Digital coincidence counting with 4πβ(PPC)-γ for the standardization of 60Co

A 4πβ(PPC)-γ coincidence system has been made at KRISS based on a digital DAQ. 60Co sources were measured to verify the system. The maximum detection efficiency for beta particles was estimated to be 96.7 %. Massic activities for sample sources had 0.005 % of the sample variability error, which was well within the expanded standard uncertainty of 0.54 % (k = 2).

A simplified cranial cavity model to understand the relationship between intracranial pressure and dural sinus pressure

Although accurate intracranial pressure (ICP) monitoring is essential for the diagnosis and treatment of severe brain diseases, current methods are performed invasively. Therefore, a safe and less invasive ICP measurement is required. The purpose of our study was to develop a simplified cranial cavity model for a better understanding of the relationship between the ICP and the pressure measurement within the dural venous sinus (DVS) to support the validity of using sinus pressure as the surrogate of the ICP. The in-house cranial cavity model had three components: the brain part, the DVS part, and the subarachnoid space (SAS) part. Pressure in other parts was measured when the pressure in the SAS part and, separately, brain part was increased from 0 (baseline) to 50 mmHg at intervals of 10 mmHg. When the pressure in the SAS part was increased from 10 to 50 mmHg at 10 mmHg interval, pressures of both the brain and DVS parts increased without significant difference (all P > 0.05). However, pressures in both the SAS and DVS parts differed while the pressure in the brain part was increased. The pressures in both parts showed about 70% of the increase in the brain part. Nevertheless, the pressures in the SAS and DVS parts were not significantly different (P > 0.05). A simplified in-house cranial cavity model was developed consisting of three compartments to represent the actual intracranial spaces. The pressure measurement within the DVS was feasible to use as a surrogate for the ICP measurement.

Intraductal papillary neoplasm of the bile duct: diagnostic value of MRI features in differentiating pathologic subclassifications-type 1 versus type 2

OBJECTIVES

To identify MRI features for differentiating type 2 from type 1 intraductal papillary neoplasms of bile duct (IPNB) and assessing malignant potential of IPNB.

METHODS

This retrospective study included 60 patients with surgically proven IPNB who had undergone preoperative MRI between January 2007 and December 2020. All surgical specimens were reviewed retrospectively to classify types 1 and 2 IPNBs and assess tumor grade. Significant MRI features for differentiating type 2 (n = 40) from type 1 IPNB (n = 20); and for IPNB with an associated invasive carcinoma (n = 43) from intraepithelial neoplasia (n = 17) were determined using logistic regression analysis.

RESULTS

An associated invasive carcinoma was more frequently found in type 2 than in type 1 IPNB (85.0% [34/40] vs. 45.0% [9/20], p = 0.003). At univariable analysis, MRI features including extrahepatic location, no dilatation of tumor-bearing segment of bile duct, isolated upstream bile duct dilatation, and single lesion were associated with type 2 IPNB (all p ≤ 0.012). At multivariable analysis, significant MRI findings for differentiating type 2 from type 1 IPNB were extrahepatic location and no dilatation of tumor-bearing segment of bile duct (odds ratio [OR], 7.24 and 46.40, respectively). At univariable and multivariable analysis, tumor size ≥ 2.5 cm (OR, 8.45), bile duct wall thickening (OR, 4.82), and irregular polypoid or nodular tumor shape (OR, 6.44) were significant MRI features for differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia.

CONCLUSION

MRI with MR cholangiopancreatography may be helpful in differentiating type 2 IPNB from type 1 IPNB and assessing malignant potential of IPNB.

CLINICAL RELEVANCE STATEMENT

Preoperative MRI with MR cholangiopancreatography may be helpful in differentiating type 2 intraductal papillary neoplasms of bile duct (IPNB) from type 1 IPNB and assessing malignant potential of IPNB.

KEY POINTS

• In terms of tumor grade, the incidence of invasive carcinoma was significantly higher in type 2 intraductal papillary neoplasm of the bile duct (IPNB) than in type 1 IPNB. • At MRI, extrahepatic location and no dilatation of tumor-bearing segment are significant features for differentiating type 2 IPNBs from type 1 IPNBs. • At MRI, large tumor size, bile duct wall thickening, and irregular polypoid or nodular tumor shape are significant features for differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia.

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

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

Three-dimensional navigation-guided percutaneous trans-symphyseal screw for mechanically unstable pubic symphysis diastasis

Minimally invasive trans-symphyseal screw (TSS) for pubic symphysis diastasis was recently advocated, and its feasibility and reproducibility under 3D-navigation guidance are explored. Fifteen cases between 2016 and 2021 with a background of pubic symphysis diastasis are reviewed in this case series. Twenty-two TSS were inserted with an average Injury Severity Score of 35.3. Sixty percent received a one-stage procedure including fracture reduction, intra-operative 3D imaging, and planning followed by execution. The mean operative time and blood loss were 132 minutes and 160 ml, respectively. Average fracture healing was 5.8 months with two delayed unions at 9 months. The pubic symphysis distance was maintained in all cases at 6 months post-op. The average Marjeed score, Multicenter Study Group Pelvic Outcome Score, and Numeric pain rating scale were 60.2, 6.5, and 2.7, respectively. We conclude that 3D-navigation-guided percutaneous TSS restores pelvic stability and provides satisfactory pain control, and thus a safe and effective alternative to open reduction internal fixation.

Thymidylate synthase accelerates Men1-mediated pancreatic tumor progression and reduces survival

Clinical studies of cancer patients have shown that overexpression or amplification of thymidylate synthase (TS) correlates with a worse clinical outcome. We previously showed that elevated TS exhibits properties of an oncogene and promotes pancreatic neuroendocrine tumors (PanNETs) with a long latency. To study the causal impact of elevated TS levels in PanNETs, we generated a mouse model with elevated human TS (hTS) and conditional inactivation of the Men1 gene in pancreatic islet cells (hTS/Men1^–/–). We demonstrated that increased hTS expression was associated with earlier tumor onset and accelerated PanNET development in comparison with control Men1^–/– and Men1^+/ΔN3-8 mice. We also observed a decrease in overall survival of hTS/Men1^+/– and hTS/Men1^–/– mice as compared with control mice. We showed that elevated hTS in Men1-deleted tumor cells enhanced cell proliferation, deregulated cell cycle kinetics, and was associated with a higher frequency of somatic mutations, DNA damage, and genomic instability. In addition, we analyzed the survival of 88 patients with PanNETs and observed that high TS protein expression independently predicted worse clinical outcomes. In summary, elevated hTS directly participates in promoting PanNET tumorigenesis with reduced survival in Men1-mutant background. This work will refocus attention on new strategies to inhibit TS activity for PanNET treatment.

Standardization of 129I using the movable 4πβ(LS)-X(NaI(Tl)) system

The ¹²⁹I standardization, using the movable 4πβ(LS)-X(NaI(Tl)) coincidence system, was performed for two ¹²⁹I radioactive sources - one was dissolved in 0.1M NaOH solution and the other in 0.1M HNO₃ solution. The system incorporates three movable PM tubes for a β-counter placed on a plane and a X-ray detector that can be moved up to the bottom of the vial. The β-efficiency depending on the amount of radioactive solution was investigated with 14 liquid scintillation samples prepared by gravimetrically dispensing 4.4-145 mg of ¹²⁹I radioactive solution. The β-efficiencies above 90% were observed at less than 56 mg, but it was at most 70% at 145 mg. This occurred regardless of the activity of the sample or the type of chemical solution used to dissolve ¹²⁹I source. The activity concentration of each ¹²⁹I source was determined by efficiency-extrapolation method for samples with an activity range of 0.28-4.5 kBq. The β-efficiency points were derived over 10 intervals by moving 3-PM tubes in fine steps of about 1 mm from the sample. The highest value for β-efficiency was 95%. The combined uncertainty were 0.25% and 0.26%, respectively. The stated precision obtained using the system is better than that previously reported in the literature obtained by the triple to double coincidence ratio (TDCR) or the CIEMAT/NIST efficiency tracing method.

How to approach pancreatic cancer after neoadjuvant treatment: assessment of resectability using multidetector CT and tumor markers

OBJECTIVES

To investigate clinical and CT factors associated with local resectability in patients with nonmetastatic pancreatic cancers after neoadjuvant chemotherapy ± radiation therapy (CRT).

METHODS

This retrospective study included consecutive patients with nonmetastatic pancreatic cancers who underwent neoadjuvant CRT between June 2009 and June 2019. Tumor size, tumor-vascular contact with artery/vein, and local resectability categories (resectable, borderline resectable, or locally advanced) were assessed at baseline and post-CRT CT. Baseline and post-CRT carbohydrate antigen (CA) 19-9 levels were also assessed. Clinical or imaging features related to R0 resection were determined using logistic regression analysis.

RESULTS

A total of 179 patients (mean age, 62.4 ± 9.3 years; 92 men) were included. After neoadjuvant CRT, 105 (58.7%) patients received R0 resection, while 74 (41.3%) did not. R0 resection rates were significantly different according to post-CRT CT resectability categories (p < 0.001): 82.8% (48/58), 70.1% (47/67), and 18.5% (10/54) for resectable, borderline resectable, and locally advanced disease, respectively. For post-CRT borderline resectable disease, ≥ 50% decrease in CA 19-9 was significantly associated with R0 resection (odds ratio (OR), 3.160; p = 0.02). For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm (OR, 9.668; p = 0.026) and decreased tumor-arterial contact (OR, 24.213; p = 0.022) were significantly associated with R0 resection.

CONCLUSION

Post-CRT CT resectability categorization may be useful for the assessment of R0 resectability in patients with pancreatic cancer following neoadjuvant CRT. Additionally, ≥ 50% decrease in CA 19-9 was associated with R0 resection in post-CRT borderline resectable disease, while small post-CRT tumor size and decreased tumor-arterial contact were with locally advanced disease.

KEY POINTS

• R0 resection rates following neoadjuvant chemotherapy ± radiation therapy (CRT) were 82.8%, 70.1%, and 18.5% in resectable, borderline resectable, and locally advanced disease, respectively, at post-CRT CT (p < 0.001). • For post-CRT borderline resectable disease, ≥ 50% decrease in carbohydrate antigen (CA) 19-9 was significantly associated with R0 resection. • For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm and decreased tumor-arterial contact were significantly associated with R0 resection.

A comparison of outcomes in patients with intracholecystic papillary neoplasms or conventional adenocarcinomas of the gallbladder

BACKGROUND

Intracholecystic papillary neoplasm (ICPN) of the gallbladder (GB) is an exophytic intraepithelial neoplasm. This study aimed to investigate clinicopathologic findings, prognosis and recurrence patterns of patients with ICPN as compared to those patients with conventional adenocarcinoma of the gallbladder (GBC).

METHODS

Patients who underwent surgical resection for suspected GB cancer between 2000 and 2018 were included. ICPN was defined as an exophytic papillary mass within the GB lumen with a size ≥1.0 cm.

RESULTS

Of 607 patients, 241 patients (40%) were pathologically diagnosed with ICPN. Of the 241 patients with ICPNs, 110 (46%) were T1 or less. Following T stage-matched analysis, the rate of lymph node metastases were comparable (50 [52%] vs. 37 [49%], P = 0.581). The five-year survival rate was higher in ICPN, but after T stage-matching, they were comparable (69.1 vs. 63.2%, P = 0.171). Overall recurrence rates were also comparable, with the exception of lower peritoneal seeding in patients with ICPN.

CONCLUSION

Patients with ICPN who underwent resection were more likely to have an earlier T stage. There was no significant difference in prognosis and recurrence between ICPN and conventional GBC after stage matching. Therefore, the treatment strategy for ICPN should follow the same protocols used for conventional GBC.

Development of a movable 4πβ(LS)-γ coincidence counting system for activity standardization of β-γ emitters

A new movable 3PM-γ coincidence system, based on 4πβ(LS)-γ coincidence counting, for activity measurement of β-γ emitters has been designed at the Korea Research Institute of Standards and Science (KRISS). The system incorporates 3 PM tubes on the plane and two detectors placed above and below the center of the plane. The 3 PM tubes for β-counters in the plane are movable up to 100 mm from a liquid scintillation vial, thus enabling the variation of β-detection efficiencies by a geometrical technique. A NaI(Tl) γ-counter was set above for the present work. The β-event is determined by counting the logical sum of three double coincidences. All the necessary electronics, i.e., logical sum, adjusting the duration of dead-time of each counting channel and coincidence resolving times, and analyzing coincidence relation, were specially designed to be fabricated in an integrated circuit. Details of the detectors, the electronics, the overall movable 3PM-γ coincidence system are presented, as well as the results of investigations to assess its operating characteristics. Validation measurements have been performed with ⁶⁰Co and ⁵⁷Co sources. The highest β-detection efficiency achieved with ⁶⁰Co and ⁵⁷Co was 97% and 95%, respectively. The activity concentration determined with a new system agreed with calibrated values within the uncertainty range. Further results from validation measurements and the corresponding uncertainty budgets are presented.

Evaluation of LI-RADS Version 2018 Treatment Response Algorithm for Hepatocellular Carcinoma in Liver Transplant Candidates: Intraindividual Comparison between CT and Hepatobiliary Agent-enhanced MRI

Background The Liver Imaging Reporting and Data System (LI-RADS), version 2018, treatment response algorithm (TRA) is used to assess hepatocellular carcinoma (HCC) after local-regional therapy (LRT). However, its diagnostic performance has not yet been fully compared between CT and hepatobiliary agent (HBA)-enhanced MRI in patients who have undergone liver transplant (LT). Purpose To compare the diagnostic performance of LI-RADS TRA when using CT versus using HBA-enhanced MRI in an intraindividual manner according to pathologic results. Materials and Methods Between January 2011 and September 2019, 165 patients with 237 clinically suspected HCCs underwent LRT followed by LT and were retrospectively included. All patients underwent both CT and HBA-enhanced MRI after LRT and before LT. Three radiologists independently assessed tumor viability with both modalities by using LI-RADS TRA and reached a consensus. Pathologic tumor viability categorized as either completely (100%) or incompletely (<100%) necrotic obtained from the explanted liver served as the reference standard. Sensitivity and specificity of the LI-RADS TRA in the consensus reading were then compared between CT and HBA-enhanced MRI by using the ratio estimator approach. Interobserver agreements were calculated by using Fleiss κ statistics. Results There were 165 patients (mean age, 62 years ± 9 [standard deviation]; 135 men) with a total of 237 lesions, of which 107 were viable tumors (45.1%) at pathologic evaluation. With the LI-RADS TRA, sensitivity and specificity of the viable category for detection of viable HCCs at pathologic evaluation were 42.1% (45 of 107 lesions) and 95.4% (124 of 130 lesions) with CT and 52.3% (56 of 107 lesions) and 93.9% (122 of 130 lesions) with HBA-enhanced MRI, with a significant difference in sensitivity but not specificity (P = .009 and P = .42, respectively). Interobserver agreements for the LI-RADS TRA were substantial for both CT and HBA-enhanced MRI (κ, 0.69 for both). Conclusion In patients who underwent local-regional therapy for hepatocellular carcinoma before liver transplant, hepatobiliary agent-enhanced MRI was more sensitive than CT in evaluating tumor viability with the Liver Imaging Reporting and Data System, version 2018, treatment response algorithm. ©RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Bashir and Mendiratta-Lala in this issue.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

The primary system for measurement of beta emitting radioactive gases at KRISS

Korea Research Institute of Standards and Science (KRISS) is developing a length-compensated proportional counting (LCPC) system as a primary system for standardization of beta emitting radioactive gases. The pilot experiment was performed with ⁸⁵Kr and the optimized high voltage and pressure were found to be 1700 V and 0.203 MPa, respectively. The total activity of ⁸⁵Kr was deduced by the length compensation of each count. The expanded uncertainty was estimated to be around 0.8% (k = 2) for the ⁸⁵Kr measurement.

Design of optimal digital filter and digital signal processing for a CdZnTe high resolution gamma-ray system

We have developed an online digital signal processing system based on an FPGA. The system consists of pile-up rejection, baseline restorer, peak detection and pole-zero cancellation for evaluation of deposited energy in the detector. The shaping algorithm employed is a Moving Window Deconvolution (MWD) to shape digitized data into a trapezoidal form. For the purpose of verification, the developed digital system was tested for ¹³⁷Cs gamma rays. The entire system is programmed using the LabVIEW environment.

Risk Factors of Tumor Recurrence After Liver Transplantation for Combined Hepatocellular Carcinoma and Cholangiocarcinoma

BACKGROUND

Combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) is commonly diagnosed as hepatocellular carcinoma (HCC) preoperatively. Therefore, unexpected recurrence occurs in some patients after liver transplantation (LT). The aim of this study was to identify the risk factors of recurrence.

METHODS

We retrospectively reviewed the data of 20 patients who underwent LT for cHCC-CC from January 2005 to December 2015.

RESULTS

Of the 20 patients, 11 (55%) had concurrent HCC and 10 (50%) had multiple cHCC-CCs. Before LT, 13 patients had undergone transarterial chemoembolization (TACE, n = 9), radiofrequency ablation, and TACE (n = 3) or surgical resection (n = 1). Four of the patients (20%) had the classical type, whereas 16 (80%) had subtypes with stem cell features. Six of the 16 patients (37.5%) with subtypes with stem cell features and 3 of the 4 patients (75%) with the classical type showed recurrence after LT. In multivariate analysis, the classical type was significantly associated with poorer recurrence-free survival (RFS) (hazard ratio [HR]: 8.65, confidence interval [CI]: 1.25-60.05, P = .03) and poorer overall survival (HR: 8.89, CI: 1.37-57.84, P = .02). Spontaneous tumor necrosis also showed significance on RFS (P = .03) among 11 patients with nontreated lesions.

CONCLUSION

In cHCC-CC, the classical type and spontaneous tumor necrosis were associated with recurrence. If these risk factors are found after LT, short-interval follow-up and strategies such as chemotherapy and/or use of mammalian target of rapamycin inhibitors to prevent recurrence are needed.

Association between time to treatment and functional outcomes according to the Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score in endovascular stroke therapy

BACKGROUND AND PURPOSE

The rate at which the chance of a good outcome of endovascular stroke therapy (EVT) decays with time when eligible patients are selected by baseline diffusion-weighted magnetic resonance imaging (DWI-MRI) and whether ischaemic core size affects this rate remain to be investigated.

METHODS

This study analyses a prospective multicentre registry of stroke patients treated with EVT based on pretreatment DWI-MRI that was categorized into three groups: small [Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS)] (8-10), moderate (5-7) and large (<5) cores. The main outcome was a good outcome at 90 days (modified Rankin Scale 0-2). The interaction between onset-to-groin puncture time (OTP) and DWI-ASPECTS categories regarding functional outcomes was investigated.

RESULTS

Ultimately, 985 patients (age 69 ± 11 years; male 55%) were analysed. Potential interaction effects between the DWI-ASPECTS categories and OTP on a good outcome at 90 days were observed (P_interaction  = 0.06). Every 60-min delay in OTP was associated with a 16% reduced likelihood of a good outcome at 90 days amongst patients with large cores, although no associations were observed amongst patients with small to moderate cores. Interestingly, the adjusted rates of a good outcome at 90 days steeply declined between 65 and 213 min of OTP and then remained smooth throughout 24 h of OTP (P_nonlinearity  = 0.15).

CONCLUSIONS

Our study showed that the probability of a good outcome after EVT nonlinearly decreased, with a steeper decline at earlier OTP than at later OTP. Discrepant effects of OTP on functional outcomes by baseline DWI-ASPECTS categories were observed. Thus, different strategies for EVT based on time and ischaemic core size are warranted.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Tumor-Associated Protein Profiles in Kaposi Sarcoma and Mimicking Vascular Tumors, and Their Pathological Implications

We investigated protein profiles specific to vascular lesions mimicking Kaposi sarcoma (KS), based on stepwise morphogenesis progression of KS. We surveyed 26 tumor-associated proteins in 130 cases, comprising 39 benign vascular lesions (BG), 14 hemangioendotheliomas (HE), 37 KS, and 40 angiosarcomas (AS), by immunohistochemistry. The dominant proteins in KS were HHV8, lymphatic markers, Rb, phosphorylated Rb, VEGF, and galectin-3. Aberrant expression of p53, inactivation of cell cycle inhibitors, loss of beta-catenin, and increased VEGFR1 were more frequent in AS. HE had the lowest Ki-67 index, and the inactivation rates of cell cycle inhibitors in HE were between those of AS and BG/KS. Protein expression patterns in BG and KS were similar. Clustering analysis showed that the 130 cases were divided into three clusters: AS-rich, BG-rich, and KS-rich clusters. The AS-rich cluster was characterized by high caveolin-1 positivity, abnormal p53, high Ki-67 index, and inactivated p27. The KS-rich cluster shared the features of KS, and the BG-rich group had high positive expression rates of galectin-3 and low bcl2 expression. In conclusion, although the rate was different, AS and HE tended to have less cell cycle marker expression than KS, and features of BG and activated KS cell signaling were similar.

A unified multidisciplinary fragility hip fracture pilot pathway in a trauma centre in Hong Kong: One-year outcome in the acute phase

Introduction:

The growing impact of fragility hip fracture (FHF) on the healthcare system and the society has become a major concern worldwide. A unified multidisciplinary FHF pathway from admission to rehabilitation and back to community was established in 2015. The acute phase of the pathway was put into pilot in our hospital to evaluate the outcome.

Method:

A designated FHF team was established in our centre since January 2015. The FHF pathway was piloted since June 2015. Patients admitted with a hip fracture resulting from fall on standing height were included. Major outcome parameters were compared in three phases: (1) before FHF team and FHF pathway (January to December 2014), (2) after FHF team but before FHF pathway (January to May 2015) and (3) after FHF team and FHF pathway (June 2015 to May 2016).

Result:

In phases 1, 2 and 3, 631, 263 and 634 patients were included, respectively. From phases 1 to 3, the average key performance indicator (KPI) has improved from 49.2% to 65.8% to 70.0% significantly; average acute length of stay (days) has improved from 13.7 to 13.4 to 11.3 significantly; total surgical complication rates have improved from 6.2% to 7.6% to 5.8%. The 30-day mortality rate and the unplanned readmission rate (within 28 days) have remained below 2.7% and 2.2%, respectively.

Conclusions:

Implementation of an FHF pathway can form a multidisciplinary platform that can improve the standard of care and outcome for our FHF patients in terms of KPI and also length of stay.

New knowledge added by this study:

A newly designed and implemented fragility hip fracture pathway in our centre as a pilot with the results evaluated.

Implications for clinical practice or policy:

With the increasing elderly population in Hong Kong and globally, there is a need to design and implement a fragility hip fracture (FHF) pathway to improve the care and effectiveness for FHF patients.

Abstract P3-03-31: Is sentinel lymph node biopsy necessary in all patients with early breast cancer?

Background and objectives : Since the results of the American College of Surgeons Oncology Group Z0011 published, the criteria for applying axillary lymph node (ALN) dissection was relaxed among early breast cancer patients who were scheduled for breast conserving surgery, adjuvant chemotherapy therapy, and adjuvant radiation therapy. SLNB criteria may be established if pathologic nodal status can be predicted. The aim of this study was to develop a nomogram for preoperative prediction of axillary node metastasis.

Methods: The records of 1650 patients with T1, T2 primary invasive breast cancer who were treated between January 2013 and September 2016 were selected from the medical database of Yonsei University (Seoul, South Korea). Those whom a preoperative diagnosis of axillary node metastases were excluded. Two nomogram that predicted three or more axillary metastasis and one or more axillary metastasis were developed using a binary logistic regression model with a training cohort. Internal validation was carried out adopting bootstrap method by validation cohort 500 times resampling.

Result: A total of 82 (4.8%) patients had three or more ALNs metastasis. Three hundred seventy five (17.4%) patients had one or more ALNs metastasis. Axillary metastasis was associated with Preoperative ALN suspicious image findings, clinical tumor size, Number of neoplastic foci, estrogen receptor status, Ki-67 expression, tumor marker. The nomogram was developed based on the clinical and statistically significant predictors. It had good discrimination performance (AUC 0.79, 95% CI, 0.73–0.85), (AUC 0.71, 95% CI, 0.67–0.74) and calibration fit.

Conclusion:Our nomogram might help predict the ALN metastasis in breast cancer patients. Patients with a low probability of ALN metastasis could be spared SLNB.

Citation Format: Yoon KH, Lee KB, Lee H, Lee J, Kim JY, Park HS, Park S, Kim SI, Cho YU, Park B-W. Is sentinel lymph node biopsy necessary in all patients with early breast cancer? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-31.

Abstract OT2-01-03: A prospective pilot study of simultaneous robotic assisted nipple sparing mastectomy and immediate reconstruction

Endoscopic breast surgery was expected to be an adequate technique to complete cancer clearance and preservation of the patient's body image. However, this technique has limitations including incomplete internal movements and unstable vision of a two dimensional camera due to inflexible endoscopic instruments especially during the skin flap formation. High resolution, ten-fold image magnification, and three-dimensional optics of robotic surgery help overcome the limitations of endoscopic surgery, and thus robotic surgery has been adopted in a wide range of intracorporeal procedures including breast surgery. However, few studies have evaluated feasibility and safety of robotic assisted nipple sparing mastectomy (RANSM) and immediate breast reconstruction (IBR) for the treatment of breast cancer. There were not any investigation to assess patients' satisfaction of cosmetic effect after performing RANSM and IBR. This study is aim to verify the feasibility and the safety of RANSM and IBR and to analyze cosmetic effect of the procedure and satisfaction of patients. The target number of enrollments is 15 patients. Patients who are diagnosed with early breast cancer or BRCA 1/2 mutation carriers are enrolled. Female patients over 20 years old who are candidates to preserve nipple areolar complex and considered to perform reconstruction with implants are prospectively collected. Written informed consents are mandatory. Patients who are considered the high possibility of postoperative radiation therapy according to preoperative stage are not included in this study. We exclude patients who want to undergo other methods of breast reconstruction than breast reconstruction with implants. Patients will undergo RANSM and IBR through a single axillary skin incision simultaneously. Regular follow-up at 1 month and 6 months after RANSM and IBR is scheduled to record recovery of a patient, amount of a drain, date of drain removal, and postoperative complications. Patient satisfaction questionnaire will be completed on the last follow-up day. To evaluate the safety of robotic assisted surgery, the oncologic safety (margin status of nipple areolar complex), postoperative recovery of a patient, and postoperative complications are investigated. We compare preoperative and postoperative 6 month photographs of patients and estimate the surgical outcome by objective indicators to evaluate the cosmetic grading by plastic surgeons. Patients' satisfaction are assessed by questionnaire (BREAST-Q) at the 6-month visit.

Citation Format: Lee J, Park HS, Kim JH, Lee DW, Song SY, Lew DH, Kim JY, Kim SI, Cho YU, Lee H, Lee KB, Yoon KH. A prospective pilot study of simultaneous robotic assisted nipple sparing mastectomy and immediate reconstruction [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-01-03.

Alteration of MRP2 expression and the graft outcome after liver transplantation

Purpose

Multidrug resistance-associated protein (MRP) 2 is a glutathione conjugate in the canalicular membrane of hepatocytes. Early graft damage after liver transplantation (LT) can result in alteration of MRP2 expression. The purpose of this study was to evaluate the relationship between the pattern of MRP2 alteration and graft outcome.

Methods

Forty-one paraffin-embedded liver graft tissues obtained by protocol biopsy within 2 months after LT; these were stained using monoclonal antibodies of MRP2. We selected 15 live donor biopsy samples as a control, that showed homogenous canalicular staining for MRP2. The pattern of canalicular MRP2 staining of graft was classified into 3 types: homogenous (type C0), focal (type C1), and no (type C2,) staining of the canaliculi.

Results

In total, 17.1% graft tissues were type C0, 36.6% were type C1, and 46.3% were type C2. The median operation time was longer in patients with type C2 (562.6 minutes) than in patients with type C0 (393.8 minutes) (P = 0.038). The rates of posttransplant complications were higher in patients with type C2 (100%) than in patients with type C0 (42.9%) and C1 (73.3%) (P < 0.001).

Conclusion

MRP2 expression pattern was altered in 82.9% after LT. The pattern of MRP2 alteration was associated with longer operation time and higher rates of post-LT complications.

A portable high-intensity focused ultrasound system for the pancreas with 3D electronic steering: a preclinical study in a swine model

PURPOSE

The aim of this animal study was to evaluate the safety and feasibility of a portable, ultrasonography-guided, high-intensity focused ultrasound (USg-HIFU) system to treat the pancreas.

METHODS

Eight swine were included. Using a portable HIFU device (ALPIUS 900, Alpinion Medical Systems), ablations were performed on the pancreas in vivo. Different acoustic intensities were applied (1.7 kW/cm2 or 1.5 kW/cm2 , n=2 [group A for a pilot study]; 1.5 kW/ cm2 , n=3 [group B]; and 1.2 kW/cm2 , n=3 [group C]). Magnetic resonance imaging (MRI) was performed immediately (group A) or 7 days (groups B and C) after HIFU treatment. In groups B and C, serum amylase and lipase levels were measured on days 0 and 7, and performance status was observed every day. Necropsy was performed on days 0 (group A) or 7 (groups B and C) to assess the presence of unintended injuries and to obtain pancreatic and peripancreatic tissue for histological analysis.

RESULTS

Ablation was noted in the pancreas in all swine on MRI, and all pathologic specimens showed coagulation necrosis in the treated area. The mean ablation areas on MRI were 85.3±38.1 mm2, 90.7±21.2 mm2, and 54.4±30.6 mm2 in groups A, B, and C, respectively (P>0.05). No animals showed evidence of complications, except for one case of a pseudocyst in group B.

CONCLUSION

This study showed that pancreas ablation using a portable USg-HIFU system may be safe and feasible, and that coagulation necrosis of the pancreas was successfully achieved with a range of acoustic intensities.

Reduced expression of the RNA-binding protein HuD in pancreatic neuroendocrine tumors correlates with low p27Kip1 levels and poor prognosis

For the majority of patients diagnosed with pancreatic neuroendocrine tumors (NETs), there is significant malignant potential with a poor prognosis; however, the molecular abnormalities and pathogenesis of pancreatic NETs have not been firmly established. Here, we report that loss of expression of the RNA-binding protein HuD correlates with low p27^Kip1 (p27) levels and poor prognosis in pancreatic NETs. HuD expression was frequently lost in many human pancreatic NETs, and these pancreatic NETs showed aggressive clinicopathological phenotypes with low p27 levels, increased tumor size, higher World Health Organization grade and pT stage of the tumor, and the presence of angioinvasion. Furthermore, loss of HuD was an independent, progression-free prognostic factor in multivariate survival analysis. However, the level of HuR, a member of the same Hu protein family as HuD, was not significantly correlated with pancreatic NET size and progression. Mechanistically, HuD enhanced p27 mRNA translation by interacting with both the 5'-untranslated region (UTR) and the 3'-UTR of p27 mRNA, and consequently suppressed cell cycle progression and tumor growth. In addition, HuD competed with miR-30a-3p for binding to the 3'-UTR of p27 mRNA, suggesting an interplay between HuD and miR-30a-3p in controlling p27 translation. Our results identify HuD as a pivotal suppressor of pancreatic NET growth, and suggest that HuD has potential value as a prognostic factor of pancreatic NETs. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Results of an international comparison of activity measurements of 68Ge

An international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11)kBqg-1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence.

Evaluation of abundance of artificial radionuclides in food products in South Korea and sources

Food samples are collected nationwide from January 2016 to February 2017 and their contents of artificial radionuclides are measured to address the growing concerns regarding the radioactive contamination of food products in Korea. Specifically, 900 food samples are collected for this study and their contents of representative artificial radionuclides ¹³⁴Cs, ¹³⁷Cs, ^239,240Pu, and ⁹⁰Sr are analyzed. The analysis shows that the activity concentrations of ¹³⁷Cs in fish range from minimum detectable activity (MDA) to 340 mBq/kg of fresh weight. The concentration factor (CF) determined for ¹³⁷Cs as a measure of its bioavailability is calculated to be ca. 74 and found to be very similar to that (100) recommended by the International Atomic Energy Agency. With an MDA of <0.221 mBq/kg, the results reveal that ^239,240Pu values in fish are below the MDA. The activity concentrations of ¹³⁷Cs and ⁹⁰Sr are lower than the MDA in both shellfish and seaweed, while the activity concentrations of ^239,240Pu in shellfish range from 0.26 to 2.18 mBq/kg, and for seaweed samples range from 2.07 to 3.38 mBq/kg. The atom ratios of ²⁴⁰Pu/²³⁹Pu in shellfish caught at the Korean coast vary from 0.209 to 0.237, with a mean of 0.227. The higher ²⁴⁰Pu/²³⁹Pu atom ratio determined in shellfish is thought to be caused by the plutonium transported from the Pacific Proving Grounds rather than other sources such as the Fukushima nuclear power plant accident. The activity concentrations of ¹³⁷Cs in mushrooms are found to vary from 1.0 to 21.4 Bq/kg, with the highest concentrations observed in the Oak (shiitake) and Sarcodon asparatus. ¹³⁴Cs is detected in three mushroom specimens collected from Jeju Island and about 3-3.6% of ¹³⁷Cs present in the wild mushrooms native to the Jeju Island are introduced as a result of the Fukushima nuclear plant accident. The annual effective doses of ¹³⁷Cs received through consumption of mushrooms and fish are 2.0 × 10^-4 mSv yr^-1 and 3.9 × 10^-5 mSv yr^-1, and those values are negligible compared to the annual effective doses limit of 1 mSv yr^-1.

Ceruloplasmin as a prognostic marker in patients with bile duct cancer

BACKGROUND AND AIMS

Bile duct cancer is one of the lethal cancers, presenting difficulties in early diagnosis and limited treatment modalities. Despite current advances in biomarker research, most studies have been performed in Western populations. Therefore, the purpose of this study was to determine a prognostic marker for bile duct cancer, especially in Korean patients, whose incidence of bile duct cancer is high.

RESULTS

Comparing cancer and normal bile duct tissue, we identified 29091 differentially expressed genes. CP, SCEL, and MUC16 had positive coefficients with a log2 ratio >1 for advanced T, N stage and perineural invasion cancer tissue. Strong immunohistochemical expression of ceruloplasmin was dominant in tumors with advanced T stage (p>0.999) and perineural invasion (p=0.316).

PATIENTS AND METHODS

We performed tissue microarray experiment with 79 bile duct cancer tissue samples and 21 normal bile duct tissue samples. Candidate genes that has positive correlation with T, N stage and perineural invasion were drawn with multivariate analysis. Tissue expression of the genes was evaluated with an immunohistochemical study.

CONCLUSIONS

Ceruloplasmin is supposed to be related with advanced T stage and perineural invasion, having a possibility as a candidate prognostic marker for bile duct cancer.

Prognostic significance of E-cadherin and ZEB1 expression in intraductal papillary mucinous neoplasm

There is an urgent need to investigate the genetic changes that occur in intraductal papillary mucinous neoplasm (IPMN), which is a well-known precursor of pancreatic cancer. In this study, gene expression profiling was performed by removing unwanted variation to determine the differentially expressed genes (DEGs) associated with malignant progression of IPMN. Among the identified DEGs, zinc finger E-box binding homeobox 1 (ZEB1) and E-cadherin, a crucial regulator of epithelial-to-mesenchymal transition (EMT), was validated among identified DEGs.

A total of 76 fresh-frozen tissues were used for gene expression profiling and formalin-fixed, paraffin-embedded blocks from 87 patients were obtained for immunohistochemical analysis. Loss of E-cadherin expression (p = 0.023, odd ratio [OR] = 4.923) and expression of ZEB1 in stromal cells (stromal ZEB1, p < 0.001, OR = 26.800) were significantly correlated with degree of dysplasia. The hazard of death was significantly increased in patients with loss of E-cadherin expression (hazard ratio [HR] = 13.718, p = 0.004), expression of epithelial ZEB1 (HR = 19.117, p = 0.001), and stromal ZEB1 (HR = 6.373, p = 0.043).

Based on the results of this study, loss of E-cadherin and expression of stromal ZEB1 are associated with increased risk of malignant progression. Epithelial and stromal ZEB1, as well as E-cadherin may be strong predictors of survival in patients with IPMN. Our finding suggests that these EMT markers may be utilized as potential prognosticators and may be used to improve and personalize treatment of IPMN.

Split liver transplantation for retroperitoneal immature teratoma masquerading as hepatoblastoma

Extragonadal teratoma originating from the retroperitoneum represents less than 5% of all teratomas and accounts for less than 10% of all pediatric retroperitoneal neoplasms. To date, there has been no report of teratoma managed with LT. This study reports an infant aged 3 months with retroperitoneal immature teratoma involving the hepatic hilum, refractory to chemotherapy and treated with LT. The patient was referred to our hospital for management of a growing abdominal mass. Histopathology of a fine needle biopsy of the lesion suggested the possibility of a hepatoblastoma with teratoid features. Cisplatin-based chemotherapy was initiated, but rapid growth of the tumor encasing the hepatic artery proper was detected, even after two cycles of chemotherapy. A split LT was carried out, and pathological examination of the explanted liver revealed the involvement of numerous neuroepithelial components, confirming the diagnosis of a Norris grade 3 immature teratoma. The patient recovered well and was discharged on day 19 post-LT. As on date, on postoperative day 240, he has completed seven cycles of a 12-cycle vinblastine and doxorubicin-based adjuvant chemotherapy.

Survival outcome and prognostic factors of neoadjuvant treatment followed by resection for borderline resectable pancreatic cancer

Purpose

Neoadjuvant treatment may provide improved survival outcomes for patients with borderline resectable pancreatic cancer (BRPC). The purpose of this study is to evaluate the clinical outcomes of neoadjuvant treatment and to identify prognostic factors.

Methods

Forty patients who met the National Comprehensive Cancer Network definition of BRPC and received neoadjuvant treatment followed by surgery between 2007 and 2015 were evaluated. Prospectively collected clinicopathological outcomes were analyzed retrospectively.

Results

The mean age was 61.7 years and the male-to-female ratio was 1.8:1. Twenty-six, 3, and 11 patients received gemcitabine-based chemotherapy, 5-fluorouracil, and FOLFIRINOX, respectively. The 2-year survival rate (2YSR) was 36.6% and the median overall survival (OS) was 20 months. Of the 40 patients, 34 patients underwent resection and the 2YSR was 41.2% while the 2YSR of patients who did not undergo resection was 16.7% (P = 0.011). The 2YSR was significantly higher in patients who had partial response compared to stable disease (60.6% vs. 24.3%, P = 0.038), in patients who did than did not show a CA 19-9 response after neoadjuvant treatment (40.5% vs. 0%, P = 0.039) and in patients who did than did not receive radiotherapy (50.8% vs. 25.3%, P = 0.036). Five patients had local recurrence and 17 patients had systemic recurrence with a median disease specific survival of 15 months.

Conclusion

Neoadjuvant treatment followed by resection is effective for BRPC. Pancreatectomy and neoadjuvant treatment response may affect survival. Effective systemic therapy is needed to improve long-term survival since systemic metastasis accounts for a high proportion of recurrence.

Focal segmental glomerulosclerosis and medullary nephrocalcinosis in children with ADCK4 mutations

BACKGROUND

Mutations in the AarF domain containing kinase 4 gene (ADCK4), one of the novel genes causing steroid-resistant nephrotic syndrome (SRNS), usually manifest as isolated adolescent-onset focal segmental glomerulosclerosis (FSGS). ADCK4 interacts with components of the coenzyme Q10 (CoQ10) biosynthesis pathway.

METHODS

The incidence and phenotypes of patients with ADCK4 mutations were investigated in a cohort of Korean pediatric patients with SRNS.

RESULTS

Among the 53 patients enrolled in the study the incidence of ADCK4-associated FSGS was 7.5% (n = 4) in children aged 5 years and older with multidrug-resistant FSGS. Two additional patients were included for phenotype analyses, one detected by family screening and the other with cyclosporine-responsive FSGS. These six patients presented proteinuria without overt nephrotic syndrome at a median age of 110 (range 60-153) months, of whom five progressed to end-stage renal disease within a median period of 46 (range 36-79) months after onset. Renal biopsies revealed mitochondrial abnormalities in podocytes and tubular cells of all patients. Notably, all patients showed accompanying medullary nephrocalcinosis. None of the patients showed other extrarenal manifestations.

CONCLUSIONS

ADCK4 mutations should be considered in older children presenting with steroid resistant FSGS. An early diagnosis of ADCK4 mutations is essential because the condition is treatable with CoQ10 supplementation at an early stage. The association with medullary nephrocalcinosis may be an additional diagnostic indicator.

Systematic influences on the areas of peaks in gamma-ray spectra that have a large statistical uncertainty

A method is presented for calculating the expected number of counts in peaks that have a large relative peak-area uncertainty and appear in measured gamma-ray spectra. The method was applied to calculations of the correction factors for peaks occurring in the spectra of radon daughters. It was shown that the factors used for correcting the calculated peak areas to their expected values decrease with an increasing relative peak-area uncertainty. The accuracy of taking the systematic influence inducing the correction factors into account is given by the dispersion of the correction factors corresponding to specific peaks. It was shown that the highest accuracy is obtained in the peak analyses with the GammaVision and Gamma-W software.

Liver fibrosis staging with a new 2D-shear wave elastography using comb-push technique: Applicability, reproducibility, and diagnostic performance

Objective

To evaluate the applicability, reproducibility, and diagnostic performance of a new 2D-shear wave elastography (SWE) using the comb-push technique (2D CP-SWE) for detection of hepatic fibrosis, using histopathology as the reference standard.

Materials and methods

This prospective study was approved by the institutional review board, and informed consent was obtained from all patients. The liver stiffness (LS) measurements were obtained from 140 patients, using the new 2D-SWE, which uses comb-push excitation to produce shear waves and a time-aligned sequential tracking method to detect shear wave signals. The applicability rate of 2D CP-SWE was estimated, and factors associated with its applicability were identified. Intraobserver reproducibility was evaluated in the 105 patients with histopathologic diagnosis, and interobserver reproducibility was assessed in 20 patients. Diagnostic performance of the 2D CP-SWE for hepatic fibrosis was evaluated by receiver operating characteristic (ROC) curve analysis.

Results

The applicability rate of 2D CP-SWE was 90.8% (109 of 120). There was a significant difference in age, presence or absence of ascites, and the distance from the transducer to the Glisson capsule between the patients with applicable LS measurements and patients with unreliable measurement or technical failure. The intraclass correlation of interobserver agreement was 0.87, and the value for the intraobserver agreement was 0.95. The area under the ROC curve of LS values for stage F2 fibrosis or greater, stage F3 or greater, and stage F4 fibrosis was 0.874 (95% confidence interval [CI]: 0.794–0.930), 0.905 (95% CI: 0.832–0.954), and 0.894 (95% CI: 0.819–0.946), respectively.

Conclusion

2D CP-SWE can be employed as a reliable method for assessing hepatic fibrosis with a reasonably good diagnostic performance, and its applicability might be influenced by age, ascites, and the distance between the transducer and Glisson capsule.

How well are we managing fragility hip fractures? A narrative report on the review with the attempt to setup a Fragility Fracture Registry in Hong Kong

INTRODUCTION

In setting up a disease registry for fragility fractures in Hong Kong, we conducted a retrospective systematic study on the management of fragility hip fractures. Patient outcomes were compared with the standards from our orthopaedic working group and those from the British Orthopaedic Association that runs a mature fracture registry in the United Kingdom.

METHODS

Clinical data on fragility hip fracture patients admitted to six acute major hospitals in Hong Kong in 2012 were captured. These included demographics, pre- and post-operative assessments, discharge details, complications, and 1-year follow-up information. Analysis was performed according to the local standards with reference to those from the British Orthopaedic Association.

RESULTS

Overall, 91.0% of patients received orthopaedic care within 4 hours of admission and 60.5% received surgery within 48 hours. Preoperative geri-orthopaedic co-management was received by 3.5% of patients and was one of the reasons for the delayed surgery in 22% of patients. Only 22.9% were discharged with medication that would promote bone health. Institutionalisation on discharge significantly increased by 16.2% (P<0.001). Only 35.1% of patients attended out-patient follow-up 1 year following fracture, and mobility had deteriorated in 69.9% compared with the premorbid state. Death occurred in 17.3% of patients within a year of surgery compared with 1.6% mortality rate in a Hong Kong age-matched population.

CONCLUSIONS

The efficiency and quality of acute care for fragility hip fracture patients was documented. Regular geri-orthopaedic co-management can enhance acute care. Much effort is needed to improve functional recovery, prescription of bone health medications, attendance for follow-up, and to decrease institutionalisation. A Fracture Liaison Service is vital to improve long-term care and prevent secondary fractures.

No-touch radiofrequency ablation using multiple electrodes: An in vivo comparison study of switching monopolar versus switching bipolar modes in porcine livers

Objective

To evaluate the in vivo technical feasibility, efficiency, and safety of switching bipolar (SB) and switching monopolar (SM) radiofrequency ablation (RFA) as a no-touch ablation technique in the porcine liver.

Materials and methods

The animal care and use committee approved this animal study and 16 pigs were used in two independent experiments. In the first experiment, RFA was performed on 2-cm tumor mimickers in the liver using a no-touch technique in the SM mode (2 groups, SM1: 10 minutes, n = 10; SM2: 15 minutes, n = 10) and SB-mode (1 group, SB: 10 minutes, n = 10). The technical success with sufficient safety margins, creation of confluent necrosis, ablation size, and distance between the electrode and ablation zone margin (DEM), were compared between groups. In the second experiment, thermal injury to the adjacent anatomic organs was compared between SM-RFA (15 minutes, n = 13) and SB-RFA modes (10 minutes, n = 13).

Results

The rates of the technical success and the creation of confluent necrosis were higher in the SB group than in the SM1 groups (100% vs. 60% and 90% vs. 40%, both p < 0.05). The ablation volume in the SM2 group was significantly larger than that in the SB group (59.2±18.7 cm³ vs. 39.8±9.7 cm^3,p < 0.05), and the DEM in the SM2 group was also larger than that in the SB group (1.39±0.21 cm vs. 1.07±0.10 cm, p < 0.05). In the second experiment, the incidence of thermal injury to the adjacent organs and tissues in the SB group (23.1%, 3/13) was significantly lower than that in the SM group (69.2%, 8/13) (p = 0.021).

Conclusion

SB-RFA was more advantageous for a no-touch technique for liver tumors, showing the potential of a better safety profile than SM-RFA.

False Positive Diagnosis of Hepatocellular Carcinoma in Liver Resection Patients

The diagnosis of hepatocellular carcinoma (HCC) is based on imaging studies particularly in high-risk patients without histologic confirmation. This study evaluated the prevalence and characteristics of false-positively diagnosed HCC in a liver resection cohort for HCC. A retrospective review was performed of 837 liver resection cases for clinically diagnosed HCC between 2005 and 2010 at our institute. High-risk patients with tumors > 1 cm with one or two image findings consistent with HCC and tumors < 1 cm with two or more image findings consistent with HCC with persistently increased serum alpha-fetoprotein (AFP) levels above the normal range with underlying inhibited hepatitis activity underwent liver resection. The false-positive rate was 2.2% (n = 18). Of the 18 patients, 7 patients (0.8%) were diagnosed with benign conditions (one each of hemangioma, inflammation, cortical adenoma, dysplastic nodule, angiomyolipoma, bile duct adenoma, and non-neoplastic liver parenchyme) and 11 patients (1.3%) were diagnosed with malignancies (cholangiocarcinoma [n = 6], hepatoblastoma [n = 2], and one each of lymphoepithelioma-like carcinoma, ovarian cystadenocarcinoma, and nasopharynx carcinoma metastasis). The clinical characteristics of pathologically diagnosed HCC patients were similar (P > 0.05) compared to non-HCC patients except for higher rate of history of alcoholism (P < 0.05) observed in non-HCC patients. Four of 18 non-HCC patients (22.2%) showed diagnostic discordance on the dynamic imaging study. Despite the recent progression in diagnostic imaging techniques, 2.2% of cases were false-positively diagnosed as HCC in a liver resection patient cohort; and the final diagnosis was benign disease in 0.8% of liver resection patients clinically diagnosed with HCC.

Chronic kidney disease and high eGFR according to body composition phenotype in adults with normal BMI

BACKGROUND AND AIMS

Body composition contributes to the risk of chronic kidney disease (CKD) and glomerular hyperfiltration. In adults with normal body mass index (BMI), the relationships of body composition with CKD and high estimated glomerular filtration rate (eGFR) are largely unknown.

METHODS AND RESULTS

We analyzed 10,734 adults from the Korean National Health and Nutrition Examination Survey (KNHANES), whose body mass index (BMI) was within the normal range (18.5-24.9 kg/m²). Body composition was categorized into four phenotypes (normal, sarcopenia alone, obesity alone, and sarcopenic obesity) based on appendicular lean mass index (ALMI) and total body fat percentage (TBF%) measured by dual-energy X-ray absorptiometry (DXA). We examined the relationship of CKD and high eGFR (eGFR ≥ 120 ml/min per 1.73 m²) with body composition phenotypes. Sarcopenia alone (14.3%), obesity alone (16.0%), and sarcopenic obesity (10.7%) were prevalent. The association between sarcopenia alone and eGFR was J-shaped, while that between sarcopenic obesity and eGFR was U-shaped. In multivariate logistic regression analysis compared with the normal phenotype, sarcopenic obesity had an elevated odds ratio (OR) for CKD (OR: 1.59, 95% CI: 1.16-2.19). Sarcopenia alone (OR: 1.87; 95% CI: 1.41-2.47) and sarcopenic obesity (OR: 2.37, 95% CI: 1.68-3.36) had elevated OR for high eGFR.

CONCLUSION

These findings suggest that decreased muscle mass and coexistence with excess adiposity show associations with CKD and high eGFR even in adults with normal BMI. Body composition measured by DXA could provide information on the relationship of body composition with CKD and high eGFR.

4-n-butylresorcinol enhances proteolytic degradation of tyrosinase in B16F10 melanoma cells

OBJECTIVE

4-n-butylresorcinol is a competitive inhibitor of tyrosinase and has been used as an antimelanogenic agent. However, its inhibition mechanism in intact cells is not fully understood. To elucidate the cellular mechanism, we compared in vitro and in vivo inhibitory effects of 4-n-butylresorcinol on tyrosinase activity.

METHODS

B16F10 melanoma cells were cultured in media containing α-MSH in the presence or absence of 4-n-butylresorcinol. Tyrosinase mRNA levels, protein levels and activity in B16F10 cells were compared by real-time PCR, immunostaining combined with western blot and colorimetric analysis, respectively. Melanin concentration was measured by colorimetry both in the cells and in the media. Tyrosinase glycosylation and proteolytic degradation were analysed by immunoblotting after cells were treated with Endo H/PNGase F and E64/proteasome inhibitors, respectively.

RESULTS

4-n-butylresorcinol inhibited tyrosinase activity and melanin synthesis more effectively in intact cells than in cell lysates. Western blotting and real-time RT-PCR showed that 4-n-butylresorcinol reduced protein levels, but not mRNA levels, of tyrosinase in B16F10 cells. 4-n-butylresorcinol showed no effect on the processing of tyrosinase glycosylation or on trafficking to melanosomes. However, treatment of B16F10 cells with E64 or proteasome inhibitor abrogated the 4-n-butylresorcinol-induced decrease of tyrosinase. Moreover, 4-n-butylresorcinol activated p38 MAPK, resulting in increased ubiquitination of tyrosinase.

CONCLUSION

4-n-butylresorcinol inhibits melanogenesis by enhancing proteolytic degradation of tyrosinase as well as competitive binding to tyrosinase. These findings will help to develop new, effective and safe chemicals for the treatment of hyperpigmentation disorders.

Inexplicable Outcome of Early Appearance of Hepatocellular Carcinoma in the Allograft After Deceased Donor Liver Transplantation: A Case Report

BACKGROUND

This case represents the earliest appearance of de novo HCC after liver transplantation (OLT) compared with cases of previously reported literatures.

CASE REPORT

A 45-year-old man underwent deceased donor OLT owing to decompensated liver cirrhosis. He had YMDD viral mutation and hepatitis B (HBV) and C (HCV) coinfection but no tumor was found in the liver on MRI before OLT. The donor was a healthy young female donor who was HCV and HBV negative. There was no tumor in the explant liver. After OLT, HCV RNA and hepatitis B surface antigen became undetectable with DNA-positive HBV. Nine months after OLT, a computed tomography (CT) scan was performed owing to abdominal pain, detecting a mass occupying the right lobe that depicted enhanced characteristics typical of HCC. The chest CT demonstrated metastatic lung nodules in the right basal lower lobe. Fluorescence in situ hybridization showed tumor cells from the recipient.

CONCLUSIONS

To the best of our knowledge, this is the first report of de novo hepatocellular carcinoma that has emerged within a short period of undergoing OLT.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

Liver Fibrosis Staging with MR Elastography: Comparison of Diagnostic Performance between Patients with Chronic Hepatitis B and Those with Other Etiologic Causes

Purpose To evaluate the diagnostic performance of magnetic resonance (MR) elastography in staging liver fibrosis in patients with chronic hepatitis B (CHB) and other etiologic causes. Materials and Methods This retrospective study was institutional review board-approved and the requirement for informed consent was waived. Before surgery, MR elastographic imaging was performed in 352 patients with chronic liver diseases (281 patients with CHB, 71 patients without CHB) and hepatocellular carcinomas and 64 living liver donor candidates. Liver stiffness (LS) values were measured on quantitative shear-stiffness maps of MR elastography, and the diagnostic performance of MR elastography in staging liver fibrosis was evaluated by using receiver operating characteristic curve analysis and the Obuchowski measure with the histopathologic analysis of liver fibrosis in the CHB group and in the group composed of other etiologic causes. In 120 patients (97 with CHB, 23 without CHB) and 51 donors, diagnostic performance of MR elastography was validated. Results Areas under the curve of LS values for the diagnosis of significant fibrosis (≥stage F2), severe fibrosis (≥stage F3), and cirrhosis (stage F4) in the CHB group were 0.972 (95% confidence interval: 0.948, 0.987), 0.946 (95% confidence interval: 0.916, 0.968), and 0.920 (95% confidence interval: 0.885, 0.947), respectively. Obuchowski measures were similarly high in the CHB group and in the group composed of other etiologic causes (0.970 vs 0.977). However, the estimated cutoff value for stage F4 in the group with CHB was substantially lower than in the participants with other etiologic causes: 3.67 kPa versus 4.65 kPa. In the validation study for stage F1 or greater, stage F2 or greater, stage F3 or greater, and stage F4, the Youden indexes were 0.807, 0.842, 0.806, and 0.639, respectively, in the group with CHB, and 0.783, 0.900, 1.000, and 0.917, respectively, in the group without CHB. Conclusion The diagnostic performance of MR elastography in liver fibrosis staging was similarly high in the groups with and without CHB, but the cutoff LS values for diagnosing liver cirrhosis differed between the groups with and without CHB. (©) RSNA, 2016 Online supplemental material is available for this article.

Preparation of gaseous CRMs from the primary system for (222)Rn activity measurement

For disseminating the gaseous radon standard traceable to the KRISS primary system based on the defined solid angle counting method, two kinds of radon CRM (a glass ampule type and a stainless steel cylinder type) were developed. The activity of the CRM was certified by subtracting a residual activity from the measured activity by the primary system. After certification, the ampule CRM was used to calibrate a radon-monitoring instrument and the cylinder CRM to calibrate an HPGe system. We also improved the measurement procedure of the radon primary system. In a typical radon energy spectrum, the radon peak overlaps with the polonium peak. For more reliable and accurate measurement of radon activity, a fitting method was adopted for the evaluation of radon area in the alpha energy spectrum. The result of radon activity evaluated by using the fitting method is in good agreement with that by the previous integration method.

Development of an optimized Compton suppression gamma-ray spectrometric system using Monte Carlo simulation

We have chosen to establish the Compton Suppression Spectrometer (CSS) for low activity environmental samples with a high purity germanium (HPGe) primary detector and a removable plug-in detector (NaI(Tl)) surrounded with a cylindrical annulus guard detector (NaI(Tl)). Monte Carlo simulation with PENELOPE (PENetration and Energy LOss of Positrons and Electrons) is used to determine the optimal geometry of the CSS. To verify a correlation between experiment and simulation, the energy distribution of (137)Cs and (60)Co point sources is measured and simulated for each condition. The CSS parameters are studied to determine optimal detector geometry and Compton Suppression Factor (CSF). The timing resolution of the CSS was found to be 44ns (FWHM), which is an outstanding result in the semiconductor-based gamma-ray spectrometry. All measured values of CSF agree within 5% with the values obtained from the simulation. The optimum geometry and CSF values are discussed.

New method to incorporate Type B uncertainty into least-squares procedures in radionuclide metrology

We discuss a new method to incorporate Type B uncertainty into least-squares procedures. The new method is based on an extension of the likelihood function from which a conventional least-squares function is derived. The extended likelihood function is the product of the original likelihood function with additional PDFs (Probability Density Functions) that characterize the Type B uncertainties. The PDFs are considered to describe one's incomplete knowledge on correction factors being called nuisance parameters. We use the extended likelihood function to make point and interval estimations of parameters in the basically same way as the least-squares function used in the conventional least-squares method is derived. Since the nuisance parameters are not of interest and should be prevented from appearing in the final result, we eliminate such nuisance parameters by using the profile likelihood. As an example, we present a case study for a linear regression analysis with a common component of Type B uncertainty. In this example we compare the analysis results obtained from using our procedure with those from conventional methods.

Clarification of the calculation of minimum detectable activity in low-level radioactivity measurements

We discuss a new method to determine the value of minimum detectable activity (MDA) in low-level measurements. The method is based on the Feldman-Cousins unified approach which effectively combines the construction of confidence intervals with the determination of the decision threshold and MDA. The new method requires a single probability to be pre-specified for the determination of MDA as well as decision threshold and confidence interval, in contrast with the ISO 11929 method requiring three probabilities.

Low serum magnesium is associated with coronary artery calcification in a Korean population at low risk for cardiovascular disease

BACKGROUND AND AIMS

Previous studies suggested an association between low serum magnesium levels and metabolic or cardiovascular disease. Additionally, several studies have shown that low serum magnesium is associated with vascular calcification, but there are no studies exploring its relation to coronary artery calcification (CAC). We investigated the relationship between low serum magnesium and CAC by using health examination data.

METHODS AND RESULTS

We cross-sectionally analyzed 34,553 participants who underwent coronary multi-detector computed tomography and serum magnesium level measurement in 2010-2012 as part of a health examination program at a tertiary hospital in Korea. CAC was defined as a coronary artery calcium score > 100. Participants were divided into three groups according to their serum magnesium level as follows: low < 1.9 mg/dL (n = 931), normal = 1.9-2.3 mg/dL (n = 32,341), and high > 2.3 mg/dL (n = 1281). The percentages of participants with CAC were 3.7, 1.5, and 2.3 in each group, respectively. According to multivariate analysis, low serum magnesium was associated with CAC after adjustment for age, sex, BMI, diabetes, hypertension, cardiovascular disease, systolic BP, LDL cholesterol, HDL cholesterol, eGFR, serum calcium and phosphorus, hsCRP, current smoking status, alcohol intake and vigorous exercise frequency. The odds ratio for CAC in the low serum magnesium group compared to the normal group was 2.10 (1.40-3.15, P < 0.001).

CONCLUSION

Low serum magnesium level is associated with CAC in a Korean population at low risk for cardiovascular disease. Further studies are needed to generalize this finding and to verify the causal relationship between low serum magnesium and CAC.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.