Comparison of Clinical Outcomes Using Left and Right Liver Grafts in Adult-to-adult Living-donor Liver Transplantation: A Retrospective Cohort Study Using the Korean Organ Transplantation Registry.

BACKGROUND: Living-donor liver transplantation has been widely performed as an alternative to the scarce liver grafts from deceased donors. More studies are reporting favorable outcomes of left liver graft (LLG). This study compared the clinical outcomes between living-donor liver transplantation using LLG and right liver graft (RLG) with similar graft-to-recipient body weight ratios. METHODS: This study analyzed 4601 patients from a multicenter observational cohort using the Korean Organ Transplantation Registry between 2014 and 2021. After matching the Model for End-stage Liver Disease score and graft-to-recipient body weight ratios because of the extremely different number in each group, the LLG and RLG groups comprised 142 (25.1%) and 423 (74.9%) patients, respectively. RESULTS: For donors, the median age was higher in the LLG group than in the RLG group (34 y [range, 16-62 y] versus 30 y [16-66 y] ; P = 0.002). For recipients, the LLG group showed higher 90-d mortality than the RLG group (11 [7.7%] versus 9 [2.1%]; P = 0.004). The long-term graft survival was significantly worse in the LLG group (P = 0.011). In multivariate Cox proportional hazards regression analysis for graft survival, LLG was not a significant risk factor (hazard ratio, 1.01 [0.54-1.87]; P = 0.980). Otherwise, donor age (≥40 y; 2.18 y [1.35-3.52 y]; P = 0.001) and recipients' body mass index (<18.5 kg/m2; 2.98 kg/m2 [1.52-5.84 kg/m2]; P = 0.002) were independent risk factors for graft survival. CONCLUSIONS: Although the short-term and long-term graft survival was worse in the LLG group, LLG was not an independent risk factor for graft survival in multivariate analysis. LLGs are still worth considering for selected donors and recipients regarding risk factors for graft survival.

Impact of Baseline Anti-ABO Antibody Titer on Biliary Complications in ABO-Incompatible Living-Donor Liver Transplantation.

Background: Although advancements in desensitization protocols have led to increased ABO-incompatible (ABOi) living-donor liver transplantation (LDLT), a higher biliary complication rate remains a problem. This study evaluated the effect of baseline anti-ABO antibody titers before desensitization on biliary complications after ABOi LDLT. Methods: The study cohort comprised 116 patients in the ABO-compatible group (ABOc), 29 in the ABOi with the low titer (<1:128) group (ABOi-L), and 14 in the high titer (≥1:128) group (ABOi-H). Results: Biliary complications occurred more frequently in the ABOi-H group than in the ABOi-L and ABOc groups (7 [50.0%] vs. 8 [27.6%] and 24 [20.7%], respectively, p = 0.041). Biliary complication-free survival was significantly worse in the ABOi-H group than in the other groups (p = 0.043). Diffuse intrahepatic biliary strictures occurred more frequently in the ABOi-H group than in the other groups (p = 0.005). Multivariable analysis revealed that the high anti-ABO antibody titer (≥1:128) is an independent risk factor for biliary complications (hazard ratio 3.943 [1.635-9.506]; p = 0.002). Conclusions: A high baseline anti-ABO antibody titer (≥1:128), female sex, and hepatic artery complications are significant risk factors for biliary complications.

Novel role of MHC class II transactivator in hepatitis B virus replication and viral counteraction.

BACKGROUND/AIMS: The major histocompatibility class II (MHC II) transactivator, known as CIITA, is induced by Interferon gamma (IFN-γ) and plays a well-established role in regulating the expression of class II MHC molecules in antigen-presenting cells. METHODS: Primary human hepatocytes (PHH) were isolated via therapeutic hepatectomy from two donors. The hepatocellular carcinoma (HCC) cell lines HepG2 and Huh7 were used for the mechanistic study, and HBV infection was performed in HepG2-NTCP cells. HBV DNA replication intermediates and secreted antigen levels were measured using Southern blotting and ELISA, respectively. RESULTS: We identified a non-canonical function of CIITA in the inhibition of hepatitis B virus (HBV) replication in both HCC cells and patient-derived PHH. Notably, in vivo experiments demonstrated that HBV DNA and secreted antigen levels were significantly decreased in mice injected with the CIITA construct. Mechanistically, CIITA inhibited HBV transcription and replication by suppressing the activity of HBV-specific enhancers/promoters. Indeed, CIITA exerts antiviral activity in hepatocytes through ERK1/2-mediated down-regulation of the expression of hepatocyte nuclear factor 1α (HNF1α) and HNF4α, which are essential factors for virus replication. In addition, silencing of CIITA significantly abolished the IFN-γ-mediated anti-HBV activity, suggesting that CIITA mediates the anti-HBV activity of IFN-γ to some extent. HBV X protein (HBx) counteracts the antiviral activity of CIITA via direct binding and impairing its function. CONCLUSION: Our findings reveal a novel antiviral mechanism of CIITA that involves the modulation of the ERK pathway to restrict HBV transcription. Additionally, our results suggest the possibility of a new immune avoidance mechanism involving HBx.

Surgical outcome and risk scoring to predict survival after hepatic resection for hepatocellular carcinoma with portal vein tumor thrombosis.

Backgrounds/Aims: The hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is classified as the advanced stage (BCLC stage C) with extremely poor prognosis, and in current guidelines is recommended for systemic therapy. This study aimed to evaluate the surgical outcomes and long-term prognosis after hepatic resection (HR) for patients who have HCC combined with PVTT. Methods: We retrospectively analyzed 332 patients who underwent HR for HCC with PVTT at ten tertiary referral hospitals in South Korea. Results: The median overall and recurrence-free survival after HR were 32.4 and 8.6 months, while the 1-, 3-, and 5-year overall survival rates were 75%, 48%, and 39%, respectively. In multivariate analysis, tumor number, tumor size, AFP, PIVKA-II, neutrophil-to-lymphocyte ratio, and albumin-bilirubin (ALBI) grade were significant prognostic factors. The risk scoring was developed using these seven factors-tumor, inflammation and hepatic function (TIF), to predict patient prognosis. The prognosis of the patients was well stratified according to the scores (log-rank test, p < 0.001). Conclusions: HR for patients who have HCC combined with PVTT provided favorable survival outcomes. The risk scoring was useful in predicting prognosis, and determining the appropriate treatment strategy for those patients who have HCC with PVTT.

Small graft size and hepatocellular carcinoma outcomes in living donor liver transplantation: a retrospective multicentric cohort study.

INTRODUCTION: This study examined associations between the graft-to-recipient weight ratio (GRWR) for adult-to-adult living donor liver transplantation (LDLT) and hepatocellular carcinoma (HCC) outcomes. MATERIALS AND METHODS: Data from patients in the Korean Organ Transplantation Registry who underwent LDLT for HCC from 2014 to 2021 were retrospectively reviewed. Patients were categorized using the cutoff GRWR for HCC recurrence determined by an adjusted cubic spline (GRWR <0.7% vs. GRWR ≥0.7%). Recurrence-free survival (RFS) and HCC recurrence were analyzed in the entire and a 1:5 propensity-matched cohort. RESULTS: The eligible cohort consisted of 2005 LDLT recipients [GRWR <0.7 ( n =59) vs. GRWR ≥0.7 ( n =1946)]. In the entire cohort, 5-year RFS was significantly lower in the GRWR <0.7 than in the GRWR ≥0.7 group (66.7% vs. 76.7%, P =0.019), although HCC recurrence was not different between groups (77.1% vs. 80.7%, P =0.234). This trend was similar in the matched cohort ( P =0.014 for RFS and P =0.096 for HCC recurrence). In multivariable analyses, GRWR <0.7 was an independent risk factor for RFS [adjusted hazard ratio (aHR) 1.89, P =0.012], but the result was marginal for HCC recurrence (aHR 1.61, P =0.066). In the pretransplant tumor burden subgroup analysis, GRWR <0.7 was a significant risk factor for both RFS and HCC recurrence only for tumors exceeding the Milan criteria (aHR 3.10, P <0.001 for RFS; aHR 2.92, P =0.003 for HCC recurrence) or with MoRAL scores in the fourth quartile (aHR 3.33, P <0.001 for RFS; aHR 2.61, P =0.019 for HCC recurrence). CONCLUSIONS: A GRWR <0.7 potentially leads to lower RFS and higher HCC recurrence after LDLT when the pretransplant tumor burden is high.

Tripartite motif-containing protein 21 is involved in IFN-γ-induced suppression of hepatitis B virus by regulating hepatocyte nuclear factors.

The antiviral role of the tripartite motif-containing (TRIM) protein family , a member of the E3-ubiquitin ligase family, has recently been actively studied. Hepatitis B virus (HBV) infection is a major contributor to liver diseases; however, the host factors regulated by cytokine-inducible TRIM21 to suppress HBV remain unclear. In this study, we showed the antiviral efficacy of TRIM21 against HBV in hepatoma cell lines, primary human hepatocytes isolated from patient liver tissues, and mouse model. Using TRIM21 knock-out cells, we confirmed that the antiviral effects of interferon-gamma, which suppress HBV replication, are diminished when TRIM21 is deficient. Northern blot analysis confirmed a reduction of HBV RNA levels by TRIM21. Using Luciferase reporter assay, we also discovered that TRIM21 decreases the activity of HBV enhancers, which play a crucial role in covalently closed circular DNA transcription. The participation of the RING domain and PRY-SPRY domain in the anti-HBV effect of TRIM21 was demonstrated through experiments using deletion mutants. We identified a novel interaction between TRIM21 and hepatocyte nuclear factor 4α (HNF4α) through co-immunoprecipitation assay. More specifically, ubiquitination assay revealed that TRIM21 promotes ubiquitin-mediated proteasomal degradation of HNF4α. HNF1α transcription is down-regulated as a result of the degradation of HNF4α, an activator for the HNF1α promoter. Therefore, the reduction of key HBV enhancer activators, HNF4α and HNF1α, by TRIM21 resulted in a decline in HBV transcription, ultimately leading to the inhibition of HBV replication.IMPORTANCEDespite extensive research efforts, a definitive cure for chronic hepatitis B remains elusive, emphasizing the persistent importance of this viral infection as a substantial public health concern. Although the risks associated with hepatitis B virus (HBV) infection are well known, host factors capable of suppressing HBV are largely uncharacterized. This study elucidates that tripartite motif-containing protein 21 (TRIM21) suppresses HBV transcription and consequently inhibits HBV replication by downregulating the hepatocyte nuclear factors, which are host factors associated with the HBV enhancers. Our findings demonstrate a novel anti-HBV mechanism of TRIM21 in interferon-gamma-induced anti-HBV activity. These findings may contribute to new strategies to block HBV.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation.

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Measurements of the noise power spectrum for digital x-ray imaging devices.

Objective.The noise characteristics of digital x-ray imaging devices are determined by contributions such as photon noise, electronic noise, and fixed pattern noise, and can be evaluated from measuring the noise power spectrum (NPS), which is the power spectral density of the noise. Hence, accurately measuring NPS is important in developing detectors for acquiring low-noise digital x-ray images. To make accurate measurements, it is necessary to understand NPS, identify problems that may arise, and know how to process the obtained x-ray images.Approach.The primitive concept of NPS is first introduced with a periodogram-based estimate and its bias and variance are discussed. In measuring NPS based on the IEC62220 standards, various issues, such as the fixed pattern noise, high-precision estimates, and lag corrections, are summarized with simulation examples.Main results.High-precision estimates can be provided for an appropriate number of samples extracted from x-ray images while compromising spectral resolution. Depending on medical imaging systems, by eliminating the influence of fixed pattern noise, NPS, which represents only photon and electronic noise, can be efficiently measured. For NPS measurements in dynamic detectors, an appropriate lag correction technique can be selected depending on the emitted x-rays and image acquisition process.Significance.Various issues in measuring NPS are reviewed and summarized for accurately evaluating the noise performance of digital x-ray imaging devices.

The effect of donor against recipient one-way HLA mismatch on liver transplantation outcomes from a multicenter registry analysis.

Donor against recipient one-way Human leukocyte antigen (HLA) mismatch (D → R one-way HLA MM) seemed strongly associated with graft-versus-host disease (GVHD). The aim of this study is to investigate the relevance of D → R one-way HLA MM in outcome of liver transplantation (LT). We retrospectively analyzed 2670 patients in Korean Organ Transplantation Registry database between April 2014 and December 2020. The patients were categorized into two groups whether D → R one-way HLA MM or not and evaluated the outcomes of LT between the two groups. 18 patients were found to be D → R one-way HLA MM. The incidence of GVHD (0.3% vs. 22.2%, p < 0.001) and mortality rate (11.6% vs. 38.9%, p = 0.003) was much higher in D → R one-way HLA MM group. D → R one-way HLA MM at 3 loci was seemed to be strongly associated with the incidence of GVHD (OR 163.3, p < 0.001), and found to be the strongest risk factor for patient death (HR 12.75, p < 0.001). Patients with D → R one-way HLA MM at 3 loci showed significantly lower overall survival (p < 0.001) but there were no significant differences in rejection-free survival and death-censored graft survival. D → R one-way HLA MM at 3 loci not only affects the overall survival of LT patients but also the incidence of GVHD.

Impact of preoperative red blood cell transfusion on long-term mortality of liver transplantation: A retrospective cohort study.

Preoperative red blood cell (RBC) transfusion can induce immune modulation and alloimmunization; however, few studies have investigated the effect of preoperative transfusion and hemoglobin levels that need to be corrected before surgery, especially in critically ill patients such as those with end-stage liver disease who undergo liver transplantation (LT). This study aimed to investigate the effects of preoperative RBC transfusion on long-term mortality in LT recipients. A total of 249 patients who underwent LT at a single center between January 2012 and December 2021 were included in this study. The patients were divided into 2 groups: preoperative transfusion and preoperative non-transfusion. Since the baseline characteristics were significantly different between the 2 groups, we performed propensity score matching, including factors such as the Model for End-Stage Liver Disease score and intraoperative RBC transfusion, to exclude possible biases that could affect prognosis. We analyzed the 5-year mortality rate as the primary outcome. The preoperative transfusion group showed a 4.84-fold higher hazard ratio than that in the preoperative non-transfusion group. There were no differences in 30-day mortality, duration of intensive care unit stay, or graft rejection rate between the 2 groups. Preoperative transfusion could influence long-term mortality in LT, and clinicians should pay attention to RBC transfusion before LT unless the patient is hemodynamically unstable. A large-scale randomized controlled trial is needed to determine the possible mechanisms related to preoperative RBC transfusion, long-term mortality, and the level of anemia that should be corrected before surgery.

Clinical outcome of surgical resection for multifocal T2-T3 hepatocellular carcinoma up to 3 nodules: a comparative analysis with a single nodule.

BACKGROUND/AIMS: Although the Barcelona Clinic Liver Cancer staging system seems to underestimate the impact of curative-intent surgical resection for multifocal hepatocellular carcinoma (HCC), recent studies have indicated favorable results for the surgical resection of multiple HCC. This study aimed to assess clinical outcomes and feasibility of surgical resection for multifocal HCC with up to three nodules compared with single tumor cases. METHODS: Patients who underwent surgical resection for HCC with up to three nodules between 2009 and 2020 were included, and those with the American Joint Committee on Cancer (AJCC) 8th edition, T1 and T4 stages were excluded to reduce differences in disease distribution and severity. Finally, 81 and 52 patients were included in the single and multiple treatment groups, respectively. Short- and long-term outcomes including recurrence-free survival (RFS) and overall survival (OS), were evaluated. RESULTS: All patients were classified as Child-Pugh class A. RFS and OS were not significantly different between the two groups (P=0.176 and P=0.966, respectively). Multivariate analysis revealed that transfusion and intrahepatic metastasis were significantly associated with recurrence (P=0.046 and P=0.005, respectively). Additionally, intrahepatic metastasis was significantly associated with OS (hazard ratio, 1.989; 95% confidence interval, 1.040-3.802; P=0.038). CONCLUSIONS: Since there was no significant difference in survival between the single and multiple groups among patients with AJCC 8th stage T2 and T3, surgical resection with curative intent could be considered with acceptable long-term survival for selected patients with multiple HCC of up to three nodules.

Outcomes and Risk Factors for Liver Transplantation Using graft-to-Recipient Weight Ratio Less than 0.8 Graft from Living Donors: Multicentric Cohort Study.

OBJECTIVE: To compare graft survival after LDLT in patients receiving GRWR<0.8 versus GRWR≥0.8 grafts and identify risk factors for graft loss using GRWR<0.8 grafts. SUMMARY BACKGROUND DATA: Favorable outcomes after living donor liver transplantation (LDLT) using graft-to-recipient weight ratio (GRWR)<0.8 grafts were recently reported; however, these results have not been validated using multicenter data. METHODS: This multicentric cohort study included 3450 LDLT patients. Graft survival was compared between 1:3 propensity score-matched groups and evaluated using various Cox models in the entire population. Risk factors for graft loss with GRWR<0.8 versus GRWR≥0.8 grafts were explored within various subgroups using interaction analyses, and outcomes were stratified according to the number of risk factors. RESULTS: In total, 368 patients (10.7%) received GRWR<0.8 grafts (GRWR<0.8 group), whereas 3082 (89.3%) received GRWR≥0.8 grafts (GRWR≥0.8 group). The 5-y graft survival rate was significantly lower with GRWR<0.8 grafts than with GRWR≥0.8 grafts (85.2% vs. 90.1%, P=0.013). Adjusted hazard ratio (HR) for graft loss using GRWR<0.8 grafts in the entire population was 1.66 (95% confidence interval [CI] 1.17-2.35, P=0.004). Risk factors exhibiting significant interactions with GRWR<0.8 for graft survival were age ≥60 y, MELD score ≥15, and male donor. When ≥2 risk factors were present, GRWR<0.8 grafts showed higher risk of graft loss compared to GRWR≥0.8 graft in LDLT (HR 2.98, 95% CI 1.79-4.88, P<0.001). CONCLUSIONS: GRWR<0.8 graft showed inferior graft survival than controls (85.2% vs. 90.1%), especially when ≥2 risk factors for graft loss (among age ≥60 y, MELD score ≥15, or male donor) were present.

Post Living Donor Liver Transplantation Small-for-size Syndrome: Definitions, Timelines, Biochemical, and Clinical Factors for Diagnosis: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference.

BACKGROUND: When a partial liver graft is unable to meet the demands of the recipient, a clinical phenomenon, small-for-size syndrome (SFSS), may ensue. Clear definition, diagnosis, and management are needed to optimize transplant outcomes. METHODS: A Consensus Scientific committee (106 members from 21 countries) performed an extensive literature review on specific aspects of SFSS, recommendations underwent blinded review by an independent panel, and discussion/voting on the recommendations occurred at the Consensus Conference. RESULTS: The ideal graft-to-recipient weight ratio of ≥0.8% (or graft volume standard liver volume ratio of ≥40%) is recommended. It is also recommended to measure portal pressure or portal blood flow during living donor liver transplantation and maintain a postreperfusion portal pressure of <15 mm Hg and/or portal blood flow of <250 mL/min/100 g graft weight to optimize outcomes. The typical time point to diagnose SFSS is the postoperative day 7 to facilitate treatment and intervention. An objective 3-grade stratification of severity for protocolized management of SFSS is proposed. CONCLUSIONS: The proposed grading system based on clinical and biochemical factors will help clinicians in the early identification of patients at risk of developing SFSS and institute timely therapeutic measures. The validity of this newly created grading system should be evaluated in future prospective studies.

Liver transplantation for combined hepatocellular carcinoma and cholangiocarcinoma: A multicenter study.

BACKGROUND: Patients with combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) are not traditionally considered eligible for liver transplantation (LT) due to poor outcomes. AIM: To compare outcomes between living donor LT (LDLT) patients with hepatocellular carcinoma (HCC) and LT patients with cHCC-CC and to identify risk factors for tumor recurrence and death after LT in cHCC-CC patients. METHODS: Data for pathologically diagnosed cHCC-CC patients (n = 111) who underwent LT from 2000 to 2018 were collected for a nine-center retrospective review. Patients (n = 141) who received LDLT for HCC at Samsung Medical Center from January 2013 to March 2017 were selected as the control group. Seventy patients in two groups, respectively, were selected by 1:1 matching. RESULTS: Cumulative disease-free survival (DFS) and overall survival (OS) in the cHCC-CC group were significantly worse than in the HCC group both before and after matching. Extrahepatic recurrence incidence in the cHCC-CC group was higher than that in the HCC group (75.5% vs 33.3%, P < 0.001). Multivariate analysis demonstrated that the cHCC-CC group had significantly higher rates of tumor recurrence and death compared to the HCC group. In cHCC-CC subgroup analysis, frequency of locoregional therapies > 3, tumor size > 3 cm, and lymph node metastasis were predisposing factors for tumor recurrence in multivariate analysis. Only a maximum tumor size > 3 cm was a predisposing factor for death. CONCLUSION: The poor prognosis of patients diagnosed with cHCC-CC after LT can be predicted based on the explanted liver. Frequent regular surveillance for cHCC-CC patients should be required for early detection of tumor recurrence.

Entecavir versus tenofovir on the recurrence of hepatitis B-related HCC after liver transplantation: A multicenter observational study.

Considerable controversy exists regarding the superiority of tenofovir disoproxil fumarate (TDF) over entecavir (ETV) for reducing the risk of HCC. This study aimed to compare outcomes of ETV versus TDF after liver transplantation (LT) in patients with HBV-related HCC. We performed a multicenter observational study using data from the Korean Organ Transplantation Registry. A total of 845 patients who underwent LT for HBV-related HCC were divided into 2 groups according to oral nucleos(t)ide analogue used for HBV prophylaxis post-LT: ETV group (n = 393) and TDF group (n = 452). HCC recurrence and overall death were compared in naïve and propensity score (PS)-weighted populations, and the likelihood of these outcomes according to the use of ETV or TDF were analyzed with various Cox models. At 1, 3, and 5 years, the ETV and TDF groups had similar HCC recurrence-free survival (90.7%, 85.6%, and 84.1% vs. 90.9%, 84.6%, and 84.2%, respectively, p = 0.98) and overall survival (98.4%, 94.7%, and 93.5% vs. 99.3%, 95.8%, and 94.9%, respectively, p = 0.48). The propensity score-weighted population showed similar results. In Cox models involving covariates adjustment, propensity score-weighting, competing risk regression, and time-dependent covariates adjustment, both groups showed a similar risk of HCC recurrence and overall death. In subgroup analyses stratified according to HCC burden (Milan criteria, Up-to-7 criteria, French alpha-fetoprotein risk score), pretransplantation locoregional therapy, and salvage LT, neither ETV nor TDF was superior. In conclusion, ETV and TDF showed mutual noninferiority for HCC outcomes when used for HBV prophylaxis after LT.

A single-center experience of over 300 cases of single-incision robotic cholecystectomy comparing the da Vinci SP with the Si/Xi systems.

Minimally invasive surgery is usually more beneficial than open surgeries in various fields of surgery. With the newly developed Single-Port (SP) robotic surgical system, even single-site surgery has become easier to access. We compared single-incision robotic cholecystectomy between the Si/Xi and SP systems. This retrospective single-center study enrolled patients who underwent single-incision robotic cholecystectomy between July 2014 and July 2021. The clinical outcomes of the da Vinci Si/Xi and SP systems were compared. In total, 334 patients underwent single-incision robotic cholecystectomy (118 Si/Xi vs. 216 SP). The SP group had more chronic or acute cholecystitis than the Si/Xi group did. There was more bile spillage in the Si/Xi group during the surgery. The total operative and docking times were significantly shorter in the SP group. There was no difference in the postoperative outcomes. The SP system is safe and feasible regarding comparable postoperative complication rates and is more convenient regarding docking and techniques.

Quantitative Prediction of Posttransplant Hepatocellular Carcinoma Prognosis Using ADV Score: Validation with Korea-Nationwide Transplantation Registry Database.

OBJECTIVE: The aim of this study is to validate the prognostic impact of ADV score (α-fetoprotein [AFP]-des-γ-carboxyprothrombin [DCP]-tumor volume [TV] score) for predicting prognosis of hepatocellular carcinoma (HCC) following liver transplantation (LT). BACKGROUND: ADV score has been reported as a prognostic surrogate biomarker of HCC following LT and hepatectomy. METHODS: The study patients were 1599 LT recipients selected from the Korean Organ Transplantation Registry database. RESULTS: Deceased-donor and living-donor LTs were performed in 143 and 1456 cases, respectively. Weak correlation was present among AFP, DCP, and TV. The viable HCC group showed ADV score-dependent disease-free survival (DFS) and overall patient survival (OS) rates from 1log to 10log (p<0.001). Prognosis of complete pathological response group was comparable to that of ADV score <1log (p≥0.099). ADV score cutoff of 5log (ADV-5log) for DFS and OS was obtained through receiver operating characteristic curve analysis with area under the curve ≥0.705. Both ADV-5log and Milan criteria were independent risk factors for DFS and OS, and their prognostic impacts were comparable to each other. Combination of these two factors resulted in further prognostic stratification, showing hazard ratios for DFS and OS as 2.98 and 2.26 respectively for one risk factor and 7.92 and 8.19 respectively for two risk factors (p<0.001). ABO-incompatible recipients with ADV score ≥8log or two risk factors showed higher recurrence rates. CONCLUSIONS: This validation study revealed that ADV score is a reliable surrogate biomarker for posttransplant HCC prognosis, which can be used for selecting LT candidates and guiding risk-based posttransplant follow-up surveillance.

Convex Combination of Images From Dual-Layer Detectors for High Detective Quantum Efficiencies.

OBJECTIVE: In this paper, a novel dual-layer detector is considered to acquire X-ray images of high signal-to-noise ratio (SNR) as well as detective quantum efficiency (DQE) especially for high voltages of X-ray tubes. METHODS: To achieve a uniform alignment property, the upper and lower detector layers are stacked with an aligning procedure while minimizing the layer distance. A convex combination of the images acquired from the layers is optimized with respect to the combination coefficient. For the optimization and an alignment analysis based on Monte Carlo simulations, parametric modeling for the detector is also conducted. RESULTS: It is shown that for a given spatial frequency, the optimized DQE of the convex combination image (CCI) is the summation of the DQE values of the upper and lower layers. For extensive experiments, several types of the aligned dual-layer detector (ADD) are practically constructed to acquire CCI. The experimental results under a beam quality of RQA 9 showed that ADD could efficiently increase the DQE value from 50% to more than 75% at zero frequency. CONCLUSION: ADD can be used for increasing DQE as well as conventional spectral detector applications. SIGNIFICANCE: CCI acquired from ADD can have significantly higher DQE values compared to the single-layer cases.