Comparative analysis of glymphatic system alterations in multiple sclerosis and neuromyelitis optica spectrum disorder using MRI indices from diffusion tensor imaging

OBJECTIVE

The glymphatic system is a glial-based perivascular network that promotes brain metabolic waste clearance. Glymphatic system dysfunction has been observed in both multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), indicating the role of neuroinflammation in the glymphatic system. However, little is known about how the two diseases differently affect the human glymphatic system. The present study aims to evaluate the diffusion MRI-based measures of the glymphatic system by contrasting MS and NMOSD.

METHODS

This prospective study included 63 patients with NMOSD (n = 21) and MS (n = 42) who underwent DTI. The fractional volume of extracellular-free water (FW) and an index of diffusion tensor imaging (DTI) along the perivascular space (DTI-ALPS) were used as indirect indicators of water diffusivity in the interstitial extracellular and perivenous spaces of white matter, respectively. Age and EDSS scores were adjusted.

RESULTS

Using Bayesian hypothesis testing, we show that the present data substantially favor the null model of no differences between MS and NMOSD for the diffusion MRI-based measures of the glymphatic system. The inclusion Bayes factor (BF10) of model-averaged probabilities of the group (MS, NMOSD) was 0.280 for FW and 0.236 for the ALPS index.

CONCLUSION

Together, these findings suggest that glymphatic alteration associated with MS and NMOSD might be similar and common as an eventual result, albeit the disease etiologies differ.

PRACTITIONER POINTS

Previous literature indicates important glymphatic system alteration in MS and NMOSD. We explore the difference between MS and NMOSD using diffusion MRI-based measures of the glymphatic system. We show support for the null hypothesis of no difference between MS and NMOSD. This suggests that glymphatic alteration associated with MS and NMOSD might be similar and common etiology.

Predicting hematoma expansion in acute spontaneous intracerebral hemorrhage: integrating clinical factors with a multitask deep learning model for non-contrast head CT

PURPOSE

To predict hematoma growth in intracerebral hemorrhage patients by combining clinical findings with non-contrast CT imaging features analyzed through deep learning.

METHODS

Three models were developed to predict hematoma expansion (HE) in 572 patients. We utilized multi-task learning for both hematoma segmentation and prediction of expansion: the Image-to-HE model processed hematoma slices, extracting features and computing a normalized DL score for HE prediction. The Clinical-to-HE model utilized multivariate logistic regression on clinical variables. The Integrated-to-HE model combined image-derived and clinical data. Significant clinical variables were selected using forward selection in logistic regression. The two models incorporating clinical variables were statistically validated.

RESULTS

For hematoma detection, the diagnostic performance of the developed multi-task model was excellent (AUC, 0.99). For expansion prediction, three models were evaluated for predicting HE. The Image-to-HE model achieved an accuracy of 67.3%, sensitivity of 81.0%, specificity of 64.0%, and an AUC of 0.76. The Clinical-to-HE model registered an accuracy of 74.8%, sensitivity of 81.0%, specificity of 73.3%, and an AUC of 0.81. The Integrated-to-HE model, merging both image and clinical data, excelled with an accuracy of 81.3%, sensitivity of 76.2%, specificity of 82.6%, and an AUC of 0.83. The Integrated-to-HE model, aligning closest to the diagonal line and indicating the highest level of calibration, showcases superior performance in predicting HE outcomes among the three models.

CONCLUSION

The integration of clinical findings with non-contrast CT imaging features analyzed through deep learning showed the potential for improving the prediction of HE in acute spontaneous intracerebral hemorrhage patients.

Added prognostic value of 3D deep learning-derived features from preoperative MRI for adult-type diffuse gliomas

BACKGROUND

To investigate the prognostic value of spatial features from whole-brain MRI using a three-dimensional (3D) convolutional neural network for adult-type diffuse gliomas.

METHODS

In a retrospective, multicenter study, 1925 diffuse glioma patients were enrolled from 5 datasets: SNUH (n = 708), UPenn (n = 425), UCSF (n = 500), TCGA (n = 160), and Severance (n = 132). The SNUH and Severance datasets served as external test sets. Precontrast and postcontrast 3D T1-weighted, T2-weighted, and T2-FLAIR images were processed as multichannel 3D images. A 3D-adapted SE-ResNeXt model was trained to predict overall survival. The prognostic value of the deep learning-based prognostic index (DPI), a spatial feature-derived quantitative score, and established prognostic markers were evaluated using Cox regression. Model evaluation was performed using the concordance index (C-index) and Brier score.

RESULTS

The MRI-only median DPI survival prediction model achieved C-indices of 0.709 and 0.677 (BS = 0.142 and 0.215) and survival differences (P < 0.001 and P = 0.002; log-rank test) for the SNUH and Severance datasets, respectively. Multivariate Cox analysis revealed DPI as a significant prognostic factor, independent of clinical and molecular genetic variables: hazard ratio = 0.032 and 0.036 (P < 0.001 and P = 0.004) for the SNUH and Severance datasets, respectively. Multimodal prediction models achieved higher C-indices than models using only clinical and molecular genetic variables: 0.783 vs. 0.774, P = 0.001, SNUH; 0.766 vs. 0.748, P = 0.023, Severance.

CONCLUSIONS

The global morphologic feature derived from 3D CNN models using whole-brain MRI has independent prognostic value for diffuse gliomas. Combining clinical, molecular genetic, and imaging data yields the best performance.

Transarterial Chemoembolization Using Idarubicin Versus Doxorubicin Chemoemulsion in Patients with Hepatocellular Carcinoma (IDADOX): Protocol for a Randomized, Non-inferiority, Double-Blind Trial

PURPOSE

This study aims to test the hypothesis that idarubicin-based transarterial chemoembolization (IDA-TACE), using one of the most potent chemotherapeutic agents, could yield oncologic outcomes equivalent to or marginally improved over doxorubicin-based TACE (DOX-TACE).

MATERIALS AND METHODS

This single-center, prospective, phase II, randomized controlled, non-inferiority, double-blind trial will enroll 128 treatment-naïve patients with HCC (≤ 5 tumors, 1-5 cm in diameter) for conventional TACE. Participants will be randomly assigned (1:1) to either IDA-TACE or DOX-TACE, with stratification by Child-Pugh class. Superselective conventional TACE will be performed using cone-beam CT and small-bore microcatheters. Patient evaluations, including dynamic imaging and blood tests, will occur at 1, 3, and 6 months post-initial treatment. The primary outcome measure is the objective response rate (ORR) according to mRECIST at 6 months. Secondary outcomes include 3-month and 6-month tumor responses, time-to-progression, the incidence of treatment-related serious adverse events within 30 days, and the incidence and severity of any adverse events.

STATISTICS

Non-inferiority will be claimed if the upper limit of a one-sided 97.5% confidence interval for the proportion difference (i.e., "6-month ORR of DOX-TACE" - "6-month ORR of IDA-TACE") falls below 0.15 in both intention-to-treat and per-protocol analyses. The proportion difference and its confidence interval will be calculated by the Cochran-Mantel-Haenszel method to obtain a weighted average of stratum-specific proportion differences.

EXPECTED GAIN OF KNOWLEDGE

If IDA-TACE demonstrates outcomes comparable to DOX-TACE, this study could provide compelling evidence that various cytotoxic agents yield similar contributions in TACE, considering the minor role of chemotherapeutic agents in TACE.

TRIAL REGISTRATION

ClinicalTrials.gov ( https://clinicaltrials.gov/ ). Identifier: NCT06114082. World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) ( https://trialsearch.who.int/Default.aspx ). Identifier: KCT0008166.

Reappraisal of Portal Vein Tumor Thrombosis as a Prognostic Factor for Patients with Hepatocellular Carcinoma

Background/Aims

: This study aimed to assess whether hepatocellular carcinoma (HCC) patients with portal vein tumor thrombosis (PVTT) could have favorable prognoses with proper treatment under selective conditions.

Methods

: This retrospective, single-center study involved 1,168 patients diagnosed with HCC between January 2005 and December 2006, before the introduction of sorafenib. Overall survival (OS) was estimated using the Kaplan-Meier method, and the Cox proportional hazards model was used to identify and adjust the variables associated with OS.

Results

: In nodular-type HCC, the OS differed significantly according to the presence of PVTT (log-rank p<0.001), and the level of PVTT, not only its presence, was a major independent factor affecting OS. PVTT at the Vp1-3 branch was associated with significantly longer OS than was PVTT at the Vp4 level (hazard ratio [HR], 1.82; 95% confidence interval [CI], 1.04 to 3.21). In multivariate analysis, the OS was further stratified according to the PVTT level and tumor type, representing that nodular HCC without PVTT exhibited the best OS, whereas nodular HCC with Vp4 PVTT (adjusted HR, 2.59; 95% CI, 1.57 to 4.28) showed a poor prognosis similar to that of infiltrative HCC. The PVTT level was consistently correlated with OS in patients treated with transarterial chemoembolization. Nodular HCC without PVTT showed the best prognosis, while nodular HCC with Vp1-3 PVTT also exhibited a favorable OS, although inferior to that without PVTT (adjusted HR, 1.47, 95% CI, 0.92 to 2.36).

Conclusions

: Active treatment such as transarterial chemoembolization can be considered for selected PVTT cases. The level of PVTT and type of HCC were independent prognostic factors.

C-Arm Computed Tomographic Image Fusion for Repetitive Transarterial Chemoembolization of Hepatocellular Carcinoma

OBJECTIVE

The aim of this study was to evaluate the potential implications of fusion imaging with C-arm computed tomography (CACT) scans for repetitive conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma.

MATERIALS AND METHODS

Fifty-six cTACE sessions were performed using fusion CACT images from September 2020 to June 2021 in a tertiary referral center, and the data were retrospectively analyzed. Fusion of unenhanced and enhanced CACT images was considered when previously accumulated iodized oil hampered the identification of local tumor progression or intrahepatic distant metastasis (indication A), when a tumor was supplied by multiple arteries with different origins from the aorta and missing tumor enhancement was suspected (indication B), or when iodized oil distribution on immediate post-cTACE CACT images needed to be precisely compared with the pre-cTACE images (indication C). Fusion image quality, initial tumor response, time to local progression (TTLP) of index tumors, and time to progression (TTP) were evaluated.

RESULTS

The fusion quality was satisfactory with a mean misregistration distance of 1.4 mm. For the 40 patients with indication A, the initial tumor responses at 3 months were nonviable, equivocal, and viable in 27 (67.5%), 4 (10.0%), and 9 (22.5%) index tumors, respectively. The median TTLP and TTP were 14.8 months and 4.5 months, respectively. For 10 patients with indication B, the median TTLP and TTP were 8.3 months and 2.6 months, respectively. Among the 6 patients with indication C, 2 patients were additionally treated at the same cTACE session after confirming incomplete iodized oil uptake on fusion imaging.

CONCLUSIONS

Fusion CACT images are useful in patients with hepatocellular carcinoma undergoing repetitive cTACE.

Prognostication and risk factor stratification for survival of patients with hepatocellular carcinoma: a nationwide big data analysis

This study was conducted to identify risk factors affecting overall survival (OS) and provide prognostication for patients with hepatocellular carcinoma (HCC) using nationwide big data. Between January 2008 and December 2014, 10,573 adult patients with new HCC were registered in a nationwide database. Among them, 6830 patients without missing data were analyzed to construct a prognostication system. A validation cohort of 4580 patients was obtained from a tertiary hospital. All patients were assumed to have received the best treatment. A conditional inference tree analysis was performed to establish a prognostic system. The C-index and calibration plot for 5-year survival were estimated for validation. As a result, the tumor burden (TB) grade was the most significant factor in determining OS, and the cutoff was TB3 (TB1‒3 versus TB4). The patients were ultimately divided into 13 prognosis groups. The C-indexes were 0.714 and 0.737 (95% confidence interval, 0.733-0.742) in the nationwide (derivation) and hospital (validation) cohorts, respectively. In the calibration plot, the 5-year survival of the validation cohort largely matched the 45-degree line. In conclusion, the proposed prognostication system with a simple tree structure enabled the detailed stratification of patient prognosis and visualized the strata of risk factors affecting OS.

Use of doxorubicin-eluting bead transarterial chemoembolization for unresectable hepatocellular carcinoma with portal vein invasion: a prospective study

Background/Aim

To evaluate the applicability of transarterial chemoembolization (TACE) treatment with doxorubicin drug-eluting beads (DEBs) in advanced hepatocellular carcinoma (HCC) patients with portal vein invasion (PVI).

Methods

This prospective study was approved by the institutional review board and informed consent was obtained from all participants. A total of 30 HCC patients with PVI received DEB-TACE between 2015 and 2018. The following parameters were evaluated: complications during DEB-TACE, abdominal pain, fever, and laboratory outcomes, including liver function change. Overall survival (OS), time to progression (TTP), and adverse events were also analyzed and assessed.

Results

DEBs measuring 100-300 μm in diameter were loaded with doxorubicin (150 mg per procedure). There were no complications during DEB-TACE and no significant differences in the levels of prothrombin time, serum albumin, or total bilirubin at follow-up compared to baseline. The median TTP was 102 days (95% confidence interval [CI], 42-207 days) and the median OS was 216 days (95% CI, 160-336 days). Three patients (10%) had severe adverse reactions, including transient acute cholangitis (n=1), cerebellar infarction (n=1), and pulmonary embolism (n=1), but no treatment-related death occurred.

Conclusions

DEB-TACE may be a therapeutic option for advanced HCC patients with PVI.

Modified design of x-ray protective clothing to enhance radiation protection for interventional radiologists

BACKGROUND

In interventional radiology procedures, the operator typically stands on the right side of the patient's right thigh to manipulate devices through the femoral sheath. Because the standard x-ray protective clothing is designed as sleeveless and scatter radiations from the patient are mainly incident from the left-anterior direction to the operator, the arm hole of the clothing may be a significant unprotected area, contributing to an increase in the operator's organ doses and effective dose.

PURPOSE

This study aimed to compare the organ doses and effective dose received by the interventional radiologist when wearing the standard x-ray protective clothing and when wearing the modified clothing with an additional shoulder guard.

METHODS

The experimental setup aimed to simulate actual clinical practice in interventional radiology. The patient phantom was located at the beam center to generate scatter radiation. An adult female anthropomorphic phantom loaded with 126 nanoDots (Landauer Inc., Glenwood, IL) was used to measure organ and effective doses to the operator. The standard wrap-around type x-ray protective clothing offered 0.25-mm lead-equivalent protection, and the frontal overlap area offered 0.50-mm lead-equivalent protection. The shoulder guard was custom-made with a material providing x-ray protection equivalent to lead of 0.50 mm thickness. The organ and effective doses were compared between the operator wearing the standard protective clothing and the one wearing the modified clothing with a shoulder guard.

RESULTS

After adding the shoulder guard, doses to the lungs, bone marrow, and esophagus decreased by 81.9%, 58.6%, and 58.7%, respectively, and the effective dose to the operator decreased by 47.7%.

CONCLUSIONS

Widespread use of modified x-ray protective clothing with shoulder guards can significantly decrease the overall occupational radiation risk in interventional radiology.

Transarterial chemoembolization as an alternative to radioembolization is associated with earlier tumor recurrence than in radioembolization-eligible patients

Introduction

Although transarterial radioembolization (TARE) using yttrium-90 (⁹⁰Y) is a treatment option for large hepatocellular carcinoma (HCC), a fraction of patients are ineligible for TARE due to high lung shunt fraction (LSF).

Methods

We evaluated if treatment with transarterial chemoembolization (TACE), owing to TARE ineligibility was associated with early HCC progression. Consecutive patients with HCC who were initially TARE candidates were included. Patients with vascular invasion or metastasis were excluded. Primary endpoints were time-to-progression (TTP) and overall survival (OS). The secondary endpoint was objective response rate.

Results

In total, 175 patients were included: 144 underwent TARE (TARE-eligible group) and 31 underwent TACE due to high LSF (TARE-ineligible group). This latter group had larger tumors (13.8 cm vs. 7.8 cm, P<0.001) and higher MoRAL scores (1,385.8 vs. 413.3, P=0.002) than the TARE-eligible group. After balancing baseline characteristics with an inverse probability of treatment weighting (IPTW), the TARE-ineligible group showed shorter TTP [adjusted hazard ratio (aHR)=2.16, 95% confidence interval (CI)=1.14-4.07, P=0.02] and OS (aHR=1.80, 95% CI=0.85-3.80, P=0.12), although the latter was not statistically significant. The TARE-ineligible group had a significantly lower objective response rate than the TARE-eligible group (9.7% vs. 56.9%, P<0.001).

Conclusion

TARE-ineligible patients had larger tumors and higher MoRAL scores than TARE-eligible patients. Treatment with TACE, owing to high LSF, was associated with a shorter TTP even after balancing tumor size and MoRAL scores.

Drug delivery in transarterial chemoembolization of hepatocellular carcinoma: Ex vivo evaluation using transparent tissue imaging

In this study, we elucidated for the first time the role of anti-cancer drugs in transarterial chemoembolization (TACE) via direct visualization of the spatial distribution of drugs with respect to blood vessels in intact transparent hepatocellular carcinoma (HCC) tissues. To date, precise estimation of drug penetration into tumors using thin 3D tissue sections has been challenging. This study utilized the tissue optical clearing technique to resolve the lack of tissue clarity, thereby enabling deep tissue imaging for the quantitative assessment of drug delivery following TACE. We compared the drug delivery effect, time-dependent embolic effect, and immunogenic response following conventional TACE (cTACE), drug-eluting embolic TACE (DEE-TACE), and transarterial embolization (TAE) in a rat model of HCC. After each treatment, three-dimensional drug delivery was quantitatively evaluated via the transparent liver tumor imaging, and time-dependent tumor necrosis was analyzed by serial tumor harvesting and histological staining. The results showed that chemotherapeutic agents travel only short distances after cTACE (∼80µm) and DEE-TACE (∼110µm), whereas necrosis occurs extensively within 24 h of treatment (85.3-97.2% of tumor cells). In addition, the percentages of CD4 and IL-17+ CD4 T cells increased significantly following treatment; however, drug-loading did not appear to affect the immune response following TACE. In conclusion, transarterially delivered chemotherapeutic agents appeared to exert a limited role, owing to the rapid and overwhelming effect of embolization. STATEMENT OF SIGNIFICANCE: TACE has been widely used for the treatment of HCC, especially for unresectable intermediate and advanced HCCs. Drug use in TACE is expected to provide patients with synergistic therapeutic benefits with the effect of embolic agents; however, the role of chemotherapeutic agents in TACE remains controversial. This study quantitatively verified that chemotherapeutic agents travel only short distances after TACE, while necrosis occurs extensively within 24h, and drug loading does not significantly affect immune responses following TACE. Three-dimensional imaging of intact transparent HCC can contribute to a better understanding of drug delivery mechanisms associated with TACE and also reveal that drug use in TACE may need to be reconsidered and limited to situations when embolization is expected to be insufficient.

Clinical course and role of embolization in patients with spontaneous rupture of hepatocellular carcinoma

Background

A diverse clinical course after the spontaneous rupture of hepatocellular carcinoma (HCC) renders nonstandardized treatment protocols.

Purpose

To evaluate clinical course and role of transcatheter arterial embolization (TAE) in patients with rupture of HCC.

Materials and methods

This retrospective study included 127 patients who were treated for ruptured HCC at single institution between 2005 and 2014. After multidisciplinary discussion, patients underwent medical management, TAE, emergency surgery or staged surgery. Patients were retrospectively divided into two groups based on the intent of treatment: curative and palliative. The rebleeding rate and 1-month and overall survival (OS) were compared between two groups. The incidence and survival of patients with intraperitoneal drop metastasis (IPDM) were also analyzed.

Results

The overall rebleeding rate in patients who underwent TAE was 3.1% (3/96). One-month mortality rate was 6.3% (8/127). The rebleeding and 1-month mortality rates were not significantly different between two groups. OS was significantly higher in the curative treatment group (median: 12.0 vs 2.2 months, p&lt;0.001). Among 96 patients who initially received TAE, ten patients underwent staged operation (10.4%). The median OS for medical management, TAE, emergency surgery and staged surgery was 2.8, 8.7, 19.1 and 71.1 months, respectively. Of all patients, 15.2% developed IPDM mostly within 1 year and their survival was poorer than that of patients without IPDM (median: 6.3 vs. 15.1 months, p&lt;0.001).

Conclusion

TAE provided effective immediate hemostasis with a low rebleeding rate and may serve as a bridge to elective surgery. IPDM frequently occurred within 1 year and manifested poor survival; thus, close surveillance should be considered for patients with spontaneous rupture of HCC.

Summary of key guidelines for locoregional treatment of HCC in Asia, Europe, South and North America

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide accounting for over 800,000 new cases in 2018, with the highest incidence in Asia and Africa where hepatitis B is the most common risk factor. In Europe, Japan, and the United States, hepatitis C chronic alcohol abuse and non-alcoholic fatty liver disease are more common risk factors. Five-year survival is low, less than 20% worldwide. HCC is a particularly challenging disease to treat because therapeutic options and prognosis must also consider hepatitis or cirrhosis independent of the malignancy. Locoregional therapies (LRT) including ablation, arterially directed therapy and external beam radiation are the preferred treatments for patients with good performance status, unresectable disease limited to the liver and preserved liver function. In practice, patients with portal vein tumor thrombus and limited extrahepatic disease may also be considered candidates for LRT. There are several guidelines developed by expert panels provide recommendations on treating this challenging disease including the Barcelona Clinic Liver Cancer, European Association for the Study of the Liver, European Society for Medical Oncology, American Association for the Study of the Liver Diseases, and the National Comprehensive Cancer Network. The purpose of this paper is to review the guidelines as they are applied clinically in regions with high incidence of HCC.

Initiative on Superselective Conventional Transarterial Chemoembolization Results (INSPIRE)

Several publications show that superselective conventional TransArterial ChemoEmbolization (cTACE), meaning cTACE performed selectively with a microcatheter positioned as close as possible to the tumor, improves outcomes, maximizing the anti-tumoral effect and minimizing the collateral damages of the surrounding liver parenchyma. Recent recommendations coming from the European Association for the Study of the Liver (EASL) and European Society of Medical Oncology (ESMO) highlighted that TACE must be used in Hepatocellular Carcinoma (HCC) “selectively targetable” and “accessible to supraselective catheterization.” The goal of the manuscript is to better define such population and to standardize superselective cTACE (ss-cTACE) technique. An expert panel with extensive clinical-procedural experience in TACE, have come together in a virtual meeting to generate recommendations and express their consensus. Experts recommend that anytime cTACE is proposed, it should be ss-cTACE, preferably with a 1.5–2.0 Fr microcatheter. Ideally, ss-cTACE should be proposed to patients with less than five lesions and a maximum number of two segments involved, with largest tumor smaller than 5 cm. Angio Cone-Beam Computed Tomography (CBCT) should be used to detect enhancing tumors, tumor feeders and guide tumor targeting. Whole tumor volume should be covered to obtain the best response. Adding peritumoral margins is encouraged but not mandatory. The treatment should involve a water-in-oil emulsion, whose quality is assessable with the “drop test.” Additional particulate embolization should be systematically performed, as per definition of cTACE procedure. Non-contrast CBCT or Multi-Detector Computed Tomography (MDCT) combined with angiography has been considered the gold standard for imaging during TACE, and should be used to assess tumor coverage during the procedure. Experts convene that superselectivity decreases incidence of adverse effects and improves tolerance. Experts recommend contrast-enhanced Computed Tomography (CT) as initial imaging on first follow-up after ss-cTACE, and Magnetic Resonance Imaging (MRI) if remaining tumor viability cannot be confidently assessed on CT. If no response is obtained after two ss-cTACE sessions within six months, patient must be considered unsuitable for TACE and proposed for alternative therapy. Patients are best served by multidisciplinary decision-making, and Interventional Radiologists should take an active role in patient selection, treatment allocation, and post-procedural care.

Bronchial and non-bronchial systemic artery embolization with transradial access in patients with hemoptysis

PURPOSE We aimed to determine the safety and feasibility of transradial access (TRA) in bronchial artery and non-bronchial systemic artery (NBSA) embolization in patients with non-massive hemoptysis. METHODS This retrospective study was approved by the Institutional Review Board. Among the 300 patients treated for hemoptysis with bronchial artery and NBSA embolization between April 2018 and July 2019, 19 procedures in 19 patients were conducted by TRA and were retrospectively analyzed. TRA was considered when the bronchial artery or NBSA originated from the arch vessel or its tributaries. The exclusion criteria of TRA included Barbeau C or D waveform and a radial artery diameter of less than 1.8 mm on ultrasound. TRA was also avoided in cases of the high-origin bronchial artery (i.e., T4 or higher level of the aorta). The hemoptysis-free time was estimated using the Kaplan-Meier method. RESULTS The technical success (i.e., embolization of all target artery with TRA) rate was 94.7% (18 out of 19 patients). In terms of the target arteries, embolization with TRA was technically successful in treating 47 out of 48 arteries (97.9%). The 1-month and 6-month hemoptysis-free rates were 89.5% (17/19) and 73.7% (14/19), respectively. The only adverse event was iatrogenic dissection of the bronchial artery with little clinical significance in 1 patient. No access site complications were identified on post-procedure day 1 ultrasonography. CONCLUSION With proper patient selection, TRA offers a safe and effective approach to embolize the bronchial arteries and NBSAs in patients with hemoptysis.

Radioembolization for Hepatocellular Carcinoma: The Effects of Arterioportal Shunts on Nontargeted Liver Hypertrophy

PURPOSE

To determine whether arterioportal shunting to the contralateral lobe attenuates the liver function and the hypertrophy of the nontargeted liver after radioembolization in patients with hepatocellular carcinoma (HCC) MATERIALS AND METHODS: This retrospective study included 46 patients who received radioembolization for HCC contained within the right lobe between 2012 and 2020. The patients were divided into the following groups based on the presence and extent of arterioportal shunt : patients with retrograde arterioportal shunting to the left lobe (contralateral group) and patients with arterioportal shunt limited to the right lobe or no arterioportal shunt (control group). Safety profiles including adverse events, tumor response and overall survival were compared. With the volume of left lateral segment used as a surrogate marker for nontarget liver, degree of hypertrophy was compared between two groups at 3 and 6 months.

RESULTS

Liver function significantly deteriorated in contralateral group in a month (p=<0.05). Tumor response and overall survival did not significantly differ between two groups. Degree of hypertrophy was significantly higher in the control group compared with the contralateral group at 3 months [10.6% vs 3.5% (p = 0.008)] and at 6 months [20.7% vs 2.4% (p < 0.001)].

CONCLUSION

In patients with arterioportal shunting to the contralateral lobe, hypertrophy of the nontarget liver may not occur and the liver function may be worsened.

ABC-HCC: A phase IIIb, randomized, multicenter, open-label trial of atezolizumab plus bevacizumab versus transarterial chemoembolization (TACE) in intermediate-stage hepatocellular carcinoma

TPS498

Background: Hepatocellular carcinoma (HCC) is among the most common and deadliest cancers worldwide. In the intermediate stage the current standard of care is locoregional treatment with transarterial chemoembolization (TACE). The IMbrave150 phase 3 study has demonstrated that the combination of atezolizumab, an anti-PD-L1 antibody, and bevacizumab, an anti-VEGF antibody (atezo/bev), extends survival in comparison to sorafenib in the first-line setting in advanced HCC[1] which has led to its approval for patients with unresectable HCC. However, it is unknown whether atezo/bev is more efficacious than TACE for the treatment of intermediate HCC. ABC-HCC (NCT04803994) is a phase 3b, randomized, multicenter, open-label, investigator-initiated trial of atezo/bev versus TACE in intermediate stage HCC with high tumor burden exceeding the Milan criteria. Methods: The ABC-HCC study is recruiting patients ≥18 years of age who have a confirmed diagnosis of HCC in the intermediate stage (multifocal, exceeding the Milan criteria, no extrahepatic spread, no macrovascular invasion) and no curative treatment option. In addition, patients must have an ECOG performance status of 0, preserved liver function (Child-Pugh A), and ≥2 untreated lesions with a diameter > 10 mm and arterial hyperenhancement on cross-sectional imaging. Those who have previously received locoregional or systemic treatment are excluded. 434 patients will be randomly assigned 1:1 to systemic treatment (atezo at 1200 mg IV plus bev at 15 mg/kg IV) once every three weeks or to TACE. Both conventional and DEB-TACE are allowed. Region, AFP level (< 200 ng/mL vs. ≥200 ng/mL), and ALBI (1 vs. 2) will be used for stratification. Cross-sectional imaging (CT/MRI) will be performed every 8 weeks to determine the time to failure of treatment strategy, a novel primary endpoint. Failure of strategy is reached in case of progressive disease and any of the following: loss of clinical benefit, unacceptable toxicity, liver function deterioration, and therapy not further applicable for other reasons. Secondary endpoints are overall survival (OS), OS rate at 24 months, objective response rate, time to progression, time to loss of systemic treatment options, progression-free survival, duration of treatment, duration of response, time to deterioration of liver function, safety, and quality of life (EORTC QLQ-C30 and HCC18). Patients will be followed for survival, quality of life and subsequent anti-cancer therapy every 12 weeks after the end of study treatment. Recruitment for this study began in July 2021. FF, RK, JB and PRG contributed equally. References: 1. Finn RS, Qin S, Ikeda M, Galle PR, Ducreux M, Kim TY, et al. Atezolizumab plus Bevacizumab in Unresectable Hepatocellular Carcinoma. N Engl J Med. 2020;382(20):1894-905. doi: 10.1056/NEJMoa1915745. Clinical trial information: NCT04803994.

A Prognostic Prediction Model of Transarterial Radioembolization in Hepatocellular Carcinoma: SNAP-HCC

BACKGROUND

Prognosis prediction in patient with hepatocellular carcinoma (HCC) after transarterial radioembolization (TARE) remains difficult. The aim of this study was to develop a prognostic model to aid in the decision to use TARE.

METHODS

A total of 174 patients in Korea who underwent TARE for HCC as the initial treatment were included. We developed a prediction model for overall survival (OS) based on independent risk factors for OS and validated the model by bootstrap method.

RESULTS

The median maximal size of the tumors was 8.2 cm, the median number of tumors was 2, and the median albumin level was 4.0 g/dL. Portal vein tumor thrombosis was found in 46.0% (Vp1-3 [39.7%] and Vp4 [6.3%]). Four independent risk factors associated with OS (maximal tumor size, tumor number, albumin, and portal vein tumor thrombosis) were used to develop the SNAP-HCC score. Bootstrap validation of the scoring index determined that the Harrell's c-index for OS was 0.756 (95% confidence interval: 0.729-0.783). Patients grouped based on their SNAP-HCC (scores 0-5) were well discriminated, with significant differences between the groups (all P < 0.05). Patients with SNAP-HCC < 3 showed significantly longer OS than patients with SNAP-HCC ≥ 3 (P < 0.001). The respective survival probabilities at years 1 and 3 were 0.81 and 0.73 in the low-risk (SNAP-HCC < 3) and 0.32 and 0.14 in the high-risk (SNAP-HCC ≥ 3) patients.

CONCLUSIONS

The SNAP-HCC scoring system predicted the outcome of HCC patients undergoing TARE as an initial treatment. This model could be helpful for initial planning the treatment of HCC patients.

Yttrium-90 Radioembolization Is Associated with Better Clinical Outcomes in Patients with Hepatocellular Carcinoma Compared with Conventional Chemoembolization: A Propensity Score-Matched Study

Background

Both trans-arterial radioembolization (TARE) and conventional trans-arterial chemoembolization (TACE) can effectively control hepatocellular carcinoma (HCC) in patients who are not suitable for curative resection. This study compared the effectiveness of TARE and conventional TACE as the initial trans-arterial treatment for hepatocellular carcinoma (HCC) assessed by tumor response and clinical outcomes.

Material and Methods

Data were retrospectively analyzed the propensity score-matched cohort for overall survival (OS), progression-free survival (PFS), and intrahepatic PFS in patients who have received TARE or TACE as the first HCC treatment from March 2012 to December 2017.

Results

A total of 138 patients initially treated with TARE (n = 54) or TACE (n = 84) was included in this study. Of 138 patients, median age was 59 years and the mean follow-up period was 27.6 months. TARE showed better OS (hazard ratio [HR] = 0.54, 95% confidence interval [CI] = 0.31–0.92, log-rank P = 0.02), better PFS (HR = 0.51, 95% CI = 0.36–0.97, log-rank P = 0.04), and better intrahepatic PFS (HR = 0.51, 95% CI = 0.30–0.88, log-rank P = 0.01) compared with TACE. TARE was an independent prognostic factor for OS (adjusted HR [aHR] = 0.52, 95% CI = 0.30–0.90, P = 0.02), PFS (aHR = 0.57, 95% CI = 0.35–0.94, P = 0.03), and intrahepatic PFS (aHR = 0.49, 95% CI = 0.28–0.84, P = 0.01).

Conclusion

TARE as initial trans-arterial treatment is associated with better clinical outcomes such as longer OS compared with TACE in patients with HCC.

Chemoembolization for Hepatocellular Carcinoma in Patients With Inferior Vena Caval/Right Atrial Tumor Thrombi Without Hepatic Vein Invasion

AIM

To clarify the clinical and radiological features of isolated tumor thrombi in the inferior vena cava (IVC)/right atrium in patients with hepatocellular carcinoma (HCC) without hepatic vein invasion.

PATIENTS AND METHODS

In this retrospective study, from January 2007 to December 2019, a total of 35,163 chemoembolization sessions were performed in 7,704 patients with HCC. Among them, 10 (0.13%) patients had tumor thrombi in the IVC/right atrium without definitive hepatic vein invasion. Computed tomographic (CT) scans, digital subtraction angiograms, and cone-beam CT images were retrospectively reviewed and interpreted.

RESULTS

The tumor thrombi were supplied by the right inferior phrenic artery (n=8) or the right internal mammary artery (n=2). Follow-up CT scans in eight patients showed linear accumulation of iodized oil along the diaphragm, which was presumed to be a thrombosis of the phrenic vein. Retrospective review of formal radiological reports of pre-procedural CT scans revealed that a correct diagnosis of tumor thrombi of the IVC/right atrium was made in only three cases.

CONCLUSION

HCC invading the phrenic vein may have tumor thrombi in the IVC/right atrium without hepatic vein invasion.

Anatomic Variations of the Hepatic Artery in 5625 Patients

Purpose

To analyze the origin and anatomic course of the hepatic arteries by using digital subtraction angiography (DSA) and multidetector CT in a large study sample.

Materials and Methods

This retrospective study included 5625 patients who underwent liver CT and chemoembolization between January 2005 and December 2018 (mean age, 60 years ± 11 [range, 11-99 years]; 4464 males). The CT and DSA images were reviewed to evaluate the visceral arterial anatomy for variations in the celiac axis and hepatic arteries. Aberrant right hepatic arteries (aRHAs) and aberrant left hepatic arteries (aLHAs) were defined on the basis of their origin and anatomic course. Statistical analyses were performed to evaluate the association between aRHAs and aLHAs and the association between variations in the hepatic artery and celiac axis.

Results

Right hepatic arteries were categorized as being aRHAs (if originating from the proximal to middle common hepatic artery, gastroduodenal artery, superior mesenteric artery [SMA], celiac axis, aorta, splenic artery, or left gastric artery [LGA]) or as being aLHAs (if arising from the LGA, celiac axis, aorta, or SMA). The prevalence of aRHAs (15.63%; 879 of 5625) and the prevalence aLHAs (16.32%; 918 of 5625) were similar. Patients with an aRHA were more likely to have an aLHA than those without an aRHA (29.01% vs 13.97%; P < .001), and patients with an aLHA were more likely to have an aRHA than those without an aLHA (27.78% vs 13.26%; P < .001). There was no association between the hepatic arterial variations and celiac axis variations. A hypothetical anatomic model summarizing the observed variations was created.

Conclusion

A comprehensive list of hepatic arterial variations and a three-dimensional hypothetical model for the observed variations were described.Keywords: CT, Angiography, Liver, Anatomy, Arteries© RSNA, 2021 Supplemental material is available for this article. See also commentary by Sutphin and Kalva in this issue.

Lung Shunt Reduction for Yttrium-90 Radioembolization: Chemoembolization Versus Radioembolization

AIM

To evaluate the efficacy of chemoembolization versus radioembolization in reducing lung shunt fraction (LSF) in patients with hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

In this retrospective study, from March 2012 to January 2021, 457 patients with HCC underwent planning angiography and ^99mTc-macroaggregated albumin imaging for possible yttrium-90 radioembolization. Ten patients underwent radioembolization, and seven patients underwent conventional chemoembolization for LSF reduction, and a second ^99mTc-macroaggregated albumin imaging was obtained approximately 1 month later. LSF under both procedures was compared with the Mann-Whitney U-test and the Wilcoxon signed-rank test.

RESULTS

In the radioembolization group, the mean first and second LSF were 13.0±6.9% and 20.9±9.6%, respectively (p=0.059); after radioembolization, LSF was lower in three patients but higher in seven patients. In the chemoembolization group, the mean first and second LSF were 26.1±17.3% and 8.7±5.5%, respectively (p=0.018); after chemoembolization, LSF was reduced in all seven patients.

CONCLUSION

Chemoembolization appears to be more effective in reducing LSF within 1 month compared with radioembolization.

Effectiveness of Transarterial Chemoembolization-First Treatment for Advanced Hepatocellular Carcinoma: A Propensity Score Matching Analysis

Background

Still in real-world practice, advanced hepatocellular carcinoma (HCC) patients are treated with transarterial chemoembolization (TACE). This study compared the therapeutic effectiveness of initial TACE treatment and initial sorafenib treatment in advanced HCC patients.

Patient and Methods

Advanced HCC patients initially treated with sorafenib or TACE were included in this study. Treatment crossover due to an unfavorable response to initial treatment was allowed. Propensity score (PS) matching was applied for balancing baseline characteristics. The primary outcome was overall survival (OS) and the secondary outcomes included tumor response.

Results

A total of 554 patients were included in this study: 85 were initially treated with sorafenib (the sorafenib-first group) and 469 with TACE (the TACE-first group). In the entire cohort, the TACE-first group was associated with lower risk of death [adjusted hazard ratio (HR)=0.75, P=0.04]. In the PS-matched cohort (85 patients per group), the TACE-first group showed longer OS than the sorafenib-first group in both univariable (HR=0.68, P=0.02) and multivariable analyses (adjusted HR=0.58, P=0.002). Specifically, within both the entire and the PS-matched cohorts, the TACE-first group showed longer OS in subgroups with major portal vein tumor thrombosis (HR=0.72, P=0.048; HR=0.52, P=0.003) or infiltrative HCC (HR=0.42, P<0.001; HR=0.30, P=0.004, respectively). The objective response rate was higher in the TACE-first group (29.3% vs 14.7%, P=0.03) within the PS-matched cohort.

Conclusion

For advanced HCC, initial TACE leads to longer OS with a more favorable tumor response than initial sorafenib treatment. Intrahepatic tumor control with initial locoregional therapy may be a potent strategy for advanced HCC.

Prospective Multi-Center Korean Registry of Transcatheter Arterial Chemoembolization with Drug-Eluting Embolics for Nodular Hepatocellular Carcinoma: A Two-Year Outcome Analysis

Objective

To assess the two-year treatment outcomes of chemoembolization with drug-eluting embolics (DEE) for nodular hepatocellular carcinoma (HCC).

Materials and Methods

This study was a prospective, multicenter, registry-based, single-arm trial conducted at five university hospitals in Korea. Patients were recruited between May 2011 and April 2013, with a target population of 200. A DC Bead loaded with doxorubicin was used as the DEE agent. Patients were followed up for two years. Per-patient and per-lesion tumor response analysis, per-patient overall survival (OS) and progression-free survival (PFS) analysis, and per-lesion tumor control analysis were performed.

Results

The final study population included 152 patients, with 207 target lesions for the per-lesion analysis. At one-month, six-month, one-year, and two-year per-patient assessments, complete response (CR) rates were 40.1%, 43.0%, 33.3%, and 19.6%, respectively. The objective response (OR) rates were 91.4%, 55.4%, 35.1%, and 19.6%, respectively. The cumulative two-year OS rate was 79.7%. The cumulative two-year PFS rate was 22.4% and the median survival was 9.3 months. In multivariable analysis, the Child-Pugh score (p = 0.019) was an independent predictor of OS, and tumor multiplicity (p < 0.001), tumor size (p = 0.020), and Child-Pugh score (p = 0.006) were independent predictors of PFS. In per-lesion analysis, one-month, six-month, one-year and two-year CR rates were 57.5%, 58.5%, 45.2%, and 33.3%, respectively, and the OR rates were 84.1%, 65.2%, 46.6%, and 33.3%, respectively. The cumulative two-year per-lesion tumor control rate was 36.2%, and the median time was 14.1 months. The Child-Pugh score (p < 0.001) was the only independent predictor of tumor control. Serious adverse events were reported in 11 patients (7.2%).

Conclusion

DEE chemoembolization for nodular HCCs in the Korean population showed acceptable survival, tumor response, and safety profiles after a two-year follow-up. Good liver function (Child-Pugh score A5) was a key predictor of per-patient OS, PFS, and per-lesion tumor control.

Combination of 1st and 2nd Week Dosing of Glass Yttrium-90 Microspheres for Superselective Radioembolization

BACKGROUND/AIM

The aim of this study was to address the feasibility of combination of 1^st and 2^nd week dosing of glass microspheres in the setting of selective radioembolization for large hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Yttrium-90 radioembolization was performed in 53 patients with single nodular hepatocellular carcinomas larger than 5 cm. A total of 32 patients underwent radioembolization with glass microspheres from a single calibration date (single-dosing group), and 21 patients were treated with a combination of 1^st and 2^nd week dosing of glass microspheres (combined-dosing group). In the combined-dosing group, the lobar hepatic arteries and subsidiary tumor-feeding arteries were commonly treated with 1^st and 2^nd week dosing of glass microspheres, respectively.

RESULTS

The combined-dosing group tended to have a lower frequency of pain requiring analgesics without statistical significance (p=0.085). The objective response rate at 3 months in single-dosing group and combined-dosing group was 46.9% (15 out of 32) and 66.7% (14 out of 21), respectively.

CONCLUSION

The combined 1^st and 2^nd week dosing of glass microspheres demonstrated an acceptable toxicity and tumor response when both a lobar hepatic artery and a small tumor-feeding artery need to be treated in one session.

Yttrium-90 Radioembolization for Hepatocellular Carcinoma: Virtual Tumor Absorbed Dose as a Predictor of Complete Response

BACKGROUND/AIM

To evaluate the impact of virtual tumor absorbed dose (vTAD) on tumor response in patients with hepatocellular carcinoma (HCC) treated with yttrium-90 radioembolization.

PATIENTS AND METHODS

The institutional review board approved this retrospective single center study, which comprised 100 patients with nodular HCC who underwent yttrium-90 radioembolization between November 2015 and December 2019. The vTAD was calculated assuming that all infused microspheres were distributed only in the tumor. The ability of mean absorbed dose (mAD) and vTAD in predicting complete response were evaluated by receiver operating characteristic (ROC) curve analyses.

RESULTS

The mAD was 263.9 Gy ± 125.8, and the mean vTAD was 2005.8 Gy ± 2348.9. In terms of tumor response, 63 patients had complete response, 25 partial response, and 12 stable disease. For predicting complete response, ROC curve analyses revealed that the area under the curve (AUC) value of the vTAD was significantly higher (p<0.001) than that of the mAD. Multivariate analysis revealed that Child-Pugh class A5, unilobar disease, and vTAD (>952 Gy) were significant factors in predicting complete response.

CONCLUSION

High vTAD (>952 Gy) plays a significant role in complete response in patients with nodular HCC.

Development and evaluation of an ultrasound-triggered microbubble combined transarterial chemoembolization (TACE) formulation on rabbit VX2 liver cancer model

Transarterial chemoembolization (TACE) is an image-guided locoregional therapy used for the treatment of patients with primary or secondary liver cancer. However, conventional TACE formulations are rapidly dissociated due to the instability of the emulsion, resulting in insufficient local drug concentrations in the target tumor.

Methods: To overcome these limitations, a doxorubicin-loaded albumin nanoparticle-conjugated microbubble complex in an iodized oil emulsion (DOX-NPs-MB complex in Lipiodol) has been developed as a new ultrasound-triggered TACE formulation.

Results: (1) Microbubbles enhanced therapeutic efficacy by effectively delivering doxorubicin- loaded nanoparticles into liver tumors via sonoporation under ultrasound irradiation (US+). (2) Microbubbles constituting the complex retained their function as an ultrasound contrast agent in Lipiodol. In a rabbit VX2 liver cancer model, the in vivo study of DOX-NPs-MB complex in Lipiodol (US+) decreased the viability of tumor more than the conventional TACE formulation, and in particular, effectively killed cancer cells in the tumor periphery.

Conclusion: Incorporation of doxorubicin-loaded microbubble in the TACE formulation facilitated drug delivery to the tumor with real-time monitoring and enhanced the therapeutic efficacy of TACE. Thus, the enhanced TACE formulation may represent a new treatment strategy against liver cancer.

Varices on computed tomography as predictor of survival after hepatic resection in patients with single hepatocellular carcinoma

BACKGROUND AND AIM

The aim of this study was to evaluate whether presence of varices on computed tomography (CT) could predict treatment outcome for hepatocellular carcinoma patients.

METHODS

We enrolled 241 patients with single hepatocellular carcinoma ≤ 5 cm treated by surgery. With the use of preoperative CT/endoscopy, patients were classified into the following: presence of standard clinically significant portal hypertension (CSPH) surrogate, defined as varices on esophagogastroduodenoscopy and/or thrombocytopenia with splenomegaly (group 1, n = 47); varices on CT without standard CSPH surrogate (group 2, n = 45); and none of both (group 3, n = 149). Development of posthepatectomy liver failure and overall survival (OS) were evaluated for each patient group, and patients were re-classified into two groups according to presence of CT-enhanced CSPH surrogate, defined as standard surrogate and/or varices on CT. Predictive power of each survival model was compared using Harrell's C-index.

RESULTS

Posthepatectomy liver failure rate in group 2 was similar to that in group 1 (53.3% [24/45] vs. 55.3% [26/47]; P = 1.000) but significantly higher than that in group 3 (53.3% [24/45] vs. 28.2% [42/149], P = 0.002). Seven-year OS rates in group 2 were similar to those in group 1 (55.6% vs. 60.8%, P = 0.988) but significantly lower than those in group 3 (55.6% vs. 83.3%, P = 0.001). Presence of standard CSPH surrogate (hazard ratio = 1.89 [1.08-3.30], P = 0.025) and CT-enhanced CSPH surrogate (hazard ratio = 2.60 [1.56-4.39], P < 0.001) were significant predicting factor for OS. However, CT-enhanced CSPH surrogate had significantly higher Harrell's C-index than standard surrogate (0.619 vs. 0.553, P = 0.034).

CONCLUSION

The presence of CT-enhanced CSPH surrogate including varices on CT was the significant predictive of poor OS, providing better predictive power than standard surrogate.

Benign Biliary Stricture after Yttrium-90 Radioembolization for Hepatocellular Carcinoma

PURPOSE

To determine the frequency and possible causative factors of benign biliary stricture after radioembolization in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This retrospective study comprised 232 patients with HCC who underwent yttrium-90 radioembolization between October 2015 and September 2019. Benign biliary stricture was defined as biliary ductal dilatation of segmental or lobar biliary ducts on follow-up images. Clinical and radiologic characteristics were compared using χ² test or independent t test.

RESULTS

Mean target perfused tissue dose was 224.6 Gy ± 106.8 (median, 205.7 Gy; range, 47.0-694.7 Gy). Of 232 patients, 15 (6.5%) had benign biliary stricture, which was detected from 3 weeks to 10.3 months (mean, 3.9 months; median, 3.2 months). Whereas 5 patients did not have any symptoms or signs associated with benign biliary stricture, 10 patients had cholangitis and/or laboratory abnormality requiring biliary drainage procedures and intravenous antibiotic therapy. Selective radioembolization through a caudate artery was performed in 55 (23.7%) patients. The incidence of benign biliary stricture was 16.4% (9/55) and 3.4% (6/177) in patients with and without selective radioembolization through a caudate artery, respectively (P = .002).

CONCLUSIONS

Benign biliary stricture following yttrium-90 radioembolization may be common among patients receiving selective treatment via a caudate artery.

Feasibility of dosimetric measurements using Al2O3:C OSL dosimeter during fluoroscopy-guided procedures

This study investigated the feasibility of dosimetric measurements using Al2O3:C optically stimulated luminescence (OSL) dosimeters during fluoroscopy-guided procedures. The linearity and energy dependence of Al2O3:C OSL dosimeters were evaluated, and the air kerma rate at the operator's position was measured. The response of Al2O3:C OSL dosimeters to short, repetitive irradiations was compared to that of long uninterrupted irradiation. The change in response of the Al2O3:C OSL dosimeter under automatic exposure rate control (AERC) was evaluated with the use of various thicknesses of polymethyl-methacrylate (PMMA) plates (15-30 cm). The Al2O3:C OSL dosimeters could detect 5µGy and showed good linearity in doses of ≥10µGy (R²: 0.997-0.999,p< 0.001). The relative response of the Al2O3:C OSL dosimeter normalised to that of 36.8 keV was 0.828-1.101 at the energies investigated (30.6-46.0 keV). The air kerma rate at the operator's position was estimated to be 2.61-7.17µGy min^-1depending on the heights representing different body parts. Repetitive short irradiations had no significant impact on the relative response of the Al2O3:C OSL dosimeters (p> 0.05). Despite a high energy dependence on the low energy beam used in fluoroscopy, the change in relative response of the Al2O3:C OSL dosimeter under AERC was within 5.7% depending on the thickness of the PMMA plates. Dosimetric measurement using Al2O3:C OSL dosimeters for patients and operators is feasible. However, one should be cautious about high standard deviations when measuring small doses of ≤20µGy using Al2O3:C OSL dosimeters. It is essential to perform intensive bleaching before measuring very small doses to minimise pre-irradiation counts.

Spectral CT-Based Iodized Oil Quantification to Predict Tumor Response Following Chemoembolization of Hepatocellular Carcinoma

PURPOSE

To quantify iodized oil retention in tumors after transarterial chemoembolization using spectral computed tomography (CT) imaging in patients with hepatocellular carcinoma (HCC) and evaluate its performance in predicting 12-month tumor responses.

MATERIALS AND METHODS

From September 2017 to December 2018, 111 patients with HCC underwent initial conventional transarterial chemoembolization. Immediately after the procedure, unenhanced CT was performed using a spectral CT scanner, and the iodized oil densities in index tumors were measured. In tumor-level analyses, a threshold level of iodized oil density in the tumors was calculated using clustered receiver operating characteristic curve analyses to predict the 12-month tumor responses. In patient-level analyses, significant factors associated with a 12-month complete response, including the presence of tumors below the threshold value (ie, suspected residual tumors), were evaluated by logistic regression.

RESULTS

Forty-eight HCCs in 39 patients were included in the analyses. The lower 10th percentile of the iodine density was identified as the threshold for determining the 12-month nonviable responses. The area under the curve of the iodine density measurements in predicting the 12-month nonviable responses was 0.893 (95% confidence interval, 0.797-0.989). The threshold value of the iodine density of 10.68 mg/mL yielded a sensitivity of 82.76% and specificity of 94.74% (P < .001). In the patient-level analysis, the 12-month complete response was significantly associated with the presence of a suspected residual tumor, with an odds ratio of 72.0 (95% confidence interval, 7.273-712.770).

CONCLUSIONS

Spectral CT imaging using quantitative analysis of the iodized oil retention in target HCCs can predict tumor responses after a conventional transarterial chemoembolization procedure.

The Value of Preprocedural MR Imaging in Genicular Artery Embolization for Patients with Osteoarthritic Knee Pain

PURPOSE

To determine the value of preprocedural MR imaging in genicular artery embolization (GAE) for patients with osteoarthritic knee pain.

MATERIALS AND METHODS

This single-center study retrospectively analyzed 28 knees in 18 patients who underwent GAE for intractable knee pain < 1 month after MR imaging. The pain experienced in each knee was evaluated on a 100-mm visual analog scale (VAS) at baseline and 1- and 3-month after GAE. "GAE responders" were defined as knees that exhibited greater than 30% reduction of VAS pain scores from baseline at both follow-up visits. Musculoskeletal radiologists evaluated MR images of the affected knee compartment regarding cartilage defects, osteophytes, subchondral cysts, bone marrow lesions (BMLs), meniscal injury, and joint effusion. The performances of Kellgren-Lawrence (KL) grading and MR findings in predicting GAE responders was estimated based on receiver operating characteristic curves.

RESULTS

The mean VAS pain score was 84.3 mm. BML (area under the curve [AUC], 0.860; P < .001), meniscal injury (AUC, 0.811; P = .003), and KL grading (AUC, 0.898; P < .001) were significantly associated with GAE outcome. To predict GAE responders, KL grade ≤ 2 yielded a sensitivity of 87.5% and a specificity of 60.9%, BML grade ≤ 1 yielded a sensitivity of 75.0% and a specificity of 69.6%, and meniscal injury grade ≤ 2 yielded a sensitivity of 83.3% and a specificity of 72.7%.

CONCLUSIONS

Large BMLs and severe meniscal injuries on MR imaging, as well as high KL grades, indicated poor responses to GAE.

Discovery and preclinical efficacy of HSG4112, a synthetic structural analog of glabridin, for the treatment of obesity

Background

HSG4112 is a clinical-stage drug candidate for the treatment of obesity. Here, we report its discovery and preclinical efficacy.

Methods

In high-fat diet (HFD)-induced obese male C57BL/6J mice, we tested the weight loss effect of synthetic compounds derived from a structure–activity relationship (SAR) study of glabridin, a natural compound known to reduce body weight and influence energy homeostasis. After selecting HSG4112 as our optimized compound from this discovery method, we characterized its pharmacological effects on parameters related to obesity through in vivo metabolic and biochemical measurements, histology and gene expression analysis, and indirect calorimetry.

Results

Through the SAR study, we identified four novel components of glabridin pertinent for its anti-obesity activity, and found that HSG4112, an optimized structural analog of glabridin, markedly supersedes glabridin in weight reduction efficacy and chemical stability. Six-week administration of HSG4112 to HFD-induced obese mice led to dose-dependent normalization of obesity-related parameters, including body weight, muscle and adipose tissue weight, adipocyte size, and serum leptin/insulin/glucose levels. The weight reduction induced by HSG4112 was partially mediated by decreased food intake and mainly mediated by increased energy expenditure, with no change in physical activity. Accordingly, the pattern of transcriptional changes was aligned with increased energy expenditure in the liver and muscles. Following significant body weight reduction, robust amelioration of histopathology and blood markers of fatty liver were also observed.

Conclusions

Our study demonstrates the key chemical components of glabridin pertinent to its weight loss effects and suggests HSG4112 as a promising novel drug candidate for the pharmacological treatment of obesity.

Aberrant gastric venous drainage and associated atrophy of hepatic segment II: computed tomography analysis of 2021 patients

PURPOSE

To investigate the prevalence and patterns of aberrant gastric venous drainage and associated atrophy of the hepatic segment on contrast-enhanced computed tomography (CT).

METHODS

Two radiologists retrospectively reviewed contrast-enhanced CT images from 2021 patients who underwent cone-beam CT-guided chemoembolization between January 2013 and December 2018. They determined the presence or absence of an aberrant gastric vein(s) and its drainage site by consensus, and qualitatively analyzed the presence or absence of atrophy of segments II or III. In cases of disagreement between the two reviewers regarding the presence of atrophy, quantitative analysis was performed using dedicated software.

RESULTS

A total of 31 aberrant right gastric veins were revealed on CT (1.5%), most of which drained into P2 (n = 8), the S2/3 border zone (n = 8), S2 (n = 6), or S4 (n = 5). An aberrant left gastric vein was observed in 21 (1.0%) patients, and P2 was the most common drainage site (n = 13) in these patients. Atrophy of segment II was more frequently observed among patients with aberrant gastric veins than among those without (26.9% versus 4.1%; p < 0.001). In addition, an aberrant gastric vein draining into P2 was most frequently accompanied by segment II atrophy (47.6%).

CONCLUSION

Aberrant right and left gastric veins were observed in 1.5% and 1.0% of patients, respectively. Atrophy of segment II was frequently observed in patients with aberrant gastric veins, especially those that drained into P2.

Glue Embolization of Lymphopseudoaneurysm for Chylous Ascites after Retroperitoneal Surgery

OBJECTIVE

To assess the safety and efficacy of lymphopseudoaneurysm (LPA) glue (n-butyl cyanoacrylate [NBCA]) embolization in the management of chylous ascites after retroperitoneal surgery.

MATERIALS AND METHODS

A retrospective analysis from January 2014 to October 2018 was performed in six patients (4 females and 2 males; mean age, 45.3 ± 14.2 years; range, 26-61 years) who underwent LPA embolization for chylous ascites developing after retroperitoneal surgery involving the perirenal space (four donor nephrectomies, one partial nephrectomy, and one retroperitoneal lymphadenectomy). After placing a percutaneous drainage catheter into the LPA or adjacent lymphocele, embolization was performed by filling the LPA itself with a mixture of glue and Lipiodol (Guerbet).

RESULTS

Daily drainage from percutaneously placed drains exceeded 300 mL/day despite medical and surgical treatment (volume: mean, 1173 ± 1098 mL; range, 305-2800 mL). Intranodal lymphangiography was performed in four of the six patients and revealed leakage in 2 patients. Percutaneous embolization of the LPA was successful in all patients using an NBCA and Lipiodol mixture in a ratio of 1:1-1:2 (volume: mean, 4.3 ± 1.1 mL; range, 3-6 mL). Chylous ascites was resolved and the drainage catheter was removed in all patients within 4 days after the procedure (mean, 2.0 ± 1.8 days; range, 0-4 days). No procedure-related complications or recurrence of chylous ascites occurred during a mean follow-up period of 37.3 months (range, 21.1-48.4 months).

CONCLUSION

Glue embolization of LPA has the potential to be a feasible and effective treatment method for the management of chylous ascites after retroperitoneal surgery.

Shaping the tip of microcatheters for superselective catheterization: steam vs. manual methods

PURPOSE

We aimed to evaluate and compare the shapeability and stability of five microcatheters commonly used in interventional radiology after steam shaping and manual shaping.

METHODS

Steam shaping was performed using three mandrels of different angles: L(S) shape (90°), U(S) shape (180°), and O(S) shape (360°). Three manual shapes-L(M), U(M), and O(M)-were made to have a similar angle to their steam-shaped counterparts. The stability of the microcatheters was evaluated by passing them through a 5 F catheter and inserting microguidewires. The tip angles of the microcatheters and the angle change rates were compared between groups.

RESULTS

The mean angle of the microcatheters after steam shaping was 42.4°-54.1° for L(S) shape, 80.2°-96.7° for U(S) shape, and 130.7°-150.8° for O(S) shape. Five microcatheters showed significantly different mean angle reductions after passing through the 5 F catheter (17.4%-30.3%) and inserting microguidewires (24.1%-61.2%). Different microguidewires also caused significantly different mean angle reductions (34.6%-50.8%). The reduced angle caused by the guidewire was almost completely recovered after withdrawing it (93.2%-101.6%). Although manual-shaped microcatheters showed a 4.2%-6.3% greater angle reduction than steam-shaped microcatheters after passing through the 5 F catheter, the final tip angle was not significantly different between the two groups and was within 10%.

CONCLUSION

The tip angle of the microcatheters after steam shaping using mandrels may differ depending on the shape of the mandrel and the type of microcatheter used, and the stability varies depending on the type of microcatheter. The manual shaping of microcatheters can be a good alternative to steam shaping.

How to Best Detect Portal Vein Tumor Thrombosis in Patients with Hepatocellular Carcinoma Meeting the Milan Criteria: Gadoxetic Acid-Enhanced MRI versus Contrast-Enhanced CT

INTRODUCTION

The detection of portal vein tumor thrombosis (PVTT) in patients with hepatocellular carcinoma (HCC) meeting the Milan criteria is of critical importance as PVTT is known to be a contraindication to transplantation and an indicator of a dismal prognosis.

OBJECTIVE

To determine which modality may best detect PVTT, we compared the diagnostic performance of gadoxetic acid-enhanced MRI (GA-MRI) and contrast-enhanced CT (CECT) in HCC patients meeting the Milan criteria.

METHODS

We retrospectively enrolled 310 patients with HCCs meeting the Milan criteria who underwent both GA-MRI and CECT between June 2007 and May 2017. Among them, 44 patients were demonstrated to have PVTT while 266 patients had no PVTT. Two radiologists then assessed GA-MRI and CECT images for the presence of PVTT on a 5-point scale as well as vessel expansion, continuity with tumors, and enhancement on both modalities, as well as T2 hyperintensity and diffusion restriction on GA-MRI. The McNemar test was used to compare sensitivity and specificity of GA-MRI and CECT for the detection of PVTT, and Fisher's exact test was used to compare their imaging features.

RESULTS

GA-MRI showed higher sensitivity values than CECT in detecting PVTT (reviewer 1, 93.2% [41/44] vs. 77.3% [34/44]; reviewer 2, 88.6% [39/44] vs. 70.5% [31/44]) (both p = 0.039). Specificity of GA-MRI and CECT demonstrated no difference (reviewer 1, 95.5% [254/266] vs. 95.1% [253/266]; reviewer 2, 97.0% [258/266] vs. 97.4% [259/266]) (both p > 0.999). Continuity with tumors and enhancement were more frequently observed on GA-MRI than on CECT (p < 0.050, both reviewers).

CONCLUSION

GA-MRI detected PVTT more often than CECT in HCC patients meeting the Milan criteria and better depicted PVTT in continuity with tumors and those showing enhancement than CECT.

A differential risk assessment and decision model for Transarterial chemoembolization in hepatocellular carcinoma based on hepatic function

Background

The decision of transarterial chemoembolization (TACE) initiation and/or repetition remains challenging in patients with unresectable hepatocellular carcinoma (HCC). The aim was to develop a prognostic scoring system to guide TACE initiation/repetition.

Methods

A total of 597 consecutive patients who underwent TACE as their initial treatment for unresectable HCC were included. We derived a prediction model using independent risk factors for overall survival (OS), which was externally validated in an independent cohort (n = 739).

Results

Independent risk factors of OS included Albumin-bilirubin (ALBI) grade, maximal tumor size, alpha-fetoprotein, and tumor response to initial TACE, which were used to develop a scoring system (“ASAR”). C-index values for OS were 0.733 (95% confidence interval [CI] = 0.570–0.871) in the derivation, 0.700 (95% CI = 0.445–0.905) in the internal validation, and 0.680 (95% CI = 0.652–0.707) in the external validation, respectively. Patients with ASAR< 4 showed significantly longer OS than patients with ASAR≥4 in all three datasets (all P < 0.001). Among Child-Pugh class B patients, a modified model without TACE response, i.e., “ASA(R)”, discriminated OS with a c-index of 0.788 (95% CI, 0.703–0.876) in the derivation, and 0.745 (95% CI, 0.646–0.862) in the internal validation, and 0.670 (95% CI, 0.605–0.725) in the external validation, respectively. Child-Pugh B patients with ASA(R) < 4 showed significantly longer OS than patients with ASA(R) ≥ 4 in all three datasets (all P < 0.001).

Conclusions

ASAR provides refined prognostication for repetition of TACE in patients with unresectable HCC. For Child-Pugh class B patients, a modified model with baseline factors might guide TACE initiation.

Transcatheter arterial embolization for advanced gastric cancer bleeding: A single-center experience with 58 patients

To investigate computed tomography and angiography findings and clinical outcomes after transcatheter arterial embolization for acute upper gastrointestinal bleeding from advanced gastric cancers.From January 2005 to December 2014, 58 patients with pathologically proven gastric cancer were treated at our institution with transcatheter arterial embolization due to acute upper gastrointestinal bleeding recalcitrant to endoscopic treatment. The electronic medical records for each patient were reviewed for clinical presentation, endoscopy history, computed tomography and angiographic findings, blood transfusion requirements, and follow-up results.Angiography findings were positive in 13 patients (22.4%): contrast extravasation was found in 9 patients and pseudoaneurysm in 4 patients. All patients with positive angiograms underwent selective embolization treatment. Those with negative angiography findings underwent empirical embolization. Gelfoam, n-butyl cyanoacrylate, coils, or a combination of these were used as embolic agents. The overall clinical success rate was 72.4% (42/58), and the success rate for patients with positive angiography was 53.8% (7/13). The median survival was 97.5 days (range, 7-1415 days), and the 1-month survival rate was 89.6% (52/58). The 1-month survival rate of the clinical success group was 95.2% (40/42), which was significantly higher than that of the clinical failure group (P = .04). The clinical success group also required significantly fewer transfusions (2.43 units, range 0-24 units) (P = .02).Transcatheter arterial embolization is a highly effective treatment for advanced gastric cancer with active bleeding. It should be considered as an additional treatment, especially when endoscopic or surgical treatment fails or when these approaches are difficult.

Iatrogenic Arterioportal Fistula Caused by Radiofrequency Ablation of Hepatocellular Carcinoma: Clinical Course and Treatment Outcomes

PURPOSE

To analyze the clinical course and treatment outcomes of patients with iatrogenic arterioportal fistula (APF) caused by radiofrequency (RF) ablation of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Among the 1,620 hepatocellular carcinoma patients treated by RF ablation between January 2012 and August 2017, 99 who developed APF after RF ablation were included in this retrospective study. Depending on the extent of portal vein enhancement on arterial phase images, APF was classified as massive or nonmassive. The patients' clinical course was investigated and statistically evaluated by univariable and multivariable analyses.

RESULTS

Thrombocytopenia (odds ratio [OR] = 3.939; 95% confidence interval [CI], 1.141-13.598) was the only risk factor for developing massive APF. Eleven patients underwent embolotherapy (technical success rate, 90.9%) and no patients experienced serious adverse events within 30 days of the procedure. Patients with massive APF (66.7%) had a significantly higher chance of a Child-Pugh score increase than did the patients with nonmassive APF (13.6%) (P < .001). Massive APF had a significantly lower chance of natural regression than did nonmassive APF (P < .001). Child-Pugh B (OR = 17.739; 95% confidence interval, 2.361-133.279) and massive APF without treatment (OR = 11.061; 95% confidence interval, 1.257-97.341) were independent risk factors for liver failure that led to death of liver transplant within 1 year after RF ablation.

CONCLUSIONS

Massive APF caused by RF ablation is mostly irreversible and significantly worsens patients' outcomes, but may be effectively treated with embolotherapy.

Selective Chemoembolization of Caudate Lobe Hepatocellular Carcinoma: Anatomy and Procedural Techniques

Transarterial chemoembolization is the most common treatment for unresectable hepatocellular carcinomas (HCCs). However, when an HCC is located in the caudate lobe, many interventional radiologists are reluctant to perform chemoembolization and percutaneous ablation owing to the tumor's complex vascular supply and deep location. With the advent of C-arm CT, rendering the three-dimensional display of the hepatic artery and detecting the tumor-feeding vessels are possible and can help guide interventional radiologists to the tumor. The common origins of the caudate artery include the right hepatic artery, left hepatic artery, right anterior hepatic artery, and right posterior hepatic artery. The origins of the tumor-feeding arteries of a caudate lobe HCC can vary depending on the tumor's subsegmental location. Caudate lobe HCCs are commonly fed by multiple caudate arteries that are connected. In addition, extrahepatic collateral arteries frequently supply recurrent tumors in the caudate lobe. The caudate artery can supply portal vein thrombi or biliary tumor thrombi in patients with HCC. Several techniques such as preshaping the microcatheter or using the shepherd's hook technique are needed to catheterize the caudate artery in complex cases. Although uncommon, bile duct stricture is a serious complication following selective chemoembolization through the caudate artery. Identification and catheterization of the caudate artery have become possible in most patients by using C-arm CT and a fine microcatheter system, respectively. The authors review the anatomy of the caudate artery with C-arm CT and describe basic technical considerations in selective chemoembolization for caudate lobe HCCs. Unusual circumstances that require catheterization and techniques used for catheterizing the caudate artery are also described. Online supplemental material is available for this article. ^©RSNA, 2019.