95% CI: 0.1, 1.6; two of 462) and 0% (95% CI: 0.0, 0.8; 0 of 462), respectively. A total of 27% of the patients (95% CI: 23, 31; 123 of 462) underwent additional adrenal examination. According to original CT reports, the prevalence of adrenal nodules and the proportions of malignant nodules, adrenal metastases from gastric cancer, and additional adrenal examination were 2.7% (95% CI: 2.4, 3.0; 272 of 10 250), 0.7% (95% CI: 0.1, 2.6; two of 272), 0% (95% CI: 0.0, 1.4; 0 of 272), and 42.6% (95% CI: 36.7, 48.8; 116 of 272), respectively. Conclusion Although adrenal nodules were detected frequently on staging CT images of patients with otherwise resectable gastric cancer, these nodules were rarely malignant. ©RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Baumgarten in this issue.

Preoperative magnetic resonance imaging-based prognostic model for mass-forming intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: As most staging systems for intrahepatic cholangiocarcinoma (iCCA) are based on pathological results, preoperative prognostic prediction is limited. This study aimed to develop and validate a prognostic model for the overall survival of patients with mass-forming iCCA (MF-iCCA) using preoperative magnetic resonance imaging (MRI) and clinical findings. METHODS: We enrolled a total of 316 patients who underwent preoperative MRI and surgical resection for treatment-naive MF-iCCA from six institutions, between January 2009 and December 2015. The subjects were randomly assigned to a training set (n = 208) or validation set (n = 108). The MRIs were independently reviewed by three abdominal radiologists. Using MRI and clinical findings, an MRI prognostic score was established. We compared the discrimination performance of MRI prognostic scores with those of conventional pathological staging systems. RESULTS: We developed an MRI prognostic score consisting of serum CA19-9 and three MRI findings (tumour multiplicity, lymph node metastasis and bile duct invasion). The MRI prognostic score demonstrated good discrimination performance in both the training set (C-index, 0.738; 95% confidence interval [CI], 0.698-0.780) and validation set (C-index, 0.605; 95% CI, 0.526-0.680). In the validation set, MRI prognostic score showed no significant difference with AJCC 8th TNM stage, MEGNA score and Nathan's stage. CONCLUSIONS: Our MRI prognostic score for overall survival of MF-iCCA showed comparable discriminatory performance with pathological staging systems and might be used to determine an optimal treatment strategy.

Incidence of malignancy in adrenal nodules detected on staging CTs of patients with potentially resectable colorectal cancer.

OBJECTIVE: To measure the prevalence of adrenal nodules detected on staging CT in patients with resectable colorectal cancer, and the proportion of patients with malignant nodules among them. METHODS: This retrospective study included 6474 patients (median age, 65; interquartile range, 56-73; 3902 men) who underwent staging CT for colorectal cancer between May 2003 and December 2018. The patients had potentially resectable colorectal cancer, including resectable hepatic or pulmonary metastases. Through retrospective CT image review, patients with adrenal nodules were identified for the prevalence of adrenal nodule. Among patients with adrenal nodules, per-patient proportions of malignant nodules, adrenal metastasis from colorectal cancer, and additional adrenal examinations (biopsy or imaging tests) were measured. A secondary analysis was performed using data from the official CT reports. RESULTS: The prevalence of adrenal nodules was 5.6% (363 of 6474; 95% CI: 5.1, 6.2). The proportions of malignant nodules and adrenal metastasis from colorectal cancer were 0.8% (3 of 363; 0.2, 2.4) and 0.3% (1 of 363; 0.0, 1.5), respectively. 6.1% (22 of 363; 3.8, 9.0) of the patients underwent additional adrenal examination. According to official CT reports, the prevalence of adrenal nodules and proportions of malignant nodules, adrenal metastasis from colorectal cancer, and additional adrenal examination were 1.9% (125 of 6474; 1.6, 2.3), 1.6% (2 of 125; 0.2, 5.7), 0% (0 of 125; 0.0, 2.9), and 10.4% (1 of 125; 5.7, 17.1), respectively. CONCLUSION: Adrenal nodules detected in staging CTs in patients with otherwise resectable colorectal cancers are rarely malignant. KEY POINTS: • Among 6474 patients who underwent staging CT and had potentially resectable colorectal cancer, 363 had adrenal nodules (≥ 10 mm) detected in retrospective CT image review. • Three out of the 363 patients with adrenal nodules detected on staging CT had malignant adrenal nodules, one of whom had metastasis from colorectal cancer.

Tumor resectability and response on CT following neoadjuvant therapy for pancreatic cancer: inter-observer agreement study.

OBJECTIVES: First, to measure inter-observer agreement regarding tumor resectability and response, and second, to measure diagnostic performance in predicting negative resection margin, on re-staging CTs of patients who received neoadjuvant therapy for pancreatic cancer. METHODS: This retrospective study included patients who received neoadjuvant therapy for borderline resectable pancreatic cancer from 2017 to 2020. Six readers independently evaluated initial staging and re-staging CT images. They categorized the resectability on re-staging CT based on the NCCN guideline, and evaluated tumor response to neoadjuvant therapy according to our proposed criteria on a 5-grade scale. For inter-observer agreement, Gwet's agreement coefficients were used. A crossed random effect model was used to pool the sensitivity and specificity of six readers in predicting negative resection margin. RESULTS: Seventy-seven patients with the median age of 66 (59-70) were included. The pooled agreement for tumor resectability was 0.64 (95% CI, 0.56-0.71) for differentiating the three categories, and 0.84 (0.77-0.91) for differentiating resectable or borderline resectable cancer vs. unresectable cancer. Agreement for tumor response grade was 0.89 (0.85-0.92). The pooled sensitivity and specificity for predicting negative resection margin were 48% (43-52%) and 61% (57-64%), respectively, when only "resectable" on re-staging CT was considered as index test positive. When either "resectable"' or "borderline resectable" was considered as positive, the pooled sensitivity and specificity were 91% (89-94%) and 5% (4-6%), respectively. CONCLUSION: CT can be used reliably with a high inter-observer agreement in selecting candidates for surgery after neoadjuvant therapy of pancreatic cancer. KEY POINTS: • On CT following neoadjuvant therapy of pancreatic cancer, six readers showed high agreement in differentiating resectable or borderline resectable vs. unresectable cancer (Gwet's coefficient, 0.84). • Inter-observer agreement was also high for our proposed tumor response grade (Gwet's coefficient, 0.89). • Specificity was very low (5%) while sensitivity was high (91%) when either resectable or borderline resectable cancer on re-staging CT was considered as predictive of negative resection margin status.