Plug-assisted Retrograde Transvenous Obliteration-II for Gastric Varices: A Case Report

We present a case of gastric varices successfully treated with modified plug-assisted retrograde transvenous obliteration. A 45-year-old male patient had isolated fundal gastric varices caused by alcoholic cirrhosis. Contrast-enhanced computed tomography showed that the gastric varices were drained mainly via the gastro-renal shunt. The gastric varices were treated via plug-assisted retrograde transvenous obliteration using an IMPEDE vascular plug with a modified coil-assisted retrograde transvenous obliteration-II procedure. There were no complications during the procedure, and an endoscopic examination 3 months after the procedure revealed that the gastric varices had disappeared. To our knowledge, this is the first report on the application of plug-assisted retrograde transvenous obliteration-II using a newly designed IMPEDE vascular plug to avoid migration of the sclerosant.

Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Rapid Whole-Body FDG PET/MRI in Oncology Patients: Utility of Combining Bayesian Penalised Likelihood PET Reconstruction and Abbreviated MRI

This study evaluated the diagnostic value of a rapid whole-body fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) approach, combining Bayesian penalised likelihood (BPL) PET with an optimised β value and abbreviated MRI (abb-MRI). The study compares the diagnostic performance of this approach with the standard PET/MRI that utilises ordered subsets expectation maximisation (OSEM) PET and standard MRI (std-MRI). The optimal β value was determined by evaluating the noise-equivalent count (NEC) phantom, background variability, contrast recovery, recovery coefficient, and visual scores (VS) for OSEM and BPL with β100-1000 at 2.5-, 1.5-, and 1.0-min scans, respectively. Clinical evaluations were conducted for NEC_patient, NEC_density, liver signal-to-noise ratio (SNR), lesion maximum standardised uptake value, lesion signal-to-background ratio, lesion SNR, and VS in 49 patients. The diagnostic performance of BPL/abb-MRI was retrospectively assessed for lesion detection and differentiation in 156 patients using VS. The optimal β values were β600 for a 1.5-min scan and β700 for a 1.0-min scan. BPL/abb-MRI at these β values was equivalent to OSEM/std-MRI for a 2.5-min scan. By combining BPL with optimal β and abb-MRI, rapid whole-body PET/MRI could be achieved in ≤1.5 min per bed position, while maintaining comparable diagnostic performance to standard PET/MRI.

[18F]FES PET Resolves the Diagnostic Dilemma of COVID-19-Vaccine-Associated Hypermetabolic Lymphadenopathy in ER-Positive Breast Cancer

Coronavirus disease (COVID-19) vaccination is known to cause a diagnostic dilemma due to false-positive findings on [¹⁸F]FDG PET in vaccine-associated hypermetabolic lymphadenopathy. We present two case reports of women with estrogen-receptor (ER)-positive cancer of the breast who were vaccinated for COVID-19 in the deltoid muscle. [¹⁸F]FDG positron emission tomography (PET) demonstrated primary breast cancer and multiple axillary lymph nodes with increased [¹⁸F]FDG uptake, diagnosed as vaccine-associated [¹⁸F]FDG-avid lymph nodes. Subsequent [¹⁸F]FES PET revealed single axillary lymph node metastasis in the vaccine-associated [¹⁸F]FDG-avid lymph nodes. To the best of our knowledge, this is the first study showing the usefulness of [¹⁸F]FES PET in diagnosing axillary lymph node metastasis in COVID-19-vaccinated patients harboring ER-positive breast cancer. Thus, [¹⁸F]FES PET has potential applications in the detection of true-positive metastatic lymph nodes in patients with ER-positive breast cancer regardless of the ipsilateral or contralateral side, who have received COVID-19 vaccination.

Improved diagnosis of histological capsule in hepatocallular carcinoma by using nonenhancing capsule appearance in addition to enhancing capsule appearance in gadoxetic acid-enhanced MRI

To assess the value of nonenhancing capsule by adding to enhancing capsule in gadoxetic acid-enhanced MRI (EOB-MRI) in comparison with contrast-enhanced CT (CE-CT) for diagnosing histological capsule in hepatocellular carcinoma (HCC). One-hundred fifty-one patients with HCC who underwent both CE-CT and EOB-MRI were retrospectively reviewed. Liver Imaging-Reporting and Data System (LI-RADS) v2018 imaging features, including enhancing and nonenhancing capsule were evaluated by two readers in CE-CT and EOB-MRI. Frequencies of each imaging feature were compared between CE-CT and EOB-MRI. The area under the receiver operating characteristic (AUC) curve for the diagnosis of histological capsule was compared across the following three imaging criteria: (1) enhancing capsule in CE-CT, (2) enhancing capsule in EOB-MRI, and (3) enhancing/nonenhancing capsule in EOB-MRI. Enhancing capsule in EOB-MRI was significantly less frequently depicted than that in CE-CT (p < 0.001 and = 0.016 for reader 1 and 2). Enhancing/nonenhancing capsule in EOB-MRI achieved a similar frequency of enhancing in CE-CT (p = 0.590 and 0.465 for reader 1 and 2). Adding nonenhancing capsule to enhancing capsule in EOB-MRI significantly increased AUCs (p < 0.001 for both readers) and achieved similar AUCs compared with enhancing capsule in CE-CT (p = 0.470 and 0.666 for reader 1 and 2). Adding nonenhancing capsule to the definition of capsule appearance can improve the diagnosis of capsule in EOB-MRI for the diagnosis of histological capsule in HCC and decrease discordance of capsule appearance between EOB-MRI and CE-CT.

Clinical Practice Guidelines for Hepatocellular Carcinoma: The Japan Society of Hepatology 2021 version (5th JSH-HCC Guidelines)

The fifth version of the Clinical Practice Guidelines for Hepatocellular Carcinoma was revised by the Japan Society of Hepatology, according to the methodology of evidence-based medicine and partly to the Grading of Recommendations Assessment, Development and Evaluation system, which was published in October 2021 in Japanese. In addition to surveillance-diagnostic and treatment algorithms, a new algorithm for systemic therapy has been created, as multiple drugs for hepatocellular carcinoma can be currently selected. Here, new or revised algorithms and evidence on which the recommendations are based are described.

Evaluation and Prediction of Treatment Response for Hepatocellular Carcinoma

The incidence of hepatocellular carcinoma (HCC) is still on the rise in North America and Europe and is the second leading cause of cancer-related mortality. The treatment of HCC varies, with surgery and locoregional therapy (LRT) such as radiofrequency ablation and transcatheter arterial chemoembolization, and radiation therapy being the primary treatment. Currently, systemic therapy with molecular-targeted agents and immune checkpoint inhibitors (ICIs) is becoming a major treatment option for the unresectable HCC. As the HCC after LRT or systemic therapy often remains unchanged in size and shows loss of contrast effect in contrast-enhanced CT or MRI, the response evaluation criteria in solid tumors (RECIST) and World Health Organization criteria, which are usually used to evaluate the treatment response of solid tumors, are not appropriate for HCC. The modified RECIST (mRECIST) and the European Association for the Study of the Liver (EASL) criteria were developed for HCC, with a focus on viable lesions. The latest 2018 edition of the Liver Imaging Reporting and Data System (LI-RADS) also includes a section on the evaluation of treatment response. The cancer microenvironment influences the therapeutic efficacy of ICIs. Several studies have examined the utility of gadoxetic acid-enhanced MRI for predicting the pathological and molecular genetic patterns of HCC. In the future, it may be possible to stratify prognosis and predict treatment response prior to systemic therapy by using pre-treatment imaging findings.

Reevaluation of Makuuchi's criteria for resecting hepatocellular carcinoma: A Japanese nationwide survey

AIM

Although Makuuchi's criteria are widely used to determine the cut-off for safe liver resection, there have been few reports of concrete data supporting their validity. Here, we verified the utility of Makuuchi's criteria by comparing the operative mortality rates associated with liver resection between hepatocellular carcinoma (HCC) patients meeting or exceeding the criteria.

METHODS

A database was built using data from 15 597 patients treated between 2000 and 2007 for whom values for all three variables included in Makuuchi's criteria for liver resection (clinical ascites, serum bilirubin, and indocyanine green clearance) were available. The patients were divided into those fulfilling (n = 12 175) or exceeding (n = 3422) the criteria. The postoperative mortality (death for any reason within 30 days) and long-term survival were compared between the two groups.

RESULTS

The operative mortality rate was significantly lower in patients meeting the criteria than in those exceeding the criteria (1.07% vs. 2.01%, respectively; p < 0.001). On multivariate analysis, exceeded the criteria was significantly associated with the risk for operative mortality (relative risk 2.08; 95% confidence interval (CI), 1.23-3.52; p = 0.007). Surgical indication meeting or exceeding the criteria was an independent factor for overall survival (hazard ratio 1.27; 95% CI, 1.18-1.36; p < 0.001).

CONCLUSION

Makuuchi's criteria are suitable for determining the indication for resection of HCC due to the reduction in risk of operative mortality.

Real world data of systemic therapy for hepatocellular carcinoma in Japan: HERITAGE study

510

Background: Currently 6 regimens are available for advanced hepatocellular carcinoma (HCC) in Japan, including atezolizumab plus bevacizumab (AB), sorafenib (S), and lenvatinib (L) for first-line treatment and regorafenib (R), ramucirumab (RAM), and cabozantinib (C) for the second-line treatment. In real-world clinical practice, the number of combinations of treatment sequences is enormous. We have launched a nationwide registry of systemic therapy for HCC named Hepatoma Registry of Integrating and Aggregating Electric Health Records (HERITAGE). Methods: The HERITAGE is linked to the nationwide follow-up survey of the Japan Liver Cancer Association; cases treated with systemic therapy between 2015 and 2022 were included in the current study. Information on treatment efficacy and duration was collected and registered on each treatment regimen. Results: As of June 2022, 6,400 treatment lines (S 2,319, L 2559, AB 768, R 406, RAM 251, C 71) in 4,307 cases were enrolled. The response rates, disease control rates, and median treatment duration of each sequence of regimens are shown in the table. The 1st line regimen, S, L, and AB, were also used as the second and later lines in Japan and found as effective as if used as the 1st line treatment. Limitation: No adjustments for clinical conditions were performed. Conclusions: We have demonstrated the efficacy of various treatment sequences in a sufficient number of cases. Clinical trial information: UMIN000046567 . [Table: see text]

Bayesian multidimensional nominal response model for observer study of radiologists

PURPOSE

This study proposes a Bayesian multidimensional nominal response model (MD-NRM) to statistically analyze the nominal response of multiclass classifications.

MATERIALS AND METHODS

First, for MD-NRM, we extended the conventional nominal response model to achieve stable convergence of the Bayesian nominal response model and utilized multidimensional ability parameters. We then applied MD-NRM to a 3-class classification problem, where radiologists visually evaluated chest X-ray images and selected their diagnosis from one of the three classes. The classification problem consisted of 150 cases, and each of the six radiologists selected their diagnosis based on a visual evaluation of the images. Consequently, 900 (= 150 × 6) nominal responses were obtained. In MD-NRM, we assumed that the responses were determined by the softmax function, the ability of radiologists, and the difficulty of images. In addition, we assumed that the multidimensional ability of one radiologist were represented by a 3 × 3 matrix. The latent parameters of the MD-NRM (ability parameters of radiologists and difficulty parameters of images) were estimated from the 900 responses. To implement Bayesian MD-NRM and estimate the latent parameters, a probabilistic programming language (Stan, version 2.21.0) was used.

RESULTS

For all parameters, the Rhat values were less than 1.10. This indicates that the latent parameters of the MD-NRM converged successfully.

CONCLUSION

The results show that it is possible to estimate the latent parameters (ability and difficulty parameters) of the MD-NRM using Stan. Our code for the implementation of the MD-NRM is available as open source.

Comparison of Conventional Imaging and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnostic Accuracy of Staging in Patients with Intrahepatic Cholangiocarcinoma

We aimed to examine the accuracy of tumor staging of intrahepatic cholangiocarcinoma (ICC) by using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET-CT). From January 2001 to December 2021, 202 patients underwent PET-CT, CT, and MRI for the initial staging of ICC in two institutions. Among them, 102 patients had undergone surgical treatment. Ninety patients who had a histopathological diagnosis of ICC were retrospectively reviewed. The sensitivity and specificity of 18F-FDG PET-CT, CT, and magnetic resonance imaging (MRI) in detecting tumors, satellite focus, vascular invasion, and lymph node metastases were analyzed. Ninety patients with histologically diagnosed ICC were included. PET-CT demonstrated no statistically significant advantage over CT and MR in the diagnosis of multiple tumors and macrovascular invasion, and bile duct invasion. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET-CT in lymph node metastases were 84%, 86%, 91%, 84%, and 86%, respectively. PET-CT revealed a significantly higher accuracy compared to CT or MRI (86%, 67%, and 76%, p < 0.01, respectively) in the diagnosis of regional lymph node metastases. The accuracy of tumor staging by PET-CT was higher than that by CT/MRI (PET-CT vs. CT vs. MRI: 68/90 vs. 47/90 vs. 51/90, p < 0.05). 18F-FDG PET-CT had sensitivity and specificity values for diagnosing satellite focus and vascular and bile duct invasion similar to those of CT or MRI; however, PET-CT showed higher accuracy in diagnosing regional lymph node metastases. 18F-FDG PET-CT exhibited higher tumor staging accuracy than that of CT/MRI. Thus, 18FDG PET-CT may support tumor staging in ICC.

Influence of Metal Implants on Quantitative Evaluation of Bone Single-Photon Emission Computed Tomography/Computed Tomography

When visualizing biological activity at nonunion sites by the radioisotopes, gamma rays are more attenuated if metal implants are placed in the bone. However, the effects of various implant types and their placement on gamma ray attenuation in quantitative evaluation remain unknown. To elucidate these effects, we created a phantom that simulated the nonunion of the femur in this study. The count of gamma rays was measured by single-photon emission computed tomography/computed tomography (SPECT/CT) while considering CT-based attenuation correction (CTAC), metal implant placement, type (intramedullary nail or plate), and position. The count differed significantly with and without CTAC and with and without implants (both types) under CTAC. Significantly different counts were observed between the intramedullary nail and plate placed contralaterally to the lesion (i.e., non-lesion side). No significant difference was observed between the intramedullary nail and plate on the lesion side or between plates on the non-lesion and lesion sides. The measured standardized uptake value (SUV) was closer to the true SUV with CTAC than without. Moreover, the count was higher with implants than without. However, even with implants, it was lower than the actual count, indicating the absence of overcorrection. Implant type and position do not seem to influence the count.

Transcatheter arterial embolization for hemothorax caused by spinal fracture without arterial injury: a case report and review of the literature

Background

Spinal fractures rarely cause hemothorax, and no treatment consensus has been reached. Conservative treatment is generally selected in cases without arterial injury, but there have been some reports of uncontrolled bleeding. Here we report a case of hemothorax caused by spinal fracture without arterial injury treated with transcatheter arterial embolization.

Case presentation

An 88-year-old Japanese woman with back pain was diagnosed with hemothorax due to bleeding from an unstable fracture of the tenth thoracic vertebra. Contrast-enhanced computed tomography revealed no obvious arterial injury. We performed transcatheter arterial embolization of the bilateral tenth intercostal arteries to prevent rebleeding. The hemothorax did not worsen until surgical spinal fixation 9 days post-transcatheter arterial embolization, and she was discharged 30 days after admission.

Conclusion

Transcatheter arterial embolization for hemothorax caused by spinal fractures without obvious arterial injury may be a useful bridge to spinal fixation.

Abbreviated Gadoxetic Acid-Enhanced MRI for the Detection of Liver Metastases in Patients With Potentially Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) is useful in detecting liver metastases from pancreatic ductal adenocarcinoma (PDAC). However, the long examination time limits its utility in the initial workup of patients with PDAC.

PURPOSE

To evaluate the incremental value of an abbreviated gadoxetic acid-enhanced MRI for the detection of liver metastases in patients with PDAC.

STUDY TYPE

Retrospective.

POPULATION

Patients (N = 130) with potentially resectable PDAC (women, 58 [44.6%]).

FIELD STRENGTH/SEQUENCE

1.5 T and 3 T; gradient dual-echo T1-weighted (in-phase and opposed-phase), fat-suppressed fast spin-echo T2-weighted, single-shot echo-planar diffusion-weighted, and three-dimensional fat-suppressed T1-weighted gradient-echo dynamic contrast-enhanced and hepatobiliary phase sequences, as well as contrast-enhanced computed tomography (CECT).

ASSESSMENT

Three radiologists independently reviewed three different image sets to detect liver metastases: set 1, CECT alone; set 2, CECT and abbreviated MRI comprising fat-suppressed T2-weighted, diffusion-weighted, and hepatobiliary phase images; and set 3, CECT and standard gadoxetic acid-enhanced MRI.

STATISTICAL TESTS

Figure of merit (FOM) was compared using the jackknife alternative free-response receiver operating characteristics, and other per-lesion and per-patient diagnostic parameters for each image set were compared using McNemar's and Fisher's test. P < 0.05 was considered statistically significant.

RESULTS

A total of 43 liver metastases were identified in 13 patients. Reader-averaged FOM to detect liver metastases were significantly higher for sets 2 (0.884) and 3 (0.886) than for set 1 (0.609), while they were comparable between sets 2 and 3 (P = 0.96). The mean per-patient sensitivities, negative predictive values, and accuracies were significantly higher for sets 2 and 3 than for set 1, while those between sets 2 and 3 were not significantly different (not applicable, P > 0.99, and P > 0.99, respectively).

DATA CONCLUSION

Gadoxetic acid-enhanced MRI combined with CECT had higher diagnostic performance than CECT alone for the detection of liver metastases in patients with PDAC. The incremental values were comparable for the abbreviated MRI and standard MRI.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Transarterial Chemoebolization in Hepatocellular Carcinoma: A Binational Japanese-German Study

Objective

The purpose of this study was to investigate outcomes of transarterial chemoembolization (TACE) in treating hepatocellular carcinoma (HCC) comparing the different approaches used in Germany and Japan.

Methods

This binational IRB-approved retrospective dual-center study included a total of 94 HCC patients subdivided in a German and a Japanese cohort. For each patient, liver and tumor volumetry was performed using computed tomography (CT) and magnetic resonance imaging (MRI). Furthermore, a comprehensive risk profile, including body constitution and liver and kidney function was established. Primary endpoints were progression-free and overall survival (PFS/OS).

Results

PFS in the German cohort was 168 vs 224d in the Japanese cohort (p=0.640). When subdivided by BCLC stage, no significant differences were reported (p=0.160–0.429). OS was significantly longer in the Japanese cohort with 856 vs. 303d (p<0.001). OS for BCLC A was significantly longer in the Japanese cohort (1960 vs. 428d; p<0.001), while survival rates did not differ significantly in BCLC B (785 vs 330d; p=0.067) and C-stages (208 vs 302d; p=0.186). Older age (p=0.034), poorer liver/kidney function (p=0.025-0-035), and a higher liver/tumor ratio (p<0.001) were found to correlate with shorter survival. ECOG scores were significantly higher in the German cohort (p=0.002).

Conclusion

While OS is longer in TACE-treated patients in the Japanese cohort compared to the German cohort, the two approaches seem to be equally effective as PFS does not differ significantly. The different survival rates may be caused by the different clinical performance status of the selected collectives. In very early and early stage HCC, TACE in Japan seems to be an effective treatment option while in Germany for patients in those stages TACE remains a second-line option for patients not available for surgery or ablation.

FDG PET/MRI in Synchronous Uterine Adenocarcinoma and Leiomyosarcoma

ABSTRACT

A 52-year-old woman with a rapidly growing uterine tumor suspected of uterine sarcoma underwent 18F-FDG PET/MRI, revealing a myometrial mass and an endometrial lesion, suggesting dual primary neoplasms. Based on the PET/MRI findings, we changed the intraoperative procedure to determine the necessity of pelvic lymphadenectomy. PET/MRI was useful in diagnosing and differentiating between 2 malignant neoplasms in the uterus compared with PET/CT, due to MRI's high contrast resolution and precise fusion due to the simultaneous acquisition.

Response Evaluation Criteria in Cancer of the liver version 6 (Response Evaluation Criteria in Cancer of the Liver 2021 revised version)

Response Evaluation Criteria in Solid Tumors (RECIST) is inappropriate to assess the direct effects of treatment on hepatocellular carcinoma (HCC) by locoregional therapies, such as radiofrequency ablation or transarterial chemoembolization. Therefore, establishment of response evaluation criteria solely devoted to HCC is needed in clinical practice, as well as in clinical trials of HCC treatment, such as systemic therapies, which cause necrosis of the tumor. Response Evaluation Criteria in Cancer of the Liver (RECICL) was revised in 2021 by the Liver Cancer Study Group of Japan based on the 2019 version of RECICL, which was commonly used in Japan. The major revised points of the RECICL 2021 is inclusion of RECIST version 1.1 and modified RECIST as response evaluation criteria in systemic therapy for HCC. We hope this new treatment response criteria, RECICL, proposed by the Liver Cancer Study Group of Japan will benefit the HCC treatment response evaluation in the setting of daily clinical practice and clinical trials as well, not only in Japan, but also internationally.

Do the variations in ROI placement technique have influence for prostate ADC measurements?

Background

Prostate apparent diffusion coefficient (ADC) values calculated from diffusion-weighted imaging have been used for evaluating prostate cancer (PCa) aggressiveness. However, the way of measuring ADC values has varied depending on the study.

Purpose

To investigate inter- and intra-reader variability and diagnostic performance of three kinds of shaped 2D regions of interests (ROIs) for tumor ADC measurements in PCa.

Material and Methods

Seventy-four patients with PCa undergoing 3-T MRI before surgery were included. Histologic findings from radical prostatectomy specimens were reviewed to define each patient’s dominant tumor. Three readers independently measured the tumor ADCs using three different ROI methods: freehand, large-circle, and small-circles ROIs. Readers repeated measurements after 3 weeks. Bland-Altman analysis was performed to evaluate the inter- and intra-reader variability. Receiver Operating Characteristic analysis was used for assessment of tumor aggressiveness for PCa.

Results

For intra-reader and inter-reader variability, the mean coefficient of repeatability for freehand ROIs, large-circle ROIs, and small-circles ROIs were as follows: 13.7%, 12.4%, and 11.5%; 9.4%, 9.7%, and 9.5%. For differentiating Gleason score (GS) = 3 + 3 from GS ≥ 3 + 4 tumors, the area under the curves were 0.90 for freehand ROIs, 0.89 for large-circle ROIs, and 0.94 small-circles ROIs ( p = 0.31).

Conclusion

The variations in ROI method did not have a major influence on intra-reader or inter-reader reproducibility or diagnostic performance for prostate ADC measurements.

Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst)  eV and 6463.7±0.3(stat)±0.1(syst)  eV, and widths to be 2.5±1.0(stat)±0.4(syst)  eV and 1.0±0.6(stat)±0.3(stat)  eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

Comparison of prostate imaging reporting and data system v2.1 and 2 in transition and peripheral zones: evaluation of interreader agreement and diagnostic performance in detecting clinically significant prostate cancer

OBJECTIVE

To evaluate the interreader agreement and diagnostic performance of the Prostate Imaging Reporting and Data System (PI-RADS) v. 2.1, in comparison with v. 2.

METHODS

Institutional review board approval was obtained for this retrospective study. 77 consecutive patients who underwent a prostate multiparametric magnetic resonance imaging at 3.0 T before radical prostatectomy were included. Four radiologists (two experienced uroradiologists and two inexperienced radiologists) independently scored eight regions [six peripheral zones (PZ) and two transition zones (TZ)] using v. 2.1 and v. 2. Interreader agreement was assessed using κ statistics. To evaluate diagnostic performance for clinically significant prostate cancer (csPC), area under the curve (AUC) was estimated.

RESULTS

228 regions were pathologically diagnosed as positive for csPC. With a cut-off ≥3, the agreement among all readers was better with v. 2.1 than v. 2 in TZ, PZ, or both zones combined (κ-value: TZ, 0.509 vs 0.414; PZ, 0.686 vs 0.568; both zones combined, 0.644 vs 0.531). With a cut-off ≥4, the agreement among all readers was also better with v. 2.1 than v. 2 in the PZ or both zones combined (κ-value: PZ, 0.761 vs 0.701; both zones combined, 0.756 vs 0.709). For all readers, AUC with v. 2.1 was higher than with v. 2 (TZ, 0.826-0.907 vs 0.788-0.856; PZ, 0.857-0.919 vs 0.853-0.902).

CONCLUSION

Our study suggests that the PI-RADS v. 2.1 could improve the interreader agreement and might contribute to improved diagnostic performance compared with v. 2.

ADVANCES IN KNOWLEDGE

PI-RADS v. 2.1 has a potential to improve interreader variability and diagnostic performance among radiologists with different levels of expertise.

Diffusion and quantification of diffusion of prostate cancer

For assessing a cancer treatment, and for detecting and characterizing cancer, Diffusion-weighted imaging (DWI) is commonly used. The key in DWI's use extracranially has been due to the emergence of of high-gradient amplitude and multichannel coils, parallelimaging, and echo-planar imaging. The benefit has been fewer motion artefacts and high-quality prostate images.Recently, new techniques have been developed to improve the signal-to-noise ratio of DWI with fewer artefacts, allowing an increase in spatial resolution. For apparent diffusion coefficient quantification, non-Gaussian diffusion models have been proposed as additional tools for prostate cancer detection and evaluation of its aggressiveness. More recently, radiomics and machine learning for prostate magnetic resonance imaging have emerged as novel techniques for the non-invasive characterisation of prostate cancer. This review presents recent developments in prostate DWI and discusses its potential use in clinical practice.

Liver Cancer Study Group of Japan Clinical Practice Guidelines for Intrahepatic Cholangiocarcinoma

This paper presents the first version of clinical practice guidelines for intrahepatic cholangiocarcinoma (ICC) established by the Liver Cancer Study Group of Japan. These guidelines consist of 1 treatment algorithm, 5 background statements, 16 clinical questions, and 1 clinical topic, including etiology, staging, pathology, diagnosis, and treatments. Globally, a high incidence of ICC has been reported in East and Southeast Asian countries, and the incidence has been gradually increasing in Japan and also in Western countries. Reported risk factors for ICC include cirrhosis, hepatitis B/C, alcohol consumption, diabetes, obesity, smoking, nonalcoholic steatohepatitis, and liver fluke infestation, as well as biliary diseases, such as primary sclerosing cholangitis, hepatolithiasis, congenital cholangiectasis, and Caroli disease. Chemical risk factors include thorium-232, 1,2-dichloropropane, and dichloromethane. CA19-9 and CEA are recommended as tumor markers for early detection and diagnostic of ICC. Abdominal ultrasonography, CT, and MRI are effective imaging modalities for diagnosing ICC. If bile duct invasion is suspected, imaging modalities for examining the bile ducts may be useful. In unresectable cases, tumor biopsy should be considered when deemed necessary for the differential diagnosis and drug therapy selection. The mainstay of treatment for patients with Child-Pugh class A or B liver function is surgical resection and drug therapy. If the patient has no regional lymph node metastasis (LNM) and has a single tumor, resection is the treatment of choice. If both regional LNM and multiple tumors are present, drug therapy is the first treatment of choice. If the patient has either regional LNM or multiple tumors, resection or drug therapy is selected, depending on the extent of metastasis or the number of tumors. If distant metastasis is present, drug therapy is the treatment of choice. Percutaneous ablation therapy may be considered for patients who are ineligible for surgical resection or drug therapy due to decreased hepatic functional reserve or comorbidities. For unresectable ICC without extrahepatic metastasis, stereotactic radiotherapy (tumor size ≤5 cm) or particle radiotherapy (no size restriction) may be considered. ICC is generally not indicated for liver transplantation, and palliative care is recommended for patients with Child-Pugh class C liver function.