Feasibility of a deep learning artificial intelligence model for the diagnosis of pediatric ileocolic intussusception with grayscale ultrasonography

PURPOSE

This study explored the feasibility of utilizing a deep learning artificial intelligence (AI) model to detect ileocolic intussusception on grayscale ultrasound images.

METHODS

This retrospective observational study incorporated ultrasound images of children who underwent emergency ultrasonography for suspected ileocolic intussusception. After excluding video clips, Doppler images, and annotated images, 40,765 images from two tertiary hospitals were included (positive-to-negative ratio: hospital A, 2,775:35,373; hospital B, 140:2,477). Images from hospital A were split into a training set, a tuning set, and an internal test set (ITS) at a ratio of 7:1.5:1.5. Images from hospital B comprised an external test set (ETS). For each image indicating intussusception, two radiologists provided a bounding box as the ground-truth label. If intussusception was suspected in the input image, the model generated a bounding box with a confidence score (0-1) at the estimated lesion location. Average precision (AP) was used to evaluate overall model performance. The performance of practical thresholds for the modelgenerated confidence score, as determined from the ITS, was verified using the ETS.

RESULTS

The AP values for the ITS and ETS were 0.952 and 0.936, respectively. Two confidence thresholds, CTopt and CTprecision, were set at 0.557 and 0.790, respectively. For the ETS, the perimage precision and recall were 95.7% and 80.0% with CTopt, and 98.4% and 44.3% with CTprecision. For per-patient diagnosis, the sensitivity and specificity were 100.0% and 97.1% with CTopt, and 100.0% and 99.0% with CTprecision. The average number of false positives per patient was 0.04 with CTopt and 0.01 for CTprecision.

CONCLUSION

The feasibility of using an AI model to diagnose ileocolic intussusception on ultrasonography was demonstrated. However, further study involving bias-free data is warranted for robust clinical validation.

Ultra-low-dose computed tomography with deep learning reconstruction for craniosynostosis at radiation doses comparable to skull radiographs: a pilot study

BACKGROUND

Craniofacial computed tomography (CT) is the diagnostic investigation of choice for craniosynostosis, but high radiation dose remains a concern.

OBJECTIVE

To evaluate the image quality and diagnostic performance of an ultra-low-dose craniofacial CT protocol with deep learning reconstruction for diagnosis of craniosynostosis.

MATERIALS AND METHODS

All children who underwent initial craniofacial CT for suspected craniosynostosis between September 2021 and September 2022 were included in the study. The ultra-low-dose craniofacial CT protocol using 70 kVp, model-based iterative reconstruction and deep learning reconstruction techniques was compared with a routine-dose craniofacial CT protocol. Quantitative analysis of the signal-to-noise ratio and noise was performed. The 3-dimensional (D) volume-rendered images were independently evaluated by two radiologists with regard to surface coarseness, step-off artifacts and overall image quality on a 5-point scale. Sutural patency was assessed for each of six sutures. Radiation dose was compared between the two protocols.

RESULTS

Among 29 patients (15 routine-dose CT and 14 ultra-low-dose CT), 23 patients had craniosynostosis. The 3-D volume-rendered images of ultra-low-dose CT without deep learning showed decreased image quality compared to routine-dose CT. The 3-D volume-rendered images of ultra-low-dose CT with deep learning reconstruction showed higher noise level, higher surface coarseness but decreased step-off artifacts, comparable signal-to-noise ratio and overall similar image quality compared to the routine-dose CT images. Diagnostic performance for detecting craniosynostosis at the suture level showed no significant difference between ultra-low-dose CT without deep learning reconstruction, ultra-low-dose CT with deep learning reconstruction and routine-dose CT. The estimated effective radiation dose for the ultra-low-dose CT was 0.05 mSv (range, 0.03-0.06 mSv), a 95% reduction in dose over the routine-dose CT at 1.15 mSv (range, 0.54-1.74 mSv). This radiation dose is comparable to 4-view skull radiography (0.05-0.1 mSv) and lower than previously reported effective dose for craniosynostosis protocols (0.08-3.36 mSv).

CONCLUSION

In this pilot study, an ultra-low-dose CT protocol using radiation doses at a level similar to skull radiographs showed preserved diagnostic performance for craniosynostosis, but decreased image quality compared to the routine-dose CT protocol. However, by combining the ultra-low-dose CT protocol with deep learning reconstruction, image quality was improved to a level comparable to the routine-dose CT protocol, without sacrificing diagnostic performance for craniosynostosis.

Monitoring Posterior Cerebral Perfusion Changes With Dynamic Susceptibility Contrast-Enhanced Perfusion MRI After Anterior Revascularization Surgery in Pediatric Moyamoya Disease

OBJECTIVE

To determine whether dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) can be used to evaluate posterior cerebral circulation in pediatric patients with moyamoya disease (MMD) who underwent anterior revascularization.

MATERIALS AND METHODS

This study retrospectively included 73 patients with MMD who underwent DSC perfusion MRI (age, 12.2 ± 6.1 years) between January 2016 and December 2020, owing to recent-onset clinical symptoms during the follow-up period after completion of anterior revascularization. DSC perfusion images were analyzed using a dedicated software package (NordicICE; Nordic NeuroLab) for the middle cerebral artery (MCA), posterior cerebral artery (PCA), and posterior border zone between the two regions (PCA-MCA). Patients were divided into two groups; the PCA stenosis group included 30 patients with newly confirmed PCA involvement, while the no PCA stenosis group included 43 patients without PCA involvement. The relationship between DSC perfusion parameters and PCA stenosis, as well as the performance of the parameters in discriminating between groups, were analyzed.

RESULTS

In the PCA stenosis group, the mean follow-up duration was 5.3 years after anterior revascularization, and visual disturbances were a common symptom. Normalized cerebral blood volume was increased, and both the normalized time-to-peak (nTTP) and mean transit time values were significantly delayed in the PCA stenosis group compared with those in the no PCA stenosis group in the PCA and PCA-MCA border zones. TTP_PCA (odds ratio [OR] = 6.745; 95% confidence interval [CI] = 2.665-17.074; P < 0.001) and CBV_PCA-MCA (OR = 1.567; 95% CI = 1.021-2.406; P = 0.040) were independently associated with PCA stenosis. TTP_PCA showed the highest receiver operating characteristic curve area in discriminating for PCA stenosis (0.895; 95% CI = 0.803-0.986).

CONCLUSION

nTTP can be used to effectively diagnose PCA stenosis. Therefore, DSC perfusion MRI may be a valuable tool for monitoring PCA stenosis in patients with MMD.

Assessment of diagnostic accuracy and complication rates of CT-guided percutaneous core-needle biopsy for lung lesion: difference between solid and sub-solid nodules based on propensity score matching analysis

AIM

To compare the success and complication rates of computed tomography (CT)-guided percutaneous core-needle biopsy (PCNB) based on the density of lung nodules, using propensity score matching (PSM).

MATERIALS AND METHODS

This single-centre retrospective study included 1,312 PCNB cases of lung lesions, including solid (n=1,120), part-solid (n=115), and non-solid nodules (n=77), that were detected between March 2013 and March 2021. The diagnostic accuracy and complication rates of pneumothorax and pulmonary haemorrhage were analysed before PSM. To perform PSM, part-solid and non-solid nodules were combined and newly defined as sub-solid nodules. The diagnostic accuracy and complication rates of pneumothorax and pulmonary haemorrhage were then compared between solid and sub-solid nodules after PSM.

RESULTS

Among the 1,312 included cases, the success rate and incidence of pneumothorax after CT-guided PCNB for solid, part-solid, and non-solid nodules were not statistically different (p=0.080 and 0.410). However, the rates of overall pulmonary haemorrhage showed statistical differences (p<0.001), particularly between solid and part-solid nodules (p<0.001) and between solid and non-solid nodules (p<0.001). After PSM, the incidence rates of overall pulmonary haemorrhage in solid and sub-solid nodules were 8.9% (17/192) and 29.7% (44/182), respectively, showing a statistically significant difference (p<0.001).

CONCLUSION

There is increased risk of haemorrhage in CT-guided needle biopsy of sub-solid nodules compared to solid nodules. Increased emphasis should be placed on the risk of pulmonary haemorrhage when consenting these patients.

Deep Learning-Based Computed Tomography Image Standardization to Improve Generalizability of Deep Learning-Based Hepatic Segmentation

OBJECTIVE

We aimed to investigate whether image standardization using deep learning-based computed tomography (CT) image conversion would improve the performance of deep learning-based automated hepatic segmentation across various reconstruction methods.

MATERIALS AND METHODS

We collected contrast-enhanced dual-energy CT of the abdomen that was obtained using various reconstruction methods, including filtered back projection, iterative reconstruction, optimum contrast, and monoenergetic images with 40, 60, and 80 keV. A deep learning based image conversion algorithm was developed to standardize the CT images using 142 CT examinations (128 for training and 14 for tuning). A separate set of 43 CT examinations from 42 patients (mean age, 10.1 years) was used as the test data. A commercial software program (MEDIP PRO v2.0.0.0, MEDICALIP Co. Ltd.) based on 2D U-NET was used to create liver segmentation masks with liver volume. The original 80 keV images were used as the ground truth. We used the paired t-test to compare the segmentation performance in the Dice similarity coefficient (DSC) and difference ratio of the liver volume relative to the ground truth volume before and after image standardization. The concordance correlation coefficient (CCC) was used to assess the agreement between the segmented liver volume and ground-truth volume.

RESULTS

The original CT images showed variable and poor segmentation performances. The standardized images achieved significantly higher DSCs for liver segmentation than the original images (DSC [original, 5.40%-91.27%] vs. [standardized, 93.16%-96.74%], all P < 0.001). The difference ratio of liver volume also decreased significantly after image conversion (original, 9.84%-91.37% vs. standardized, 1.99%-4.41%). In all protocols, CCCs improved after image conversion (original, -0.006-0.964 vs. standardized, 0.990-0.998).

CONCLUSION

Deep learning-based CT image standardization can improve the performance of automated hepatic segmentation using CT images reconstructed using various methods. Deep learning-based CT image conversion may have the potential to improve the generalizability of the segmentation network.

Cerebral venous thrombosis after ChAdOx1 nCoV-19 vaccination: a systematic review

OBJECTIVE

To perform a systematic review of case reports or case series regarding thrombosis with thrombocytopenia syndrome (TTS) and cerebral venous thrombosis (CVT) related to ChAdOx1 nCoV-19 vaccination to address the clinical features, laboratory findings, treatment modalities, and prognosis related with CVT.

SUBJECTS AND METHODS

We included 64 TTS patients from 19 articles, 6 case series and 13 case reports, in which thrombosis occurred after the first dose of ChAdOx1 nCoV-19 vaccination published up to 30 June 2021 in Embase, ePubs, Medline/PubMed, Scopus, and Web of Science databases.

RESULTS

Of the 64 TTS patients, 38 (59.3%) had CVT. Patients with CVT were younger (median 36.5 vs. 52.5 years, p<0.001), had lower fibrinogen levels (130 vs. 245 mg/dL, p=0.008), had more frequent history of intracerebral hemorrhage (ICH), and had higher mortality rate (48.6% vs. 19.2%, p=0.020) than that of patients without CVT. In multivariable analysis, the possibility of presence of CVT was higher in younger age groups [odd ratio (OR): 0.91, 95% confidence interval (CI): (0.86-0.97, p<0.001)] and those with accompanying intracerebral hemorrhage (ICH) (OR: 13.60, 95% CI (1.28-144.12, p=0.045).

CONCLUSIONS

Our study demonstrated that CVT related to ChAdOx1 nCoV-19 vaccination was associated with younger age, low levels of fibrinogen, presence of ICH and more frequent mortality compared to those of non-CVT. If TTS occurs after ChAdOx1 nCoV-19 vaccination, the presence of CVT in patients with young age or ICH should be considered.

Contrast-enhanced ultrasound for the diagnosis of acute pyelonephritis in pediatric patients with urinary tract infection: A feasibility study

PURPOSE

This study aimed to assess the feasibility of contrast-enhanced ultrasound (CEUS) for the diagnosis of acute pyelonephritis (APN) in pediatric patients with febrile urinary tract infection (UTI).

MATERIALS AND METHODS

Between March 2019 and January 2021, study participants with suspected UTI were assessed for APN using ultrasound. Parenchymal echogenicity changes, renal pelvis dilatation, and the presence of a focal suspected lesion were assessed using conventional grayscale ultrasound. The presence and location of a decreased perfusion area were evaluated using color Doppler ultrasound (CDUS) and CEUS. Agreement between each ultrasound examination and a 99mTc‒dimercaptosuccinic acid (DMSA) scan was assessed using the κ value, and the most visible period of the lesion was evaluated using CEUS.

RESULTS

This study enrolled 21 participants (median age, 8.0 months; range, 2.0-61.0 months) with isolated urinary tract pathogens. Five increased parenchymal echotextures (11.9%) and 14 renal pelvic dilatations (33.3%) were confirmed, but no focal lesions were detected on the grayscale images. CDUS and CEUS showed decreased local perfusion suggestive of APN in two and five kidneys, respectively. DMSA scan showed substantial agreement with CEUS findings (κ = 0.80, P = 0.010), but other grayscale and CDUS findings did not agree with DMSA scan results (P > 0.05). All lesions were best observed in the late parenchymal phase on CEUS.

CONCLUSION

CEUS can reveal renal perfusion defects in pediatric patients with suspected APN without radiation exposure or sedation; therefore, CEUS may be a feasible and valuable diagnostic technique.

Usefulness of two-dimensional shear wave elastography in diagnosing hepatic veno-occlusive disease in pediatric patients undergoing hematopoietic stem cell transplantation

PURPOSE

This study aimed to evaluate the usefulness of two-dimensional shear wave elastography (2D-SWE) in diagnosing hepatic veno-occlusive disease (VOD) in pediatric patients.

METHODS

This study retrospectively included pediatric patients who underwent hematopoietic stem cell transplantation (HSCT) between November 2019 and January 2021. All 34 patients (8.7±5.0 years) were examined using 2D-SWE for an initial diagnosis. A subgroup analysis was performed using the data from follow-up examinations of patients diagnosed with VOD. The characteristics of the initial VOD diagnosis were compared with the longitudinal changes observed in VOD patients who underwent multiple ultrasound examinations.

RESULTS

In total, 19 patients were diagnosed with VOD at 17.6±9.4 days after HSCT. All VOD patients showed hepatomegaly, ascites, and gallbladder wall thickening. Liver stiffness was higher in VOD patients than in non-VOD patients (12.4±1.1 vs. 6.3±0.8 kPa, P<0.001). Liver stiffness values above 7.2 kPa showed 84.2% sensitivity and 93.3% specificity in distinguishing VOD from non-VOD (area under the curve, 0.925; 95% confidence interval, 0.780 to 0.987; P<0.001). A subgroup analysis of 11 patients showed a linear decrease in liver stiffness values after VOD diagnosis with treatment (first, second, and third follow-ups; 13.5±1.7, 11.3±1.4, and 9.5±0.8 kPa, respectively), but without statistical significance in the pairwise analysis.

CONCLUSION

Liver stiffness measured using 2D-SWE increased in pediatric patients who develop VOD after HSCT. Therefore, liver stiffness can be a predictive and quantitative parameter for diagnosing VOD.

Case mistaken for leukemia after mRNA COVID-19 vaccine administration: A case report

BACKGROUND

Following the global outbreak of coronavirus disease 2019 (COVID-19), unlike other vaccines, COVID-19 vaccines were developed and commercialized in a relatively short period of time. The large-scale administration of this vaccine in a short time-period led to various unexpected side effects, including severe cytopenia and thrombosis with thrombocytopenia syndrome. Despite many reports on adverse reactions, vaccination was necessary to prevent the spread of COVID-19; thus, it is essential to understand and discuss various cases of adverse reactions after vaccination.

CASE SUMMARY

A 77-year-old woman was administered the second dose of Pfizer mRNA COVID-19 vaccine. After vaccination she experienced fever, myalgia, and weakness. Antibiotics were subsequently administered for several days, but there was no improvement in the symptoms. The patient showed severe thrombocytopenia and leukocytosis. Thoracic and abdominopelvic computed tomography showed no infection related findings, but splenomegaly and cirrhotic liver features were observed. A large number of immature cells were observed in the peripheral blood smear; thus, bone marrow examination was performed for acute leukemia. However, there were no abnormalities. The patient recovered after administration of hepatotoxins and transfusion treatment for cytopenia and was diagnosed with an adverse reaction to COVID-19 vaccination.

CONCLUSION

Adverse reactions of vaccination could be mistaken for hematologic malignancies including leukemia. We report a patient with leukocytosis following COVID-19 vaccination.

Development and evaluation of deep-learning measurement of leg length discrepancy: bilateral iliac crest height difference measurement

BACKGROUND

Leg length discrepancy (LLD) is a common problem that can cause long-term musculoskeletal problems. However, measuring LLD on radiography is time-consuming and labor intensive, despite being a simple task.

OBJECTIVE

To develop and evaluate a deep-learning algorithm for measurement of LLD on radiographs.

MATERIALS AND METHODS

In this Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study, radiographs were obtained to develop a deep-learning algorithm. The algorithm developed with two U-Net models measures LLD using the difference between the bilateral iliac crest heights. For performance evaluation of the algorithm, 300 different radiographs were collected and LLD was measured by two radiologists, the algorithm alone and the model-assisting method. Statistical analysis was performed to compare the measurement differences with the measurement results of an experienced radiologist considered as the ground truth. The time spent on each measurement was then compared.

RESULTS

Of the 300 cases, the deep-learning model successfully delineated both iliac crests in 284. All human measurements, the deep-learning model and the model-assisting method, showed a significant correlation with ground truth measurements, while Pearson correlation coefficients and interclass correlations (ICCs) decreased in the order listed. (Pearson correlation coefficients ranged from 0.880 to 0.996 and ICCs ranged from 0.914 to 0.997.) The mean absolute errors of the human measurement, deep-learning-assisting model and deep-learning-alone model were 0.7 ± 0.6 mm, 1.1 ± 1.1 mm and 2.3 ± 5.2 mm, respectively. The reading time was 7 h and 12 min on average for human reading, while the deep-learning measurement took 7 min and 26 s. The radiologist took 74 min to complete measurements in the deep-learning mode.

CONCLUSION

A deep-learning U-Net model measuring the iliac crest height difference was possible on teleroentgenograms in children. LLD measurements assisted by the deep-learning algorithm saved time and labor while producing comparable results with human measurements.

[Jaundice in Young Children]

Jaundice in children have various etiologies. Among them, physiological jaundice is a very common disease observed in more than half of full-term neonates. When jaundice persists or develops after 2 weeks of age, the total/direct bilirubin is measured in consideration of the possibility of cholestasis. In case of cholestasis, imaging studies differentiate biliary atresia and other disorders of the extrahepatic bile ducts. In this review, we briefly presented the major differential diseases of cholestasis in children and introduced diagnostic imaging techniques, including normal findings.

Non-secretory multiple myeloma expressed as multiple extramedullary plasmacytoma with an endobronchial lesion mimicking metastatic cancer: A case report

BACKGROUND

Non-secretory multiple myeloma (MM) is a rare condition that accounts for only 3% of MM cases and is defined by normal serum and urine immunofixation and a normal serum free light chain ratio. Non-secretory MM with multiple extramedullary plasmacytomas derived from endobronchial lesions is extremely rare and can be misdiagnosed as metastasis of solid cancer.

CASE SUMMARY

A 36-year-old man presented with progressive facial swelling and nasal congestion with cough. Various imaging studies revealed an endobronchial mass in the left bronchus and a large left maxillary mass with multiple destructive bone metastatic lesions. He initially presented with lung cancer and multiple metastases. However, pathologic reports showed multiple extramedullary plasmacytomas in the left maxilla and the left bronchus. There was no change in the serum and urine monoclonal protein levels, and no abnormalities were observed in laboratory examinations, including hemoglobin, calcium, and creatinine levels. The bone marrow was hypercellular, with 13.49% plasma cells. The patient was diagnosed with non-secretory MM expressed as multiple extramedullary plasmacytomas with endobronchial lesions in a rare location. Radiation therapy for symptomatic lesions with high-dose dexamethasone was started, and the size of the left maxillary sinus lesion dramatically decreased. In the future, chemotherapy will be administered to control lesions in other areas.

CONCLUSION

We present a rare case of non-secretory MM with multiple extramedullary plasmacytoma with an endobronchial lesion.

Automated segmentation of whole-body CT images for body composition analysis in pediatric patients using a deep neural network

OBJECTIVES

To develop an automatic segmentation algorithm using a deep neural network with transfer learning applicable to whole-body PET-CT images in children.

METHODS

For model development, we utilized transfer learning with a pre-trained model based on adult patients. We used CT images of 31 pediatric patients under 19 years of age (mean age, 9.6 years) who underwent PET-CT from institution #1 for transfer learning. Two radiologists manually labeled the skin, bone, muscle, abdominal visceral fat, subcutaneous fat, internal organs, and central nervous system in each CT slice and used these as references. For external validation, we collected 14 pediatric PET/CT scans from institution #2 (mean age, 9.1 years). The Dice similarity coefficients (DSCs), sensitivities, and precision were compared between the algorithms before and after transfer learning. In addition, we evaluated segmentation performance according to sex, age (≤ 8 vs. > 8 years), and body mass index (BMI, ≤ 20 vs. > 20 kg/m²).

RESULTS

The algorithm after transfer learning showed better performance than the algorithm before transfer learning for all body compositions (p < 0.001). The average DSC, sensitivity, and precision of each algorithm before and after transfer learning were 98.23% and 99.28%, 98.16% and 99.28%, and 98.29% and 99.28%, respectively. The segmentation performance of the algorithm was generally not affected by age, sex, or BMI, except for precision in the body muscle compartment.

CONCLUSION

The developed model with transfer learning enabled accurate and fully automated segmentation of multiple tissues on whole-body CT scans in children.

KEY POINTS

• We utilized transfer learning with a pre-trained segmentation algorithm for adult to develop an algorithm for automated segmentation of pediatric whole-body CT. • This algorithm showed excellent performance and was not affected by sex, age, or body mass index, except for precision in body muscle.

Transradial Cerebral Angiography: Is it Feasible and Safe for Children?

PURPOSE

To investigate the feasibility and safety of transradial cerebral angiography (TRCA) in comparison to transfemoral cerebral angiography (TFCA) in the pediatric population.

MATERIALS AND METHODS

We retrospectively reviewed pediatric patients who underwent TRCA between January 2019 and July 2020. Patients with TFCA experience were examined. Pre- and post-procedural Doppler ultrasonography was performed to evaluate TRCA complications. To evaluate differences in radiation exposure between TRCA and TFCA, we investigated the radiation dose, dose area product (DAP), fluoroscopy time, and examination time.

RESULTS

Thirty-five patients (mean age, 13.8 years; 22 male) underwent TRCA, with 18 (mean age, 13.0 years; 10 male) experiencing TFCA. TRCA was successful in all cases without technical failure. Radiation exposure including radiation dose and DAP were significantly higher in the TRCA group (474.1 mGy and 8299.6 μGy m²) compared with the TFCA group (347.8 mGy and 6342.0 μGy m²). Fluoroscopy time and total examination time were significantly longer (145.1% and 32.6%) in TRCA (15.2 and 38.6 min) group compared with the TFCA group (6.2 and 29.1 min). Among the 26 patients who underwent post-procedural Doppler ultrasonography, five (19.2%) had complications after TRCA. Two (7.7%) patients showed radial artery stenosis, two (7.7%) had hematoma at the puncture site, and one (3.8%) showed thrombotic occlusion.

CONCLUSION

Although TRCA is a technically feasible and safe method in pediatric patients, high radiation exposure to TFCA must be considered. Therefore, it should be considered as an alternative method in those with unfavorable clinical situations for performing TFCA.

LEVEL OF EVIDENCE

Level 4, Case Series.

Agricultural nitrogen and phosphorus balances of Korea and Japan: Highest nutrient surplus among OECD member countries

Excessive nutrient balance is a very crucial issue for environmental hazards. The constant addition of high-amounts of nutrient sources in agricultural production generates negative environmental conditions in Korea and Japan yet to be resolved. Therefore, it is obligatory to comprehend the nutrient (nitrogen (N) and phosphorus (P)) balance that is assessed by the difference between nutrient input and output in the soil surface in Korea and Japan. Among 34 Economic Co-operation and Development (OECD) countries, Korea and Japan had the highest N and P balances and thus both countries are primarily responsible for severe environmental pollution via nutrient release. The cultivable land area in both countries has constantly decreased during 1990-2017 at approximately 20 and 15% in Korea and Japan, respectively. Even N and P use efficiency sharply decreased with increasing N and P balance in both targeted countries. Japanese P balance, Korean N and P balances were decreased after the mid-1990s whereas, Japanese N balance almost unchanged for the last 28 years. Unlike chemical fertilizer input, Korean manure input level significantly increased from 78 kg N ha^-1 in 1990 to 157 kg N ha^-1 in 2017. Japanese manure input level was higher than that of chemical fertilizer without any big change for the last 28 years. The lion share of high N and P balance in both countries could generate from manure inputs, therefore, the number of livestock and their produced debris need to be used with more cautious for the reduction of national N and P surpluses at a benchmark level. These findings ensure to make a more environment friendly policy that can further reduce nutrient balance as well as improve soil health.

Korean Society of Thyroid Radiology Guidelines for the Management of Pediatric Thyroid Nodules: Suitability and Risk Factors

Background: The guideline for managing pediatric thyroid nodules has not been established. We investigated the appropriateness of the Korean Society of Thyroid Radiology (KSThR) guidelines and the need to consider risk factors for managing pediatric thyroid nodules. Methods: From August 2007 to February 2020, a database of thyroid nodules in patients younger than 19 years who underwent fine-needle aspiration (FNA) was analyzed. Two radiologists retrospectively reviewed ultrasound images to characterize the nodules according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) criteria. Thyroid nodules were divided into benign and malignant nodules. Clinical risk factors were identified, including familial thyroid cancer, history of radiation therapy, and underlying thyroiditis. According to the K-TIRADS categories and the presence of risk factors, malignancy rates were calculated. We compared the diagnostic performance of the original KSThR guidelines and newly suggested criteria for FNA derived by simulation tests with variable size cutoffs in the total study population, a group with risk factors, and a group without risk factors. Results: A total of 107 patients (mean age, 13.9 years; range, 4-18 years; 83 females; 50 patients with risk factors) with 133 nodules (71 benign and 62 malignant) were included. The malignancy rate of thyroid nodules was higher in the group with risk factors (64.0%) than in the group without risk factors (43.9%; p = 0.037). Compared with the KSThR guideline (≥1.0 cm for K-TIRADS 4 and 5), the accuracy was higher (62.4% vs. 56.4%) and the unnecessary biopsy rate was lower (44.0% vs. 47.4%) when the new criteria (≥0.6 cm for K-TIRADS 4 and ≥0.5 cm for K-TIRADS 5) were used in the total study population. In particular, in the group with risk factors, the newly suggested size criteria had a much higher accuracy (73.1% vs. 59.7%) and lower unnecessary biopsy rate (30.4% vs. 35.5%) than the KSThR guideline. Conclusions: For the management of thyroid nodules in children, it is necessary to consider risk factors and adjust the criteria values for FNA. FNA should be considered in children with risk factors for thyroid cancer even if thyroid nodules are small.

Shear-wave elastography for the assessment of testicular involvement of hematologic malignancies in children and young adults: a feasibility study

Purpose

This study aimed to assess the feasibility of shear-wave elastography (SWE) for assessing the testicular involvement of hematologic malignancies in children and young adults.

Methods

Eight patients (mean age, 11.0 years; range, 0.8 to 20 years) with biopsy-confirmed testicular involvement of hematologic malignancy between January 2018 and December 2020 were retrospectively evaluated. Multiparametric ultrasound examinations, including grayscale, color Doppler ultrasonography (CDUS), and SWE, were performed. Stiffness was measured in the involved testicular area and contralateral normal parenchyma. If there was bilateral testicular involvement, the stiffness of the involved area and the adjacent normal echoic parenchyma was measured on one testis. The Mann-Whitney U test was used to compare stiffness values.

Results

On grayscale, the testicular lesions were noted as a solitary mass in one patient, multiple lesions in four patients, and diffuse involvement in three patients. On CDUS and SWE, all patients demonstrated increased vascularity, and the stiffness of the involved area was higher than the values of normal parenchyma (the involved area vs. normal parenchyma, 11.6 kPa [3.9-20.2 kPa] vs. 2.9 kPa [1.1-3.7 kPa], P=0.003). The ratio of stiffness between the involved area and normal parenchyma was 3.4, ranging from 1.9 to 5.1. One patient showed decreased stiffness on follow-up SWE after treatment (affected testis vs. normal testis: initial, 13.8 vs. 3.2 kPa; 1 year later, 2.2 vs. 2.4 kPa).

Conclusion

Increased testicular stiffness on SWE in children and young adults with hematologic malignancies suggests the possibility of testicular involvement.

Monitoring Cerebral Perfusion Changes Using Arterial Spin-Labeling Perfusion MRI after Indirect Revascularization in Children with Moyamoya Disease

OBJECTIVE

To assess the role of arterial spin-labeling (ASL) perfusion MRI in identifying cerebral perfusion changes after indirect revascularization in children with moyamoya disease.

MATERIALS AND METHODS

We included pre- and postoperative perfusion MRI data of 30 children with moyamoya disease (13 boys and 17 girls; mean age ± standard deviation, 6.3 ± 3.0 years) who underwent indirect revascularization between June 2016 and August 2017. Relative cerebral blood flow (rCBF) and qualitative perfusion scores for arterial transit time (ATT) effects were evaluated in the middle cerebral artery (MCA) territory on ASL perfusion MRI. The rCBF and relative time-to-peak (rTTP) values were also measured using dynamic susceptibility contrast (DSC) perfusion MRI. Each perfusion change on ASL and DSC perfusion MRI was analyzed using the paired t test. We analyzed the correlation between perfusion changes on ASL and DSC images using Spearman's correlation coefficient.

RESULTS

The ASL rCBF values improved at both the ganglionic and supraganglionic levels of the MCA territory after surgery (p = 0.040 and p = 0.003, respectively). The ATT perfusion scores also improved at both levels (p < 0.001 and p < 0.001, respectively). The rCBF and rTTP values on DSC MRI showed significant improvement at both levels of the MCA territory of the operated side (all p < 0.05). There was no significant correlation between the improvements in rCBF values on the two perfusion images (r = 0.195, p = 0.303); however, there was a correlation between the change in perfusion scores on ASL and rTTP on DSC MRI (r = 0.701, p < 0.001).

CONCLUSION

Recognizing the effects of ATT on ASL perfusion MRI may help monitor cerebral perfusion changes and complement quantitative rCBF assessment using ASL perfusion MRI in patients with moyamoya disease after indirect revascularization.

The usefulness of noninvasive liver stiffness assessment using shear-wave elastography for predicting liver fibrosis in children

BACKGROUND

Pediatric patients with liver disease require noninvasive monitoring to evaluate the risk of fibrosis progression. This study aimed to identify the significant factors affecting liver stiffness values using two-dimensional shear-wave elastography (2D-SWE), and determine whether liver stiffness can predict the fibrosis stage of various childhood liver diseases.

METHODS

This study included 30 children (22 boys and 8 girls; mean age, 5.1 ± 6.1 years; range, 7 days-17.9 years) who had undergone biochemical evaluation, 2D-SWE examination, histopathologic analysis of fibrosis grade (F0 to F3), assessment of necroinflammatory activity, and steatosis grading between August 2016 and March 2020. The liver stiffness from 2D-SWE was compared between fibrosis stages using Kruskal-Wallis analysis. Factors that significantly affected liver stiffness were evaluated using univariate and multivariate linear regression analyses. The diagnostic performance was determined from the area under the receiver operating curve (AUC) values of 2D-SWE liver stiffness.

RESULTS

Liver stiffness at the F0-1, F2, and F3 stages were 7.9, 13.2, and 21.7 kPa, respectively (P < 0.001). Both fibrosis stage and necroinflammatory grade were significantly associated with liver stiffness (P < 0.001 and P = 0.021, respectively). However, in patients with alanine aminotransferase (ALT) levels below 200 IU/L, the only factor affecting liver stiffness was fibrosis stage (P = 0.030). The liver stiffness value could distinguish significant fibrosis (≥ F2) with an AUC of 0.950 (cutoff value, 11.3 kPa) and severe fibrosis (F3 stage) with an AUC of 0.924 (cutoff value, 18.1 kPa). The 2D-SWE values for differentiating significant fibrosis were 10.5 kPa (≥ F2) and 18.1 kPa (F3) in patients with ALT levels below 200 IU/L.

CONCLUSION

The liver stiffness values on 2D-SWE can be affected by both fibrosis and necroinflammatory grade and can provide excellent diagnostic performance in evaluating the fibrosis stage in various pediatric liver diseases. However, clinicians should be mindful of potential confounders, such as necroinflammatory activity or transaminase level, when performing 2D-SWE measurements for liver fibrosis staging.

Diagnostic Performance of a New Convolutional Neural Network Algorithm for Detecting Developmental Dysplasia of the Hip on Anteroposterior Radiographs

OBJECTIVE

To evaluate the diagnostic performance of a deep learning algorithm for the automated detection of developmental dysplasia of the hip (DDH) on anteroposterior (AP) radiographs.

MATERIALS AND METHODS

Of 2601 hip AP radiographs, 5076 cropped unilateral hip joint images were used to construct a dataset that was further divided into training (80%), validation (10%), or test sets (10%). Three radiologists were asked to label the hip images as normal or DDH. To investigate the diagnostic performance of the deep learning algorithm, we calculated the receiver operating characteristics (ROC), precision-recall curve (PRC) plots, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) and compared them with the performance of radiologists with different levels of experience.

RESULTS

The area under the ROC plot generated by the deep learning algorithm and radiologists was 0.988 and 0.988-0.919, respectively. The area under the PRC plot generated by the deep learning algorithm and radiologists was 0.973 and 0.618-0.958, respectively. The sensitivity, specificity, PPV, and NPV of the proposed deep learning algorithm were 98.0, 98.1, 84.5, and 99.8%, respectively. There was no significant difference in the diagnosis of DDH by the algorithm and the radiologist with experience in pediatric radiology (p = 0.180). However, the proposed model showed higher sensitivity, specificity, and PPV, compared to the radiologist without experience in pediatric radiology (p < 0.001).

CONCLUSION

The proposed deep learning algorithm provided an accurate diagnosis of DDH on hip radiographs, which was comparable to the diagnosis by an experienced radiologist.

Noise reduction approach in pediatric abdominal CT combining deep learning and dual-energy technique

OBJECTIVES

To evaluate the image quality of low iodine concentration, dual-energy CT (DECT) combined with a deep learning-based noise reduction technique for pediatric abdominal CT, compared with standard iodine concentration single-energy polychromatic CT (SECT).

METHODS

From December 2016 to May 2017, DECT with 300 mg•I/mL contrast medium was performed in 29 pediatric patients (17 boys, 12 girls; age, 2-19 years). The DECT images were reconstructed using a noise-optimized virtual monoenergetic reconstruction image (VMI) with and without a deep learning method. SECT images with 350 mg•I/mL contrast medium, performed within the last 3 months before the DECT, served as reference images. The quantitative and qualitative parameters were compared using paired t tests and Wilcoxon signed-rank tests, and the differences in radiation dose and total iodine administration were assessed.

RESULTS

The linearly blended DECT showed lower attenuation and higher noise than SECT. The 60-keV VMI showed an increase in attenuation and higher noise than SECT. The combined 60-keV VMI plus deep learning images showed low noise, no difference in contrast-to-noise ratios, and overall image quality or diagnostic image quality, but showed a higher signal-to-noise ratio in the liver and lower enhancement of lesions than SECT. The overall image and diagnostic quality of lesions were maintained on the combined noise reduction approach. The CT dose index volume and total iodine administration in DECT were respectively 19.6% and 14.3% lower than those in SECT.

CONCLUSION

Low iodine concentration DECT, combined with deep learning in pediatric abdominal CT, can maintain image quality while reducing the radiation dose and iodine load, compared with standard SECT.

KEY POINTS

• An image noise reduction approach combining deep learning and noise-optimized virtual monoenergetic image reconstruction can maintain image quality while reducing radiation dose and iodine load. • The 60-keV virtual monoenergetic image reconstruction plus deep learning images showed low noise, no difference in contrast-to-noise ratio, and overall image quality, but showed a higher signal-to-noise ratio in the liver and a lower enhancement of lesion than single-energy polychromatic CT. • This combination could offer a 19.6% reduction in radiation dose and a 14.3% reduction in iodine load, in comparison with a control group that underwent single-energy polychromatic CT with the standard protocol.

Providing essential clinical care for non-COVID-19 patients in a Seoul metropolitan acute care hospital amidst ongoing treatment of COVID-19 patients

We assessed infection control efforts by comparing data collected over 20 weeks during a pandemic under a dual-track healthcare system. A decline in non-COVID-19 patients visiting the emergency department by 37.6% (P<0.01) was observed since admitting COVID-19 cases. However, patients with acute myocardial infarction (AMI), stroke, severe trauma and acute appendicitis presenting for emergency care did not decrease. Door-to-balloon time (34.3 (± 11.3) min vs 22.7 (± 8.3) min) for AMI improved significantly (P<0.01) while door-to-needle time (55.7 (± 23.9) min vs 54.0 (± 18.0) min) in stroke management remained steady (P=0.80). Simultaneously, time-sensitive care involving other clinical services, including patients requiring chemotherapy, radiation therapy and haemodialysis did not change.

Incidence and Risk Factors of Nausea and Vomiting after Exposure to Low-Osmolality Iodinated Contrast Media in Children: A Focus on Preparative Fasting

Objective

To evaluate the incidence and risk factors of emetic complications associated with the intravenous administration of low-osmolality iodinated contrast media (ICM) in children undergoing computed tomography (CT).

Materials and Methods

All children who underwent contrast-enhanced CT between April 2017 and July 2019 were included. Pediatric patients were instructed on the preparative dietary protocol at our institution. Experienced nurses in the radiology department monitored the children during the CT scans and recorded any emetic complications in their electronic medical records. These data were used to calculate the incidence of emetic complications. Various patient factors and technical factors, including fasting duration, the type and volume of ICM, and ongoing chemotherapy, were evaluated to identify risk factors for emetic complications using univariate and multivariate logistic regression analyses.

Results

Among the 864 children (mean age, 8.4 ± 5.7 years) evaluated, 18 (2.1%) experienced emetic complications (6 experienced nausea only and 12 experienced nausea and vomiting). None of the children developed aspiration pneumonia. The mean fasting duration of patients with emesis was 7.9 ± 5.7 hours (range, 3–21 hours), whereas that of patients without nausea was 8.7 ± 5.7 hours (range, 0–24 hours). Fasting duration was not associated with the development of nausea and vomiting (p = 0.634). Multivariate logistic regression analysis revealed that ongoing chemotherapy (odds ratio [OR] = 4.323; 95% confidence interval [CI] = 1.430–13.064; p = 0.009), iomeprol use (OR = 7.219; 95% CI = 1.442–36.146; p = 0.016), and iohexol use (OR = 5.241; 95% CI = 1.350–20.346; p = 0.017) were independent risk factors for emetic complications.

Conclusion

Only a small proportion (2.1%) of children experienced nausea or vomiting after exposure to low-osmolality ICM. Many children underwent excessive fasting; however, fasting duration was not associated with nausea and vomiting. Moreover, ongoing chemotherapy and the use of iomeprol or iohexol were identified as potential risk factors for emetic complications in children.

Intraobserver and interobserver reliability in sonographic size measurements of gallbladder polyps

OBJECTIVES

To evaluate the intraobserver and interobserver reliability of gallbladder polyp measurements using transabdominal US and the factors that affect reliability.

METHODS

From November 2017 to February 2018, two radiologists measured the maximum diameter of 91 gallbladder polyps using transabdominal US. Intraobserver and interobserver agreement were determined using 95% Bland-Altman limits of agreement and intraclass correlation coefficients (ICCs). The effects of image settings, polyp location, and polyp size were evaluated by comparing ICCs using z tests.

RESULTS

The intraobserver agreement rates were 0.960 (95% confidence interval [CI], 0.939-0.973) for observer 1 and 0.962 (95% CI, 0.943-0.975) for observer 2. The ICCs between the two observers were 0.963 (95% CI, 0.926-0.979) for the first measurement and 0.973 (95% CI, 0.950-0.984) for the second measurement. The 95% limits of agreement on repeated measurements were 22.3-25.2% of the mean, and those between the two observers were 25.5-34.2% of the mean. ICCs for large polyps (≥ 5 mm) were significantly higher than those for small polyps (< 5 mm). There were no significant differences in the ICCs between image settings and polyp location.

CONCLUSIONS

Polyp size measurements using transabdominal US are highly repeatable and reproducible. Polyp size significantly affects the reliability of measurement. Diameter changes of approximately less than 25% may fall within the measurement error; this should be considered while interpreting the change in size during follow-up US, especially for small polyps.

KEY POINTS

• Gallbladder polyp size measurement using transabdominal US is highly repeatable and reproducible. • Diameter changes of approximately less than 25% should be interpreted carefully, especially in small polyps.

Evaluation of frequency-selective non-linear blending technique on brain CT in postoperative children with Moyamoya disease

OBJECTIVE

To evaluate whether a frequency-selective non-linear blending (BC) technique can improve tissue contrast and infarct detection on non-enhanced brain CT (NECT) in postoperative Moyamoya (MMD) patients.

MATERIALS AND METHODS

From January 2010 to December 2017, 33 children (13boys and 20girls; mean age 9.1±3.4 years) with MMD postoperatively underwent NECT followed by diffusion MRI. We compared the contrast-to-noise ratio (CNR) between gray matter (GM) and white matter (WM) in NECT and BC images and the CNR between the infarct lesion and adjacent normal-appearing brain in NECT and BC images using a paired t-test. We assessed image noise, GM-WM differentiation, artifacts, and overall quality using a Wilcoxon signed rank test. A McNemar two-tailed test was conducted to compare the diagnostic accuracy of infarct detection.

RESULTS

The CNR between GM and WM and the CNR of the infarct was better in BC images than in NECT images (3.9±1.0 vs. 1.8±0.6, P<0.001 and 3.6±0.3 vs. 1.9±0.2, P<0.001), with no difference in overall image quality observed. The sensitivity and specificity of infarct detection were 55.0% and 76.9% using NECT, and 70.0% and 69.2% using BC technique. The diagnostic accuracy of NECT and BC technique was 63.6% (21/33) and 69.7% (23/33), respectively.

CONCLUSION

This study showed that the BC technique improved CNR and maintained image quality. This technique may also be used to identify ischemic brain changes in postoperative MMD patients by improving the CNR of the infarct lesion.

A Novel Collateral Imaging Method Derived from Time-Resolved Dynamic Contrast-Enhanced MR Angiography in Acute Ischemic Stroke: A Pilot Study

BACKGROUND AND PURPOSE

Assessment of the collateral status has been emphasized for appropriate treatment decisions in patients with acute ischemic stroke. The purpose of this study was to introduce a multiphase MRA collateral imaging method (collateral map) derived from time-resolved dynamic contrast-enhanced MRA and to verify the value of the multiphase MRA collateral map in acute ischemic stroke by comparing it with the multiphase collateral imaging method (MRP collateral map) derived from dynamic susceptibility contrast-enhanced MR perfusion.

MATERIALS AND METHODS

From a prospectively maintained registry of acute ischemic stroke, MR imaging data of patients with acute ischemic stroke caused by steno-occlusive lesions of the unilateral ICA and/or the M1 segment of the MCA were analyzed. We generated collateral maps using dynamic signals from dynamic contrast-enhanced MRA and DSC-MRP using a Matlab-based in-house program and graded the collateral scores of the multiphase MRA collateral map and the MRP collateral map independently. Interobserver reliabilities and intermethod agreement between both collateral maps for collateral grading were tested.

RESULTS

Seventy-one paired multiphase MRA and MRP collateral maps from 67 patients were analyzed. The interobserver reliabilities for collateral grading using multiphase MRA or MRP collateral maps were excellent (weighted κ = 0.964 and 0.956, respectively). The agreement between both collateral maps was also excellent (weighted κ = 0.884; 95% confidence interval, 0.819-0.949).

CONCLUSIONS

We demonstrated that the dynamic signals of dynamic contrast-enhanced MRA could be used to generate multiphase collateral images and showed the possibility of the multiphase MRA collateral map as a useful collateral imaging method in acute ischemic stroke.

Abstract P6-09-09: Analysis of serial circulating tumor cell count during neoadjuvant systemic therapy in breast cancer patients

Background: We aimed to evaluate the clinical implication of circulating tumor cell (CTC) counts in correlation with prognosis and radiologic/pathologic response to therapy in locally advanced breast cancer patients undergoing preoperative systemic therapy.

Methods: From Feb 2014 to May 2017, 207 patients without distant metastasis were prospectively enrolled from AMC. CTC counts were analyzed before-during-after the therapy. CTC isolation was performed using a SMART BIOPSY™ SYSTEM Isolation kit (Cytogen, Inc., Seoul, Korea). Recurrence-free and overall survival was analyzed according to CTC counts.

Result: The mean follow-up period was 22.46 months and mean age was 46.48 years. One or more CTC was identified in 132 of 203 patients(65.0%) before NST, in 135 of 186 patients(72.0%) during NST and 103 of 171 patients(60.2%) after NST. Initial tumor burden at diagnosis -tumor size, lymph node metastasis- was not correlated with CTC positivity. Overall, CTC count ((≥1 CTC, ≥2 CTCs, and ≥5 CTCs) was not correlated with response to therapy. Using RECIST criteria, 86.5% (179/204) were responders (complete, partial response, CR/PR) and 12.1% (25/204) were non-responders (stable, progressive disease, SD/PD). 14.5% (30/207) showed a pathologic complete response (pCR), yet no association was found between CTC count/changes and radiologic/pathologic response to therapy. Also, CTC count was not correlated with prognosis among the whole population. However, HR+ tumors, CTC detection before NST was significantly associated with treatment response by RECIST criteria (responder vs. non-responder) (p=0.003, p=0.017 and p=0.023, respectively).

Conclusions: Our findings support limited value of CTC count for locally advanced breast cancers undergoing neoadjuvant systemic therapy.

Citation Format: Gwark S-C, Kim J, Kim YH, Kim MS, Park JY, Lee SB, Sohn G, Chung IY, Ko BS, Kim HJ, Lee JW, Son BH, Ahn SH. Analysis of serial circulating tumor cell count during neoadjuvant systemic therapy in breast cancer patients [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 P6-09-09.

Abstract P1-02-04: Is asymptomatic surveillance after standard treatment beneficial? : A 10yr-survival analysis of recurrent breast cancer patients by detection method of recurrence

Surveillance of recurrence after standard treatment of breast cancer (BC) for early detection and it's impact on overall survival are known to differ depending on recurrent site. Current guideline recommends asymptomatic surveillance to only detect loco-regional recurrences. As the evidences depend on historical randomized clinical trials we aimed to address questions whether earlier detection might have impact on survival now that plenty of new treatment strategies can be offered. Also to give answers to heterogeneous surveillance strategy in real-world practice we performed a retrospective 10yr-survival analysis of a large cohort of recurrent BC patients according to their detection method.

From 4188 operable breast cancer patients who completed standard treatment Asan Medical Center from 2006 to 2008 469 patients with recurrent BC were analyzed. Median disease free interval was 35.3 months (range 2.8-97.6) and overall survival (OS) was analyzed as time from initial diagnosis/surgery to death. Among 469 patients who developed recurrence 23.7% were local (ipsilateral breast skin chest wall) 22.6% were regional (ipsilateral axillary internal mammary lymph nodes) and 53.7% developed distant metastasis. 10yr-overall survival was analyzed according to recurrent site and it's detection method.

Detection of recurrence were categorized as 'asymptomatic surveillance (N=162, 34.5%)' and 'symptom-guided (N=307, 65.5%)'. Asymptomatic screening method included mammography breast-ultrasound serum tumor marker (CA15-3) and systemic images (eg. chest X-ray bone scan PET scans). Symptom-guided detection rate for local regional and distant metastasis was 14.9%, 5.5% and 15.1% respectively. Overall asymptomatic vs symptomatic 10yr-OS did not differ (81.3 vs 78.8 months, p=0.778). Among patients with distant metastasis 10ys-OS was not significantly different (70.3 vs 66.7 months p=0.846) and was similar according to stage/subtype. Among patients with local recurrence only 10yr-OS was 95.1 months ('symptomatic' vs 'aymptomatic 94.4 vs 94.5, p=0.809) which may be insufficient number of events to show significant difference. Among regional recurrent BCs, longer OS was observed in asymptomatically detected patients than symptom-guided group (86.1 vs 63.4, p=0.004). In Cox regression analyses asymptomatic detection showed significant better survival (HR=3.9, 95%CI:1.6-9.5) and this observation was more evident in patients with hormone receptor(HR) negative primary BCs (69.9 vs 47.9, p=0.029). Intriguingly, only 8.6% (7/80) of regional recurrence were diagnosed by mammography.

We observed survival benefit with asymptomatic screening in detecting regional recurrence especially in HR-negative primary BC patients. And role of systemic radiology even in advanced high risk breast cancer patients were limited. Although with limitation that surveillance method varied widely we emphasize the role of aymptomatic surveillance of regional nodal evaluation including breast-ultrasound. These findings are to be validated from a prospective clinical study along with using cutting edge modalities other than radiology which enable detection of micro-metastasis.

Citation Format: Lee Y, Lee HS, Ahn SH, Son BH, Kim J, Lee SB. Is asymptomatic surveillance after standard treatment beneficial? : A 10yr-survival analysis of recurrent breast cancer patients by detection method of recurrence [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 P1-02-04.

Abstract P2-08-22: Clinical implication of HER2/neu status in hormone receptor positive pure mucinous breast cancer

Background: Mucinous carcinoma of the breast is a rare type of breast cancer with favorable outcome compared with other types of breast cancer. The current guideline does not recommend chemotherapy/anti-HER2 therapy for mucinous breast cancer with hormone receptor-positive subtype regardless of HER2/neu status. In this study, we evaluated the survival of pure mucinous breast cancer according to tumor stage and subtype.

Methods: Between 1989 and 2014, in Asan Medical Center, Korea, total 473 pure mucinous carcinomas (stage I-III) undergone curative surgery were reviewed retrospectively. 5yr disease-free and overall survival were analyzed according to size, lymph node metastasis, hormone receptor/HER2 status and given therapy.

Result: Total of 473 patients with pure mucinous breast cancer were analyzed and median follow-up duration was 78.00 months. 439 patients were hormone receptor-positive, 374 were node negative, 55 were HER2/neu positive. Among 374 patients with hormone receptor-positive and node-negative, tumor size was &lt;1cm in 46 patients, 1-2.9cm in 259 patients, ≥3cm in 69 patients. In HR-positive/Node-positive BCs, 90.8%(59/65)were given chemotherapy and 35.3%(6/17) were also given trastuzumab. Sixteen patients given trastuzumab were only included in the analysis to assess the benefit of trastuzumab among HER2 positive BCs.

Overall, 5-year disease-free survival (DFS) rate was 94.1% and the 5-year overall survival (OS) rate was 95.9%. Using Cox regression analysis, lymph node metastasis was the only significant prognostic factor for both DFS (HR4.0, 95%CI:1.8-9.0, p=0.001) and OS (HR3.5, 95%CI:1.3-8.9, p=0.008). Among HR-positive/node-negative with tumor size ≥3cm, HER2/neu positivity was only significantly associated with 5yr-DFS (71.4% in HER2/neu+ vs. 96.4% in HER2/neu-, HR9.5, 95%CI:1.3-67.5, p=0.024). This observation was consistently combining both 'HR-positive/node-negative/&gt;3cm' and 'HR-positive/node positive' BCs (N=127) that HER2 positive tumors showed worse survival (HR 3.7, 95%CI:1.2-10.8, p=0.015). Intriguingly, within this subgroup of HR-positive/node-negative/&gt;3cm' and 'HR-positive/node positive' BCs, among HER2 positive tumors, while 5yr-DFS was 63.7% in patients who didn't receive trastuzumab, 100% were disease free in patients who were given trastuzumab.

Conclusions: Overall, nodal status was the most significant prognostic factor for pure mucinous breast cancer. In hormone receptor-positive, lymph node negative mucinous breast cancer with tumor of ≥3cm, HER2 positive BCs showed worse survival, suggesting a potential role of anti-HER2 strategy in this subgroup.

Citation Format: Gwark S-C, Lee JW, Lee SB, Sohn G, Kim J, Chung IY, Ko BS, Kim HJ, Son BH, Ahn SH. Clinical implication of HER2/neu status in hormone receptor positive pure mucinous 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 P2-08-22.

Abstract P2-07-10: Not presented

This abstract was not presented at the conference.

Citation Format: Lee H-B, Kim KE, Ju YW, Jung J-G, Ryu H-S, Lee SB, Lee JW, Lee HJ, Kim M-S, Kwon S, Kim J, Kim C, Moon H-G, Noh D-Y, Ahn S-H, Park I-A, Kim S, Yoon S, Kim A, Han W. Not presented [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 P2-07-10.

Abstract P4-01-11: Genomic alterations of cell-free DNA in early breast cancer patients with recurrence

Cell-free DNA (cfDNA), as a non-invasive strategy, provides substantial benefit to overcome tumor heterogeneity. Surveillance of recurrence after standard treatment in early breast cancer (BC) using cfDNA, enables to detect minimal residual disease (MRD), also to identify genomic alterations driving recurrences. We aimed to assess the role of cfDNA in detecting MRD by investigating genomic alterations of 1)primary, recurred tumor and 2)cfDNA at time of recurrence using deep targeted sequencing. Fifty-four early BC patients were enrolled prospectively between 2014 and 2017 at time of recurrence. Median disease free interval was 28.5 months (rage 6.2-49.8). 62.7% (32/51) were hormone receptor (HR) positive (28 HRpos/HER2neg, 4 HRpos/HER2pos), 11.8% (6/51) were HRneg/HER2pos and 25.5% (13/51) were triple negative BCs. 59.3% (32/54) patients developed loco-regional recurrence (15 local recurrence only, 13 regional only, 4 with both) and distant metastasis was observed among 40.7% (22/54) patients. Cell-free DNA was extracted from 5cc blood at time of recurrence. Deep targeted sequencing was performed using customized NGS panel –encompassing 426 cancer-related target coding region, 242 fusion and amplification-related region- of cfDNA and FFPE(formalin fixed paraffin embedded) tumor samples archived from surgical resection or biopsy. Deep targeted sequencing data was successfully performed in 72.1% (31/43) plasma samples and sequencing yield was significantly lower when stored for more than 2yrs (46.2% vs 83.3%).

Mutations of cfDNA and tumor (primary, recurred) were analyzed. Mean sequencing depth of cfDNA and FFPE were x425.7 and x777.6 respectively. Median number of pathogenic mutations found in primary tumor, cfDNA and recurred tumor were 27(range 12-99), 25(range 8-85) and 9(range 0-23). Among mutations found in primary tumor, 27.4% were shared mutations (range 8.1%-72.7%) with recurred tumor and 26.1% were shared mutations (range 4.7%-69.2%) observed in cfDNA sample. Among mutations found in recurred tumor, 40.9% were observed in cfDNA (range 17.7-87.5%). In primary tumor, median number of mutations with allelic fraction (MAF)&gt;10% were 12 (range 4-21) and at least one mutation was found in cfDNA at time of recurrence. Among mutations with MAF&gt;10%, 59.4% and 69.1% were found in cfDNA and recurred tumor. Known oncogenic mutations of PIK3CA, TP53, GATA3, AKT1, ESR1, RELN, ERBB2, ERBB3, BRCA1 mutation were found. PIK3CA gene (p.H1047R) was found in two cases both in primary tumor and cfDNA at recurrence (MAF 11.4% vs 5.3% and 12.3% vs 15.4%) suggesting de novo driver mutation. One patient developed regional recurrence during adjuvant aromatase inhibitor with ESR1 V392I mutation in both cfDNA and recurred tumor (MAF 48.1 and 54.5%), while another patient's recurred tumor during aromatase inhibitor harbored ESR1 D538G mutation exclusively in recurred tumor with MAF &lt;1%. Both patients had no ESR1 hotpot mutation in primary tumor.

Our data showed sequencing yield of 83.3% in plasma samples within 2yr. Pathogenic mutations in primary tumor, especially when MAF&gt;10%, half of them was observed in cfDNA at time of recurrence. ESR1 mutation should be included in cfDNA surveillance for patients undergoing endocrine therapy even absent in primary tumor.

Citation Format: Kim J, Jo WK, Kim KY, Kim BJ, Lee SB, Lee HJ, Yu JH, Kim HJ, Chung IY, Ko BS, Kim S-B, Jung KH, Ahn JH, Chang S, Lee JW, Son BH, Ahn SH. Genomic alterations of cell-free DNA in early breast cancer patients with recurrence [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 P4-01-11.

Baseline physio-chemical characteristics of Sydney estuary water under quiescent conditions

The current study establishes baseline water quality properties for Sydney estuary, Australia for long periods of quiescence, which characterize the region. The study was undertaken in response to numerous requests for such data by researchers, government agencies and contractors. During quiescent periods, the range in Secchi depth transparency, turbidity, salinity and total suspended solid (TSS) values was 0.3-5.3 m, 18.6-0.1 NTU, 26.4-35.3 PSU and 8.3-1.0 mg/L in the upper and lower estuary, respectively. Baseline particulate metal concentrations were high, however TSS metal mass was greater during high rainfall. Tables and GIS-based maps allow baseline physio-chemical values to be extracted from the database for any location in Sydney estuary for quiescent conditions. Strong inter-parameter baseline relationships enable interpolation between water quality data. Baseline physio-chemical values were used to assess the impact of a high-precipitation event to demonstrate the utility of the new database.

Anion gap and base deficit are predictors of mortality in acute pesticide poisoning

BACKGROUND:

Acute pesticide poisoning has long been a serious problem as a method of suicide worldwide. This poisoning is a highly fatal condition that requires a rapid and precise diagnosis for adequate treatment. However, various studies on mortality predictor factors have been insufficient for whole pesticide treatments. We hypothesized that the initial plasma anion gap (AG) and base deficit (BD) are reliable prognostic factors.

METHODS:

A retrospective study analyzed 561 patients with a diagnosis of acute pesticide poisoning between January 1, 2014 and June 30, 2017. The initial AG and BD values were divided into quartiles according to the number of patients. Survival at 30 days from admission was estimated using the Kaplan-Meier survival analysis. Receiver-operator characteristic (ROC) curves were drawn, and the areas under the curve for AG and BD for mortality were calculated.

RESULTS:

Fifty-eight (10.3%) of 561 patients died within 30 days. The highest AG quartile (>22 mEq/L) was associated with an increased risk of 30-day hospital mortality. Compared to patients with an AG less than 14.7 mEq/L, these patients had a 4.18-fold higher risk of 30-day hospital mortality and the highest BD quartile (>7.9 mEq/L) was associated with an increased risk of 30-day hospital mortality. Compared to patients with a BD less than 1.4 mEq/L, these patients had 2.23-fold higher risk of 30-day hospital mortality. The areas under the ROC for AG and BD curve were 0.699 and 0.744, respectively.

CONCLUSIONS:

Initial high AG and BD values could predict mortality and require precise intensive care.

Geant4-DNA example applications for track structure simulations in liquid water: A report from the Geant4-DNA Project

This Special Report presents a description of Geant4-DNA user applications dedicated to the simulation of track structures (TS) in liquid water and associated physical quantities (e.g., range, stopping power, mean free path…). These example applications are included in the Geant4 Monte Carlo toolkit and are available in open access. Each application is described and comparisons to recent international recommendations are shown (e.g., ICRU, MIRD), when available. The influence of physics models available in Geant4-DNA for the simulation of electron interactions in liquid water is discussed. Thanks to these applications, the authors show that the most recent sets of physics models available in Geant4-DNA (the so-called "option4" and "option 6" sets) enable more accurate simulation of stopping powers, dose point kernels, and W-values in liquid water, than the default set of models ("option 2") initially provided in Geant4-DNA. They also serve as reference applications for Geant4-DNA users interested in TS simulations.

Abstract P1-07-29: Clinicopathologic characteristics and prognostic factors of pure mucinous breast cancer

Background: Mucinous carcinoma of the breast is a uncommon particular type of breast cancer and comprises approximately 4% of all invasive breast cancers. It is charactarized by abundant extracellular mucin production and present a more favorable prognosis than IDC-NOS. Pathologically, mucinous carcinoma is divided into two subtypes : pure and mixed. In this study, we reviewed the clinicopathologic characteristics and prognostic factors of pure mucinous carcinoma.

Methods: We reviewed the 23 years cumulative data of pure mucinous breast cancer patients from database of the Breast Cancer Center at ASAN medical center, Korea, between 1989-2011, retrospectively. Total 386 pure mucinous carcinoma cases were reviewed to analyze clinicopathologic characteristics and prognosis.

Result: Total of 386 patients with pure mucinous breast cancer were identified. Mean age was 46.7. 149 patients underwent modified radical mastectomy and 236 underwent breast-conserving therapy. The T-stage was T1 in 187 patients, T2 in 178 patients, T3 in 17 patient and T4 in 4 patients. Node negative was 325 and node positive was 61. Estrogen receptor was positive in 342 and negative in 29. Progesterone receptor was positive in 276 and negative in 95. HER-2 was positive in 47 and negative in 273. 152 patients received adjuvant chemotherapy and 240 patients received adjuvant radiotherapy. 351 patients received hormone therapy and among these patients, 231 patients were treated with Tamoxifen alone, 81 were Tamoxifen with ovarian function suppression, 37 were AI only and one patient was ovarian function suppression only. The 5 year disease free survival rate was 93.3%, 5 year cancer specific survival rate was 98.2% and 5 year overall survival rate was 96.6%. Univariate analysis showed that ER status, nodal status and Her2 status were appear to be prognostic factor of Disease free survival rate. Using Cox regression, result of multivariate analysis revealed that only nodal status is the most significant prognostic factor for survival rate.

Conclusions: Pure mucinous carcinoma of the breast is a rare subtype with a favorable prognosis. Nodal status rather than ER status, Her2 status are considered to be the most significant prognostic factor of pure mucinos breast cancer.

Citation Format: Gwark SC, Lee JW, Lee SB, Sohn G, Kim J, Chung IY, Kim HJ, Ko BS, Son BH, Ahn SH. Clinicopathologic characteristics and prognostic factors of pure mucinous breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-29.

Evaluation of bowel distension and bowel wall visualization according to patient positions during administration of oral contrast media for CT enterography

OBJECTIVE

To compare small bowel distension and bowel wall visualization among three different patients' positions (supine, sitting and right decubitus) during administration of oral contrast media in preparation for CT enterography (CTE).

METHODS

A total of 150 consecutive patients (104 males and 46 females; mean age 34.6 years, range 15-78 years) who were scheduled to undergo CTE were recruited. Patients were randomly allocated into the three position groups during oral contrast media administration, and there were 50 patients in each group. Two blinded radiologists independently scored the luminal distension and visualization of the bowel wall using a continuous 5-point scale (1: worst and 5: best) at the jejunum and ileum. The Mann-Whitney U test was used to evaluate differences between any two groups among the three positions for bowel distension and wall visualization.

RESULTS

For ileal distension, the supine and sitting positions performed better than the right decubitus position [for reader 1, mean: 3.4/3.2/2.9 (hereafter, supine/sitting/right decubitus in order), p = 0.002/0.033; for reader 2, 3.3/3.0/2.6, p < 0.001/0.027]. However, there was no significant difference among the three groups for jejunal distension (for reader 1, 2.4/2.3/2.2; for reader 2, 2.4/2.4/2.2, p > 0.05, respectively). For bowel wall visualization, the supine and sitting positions were superior to the right decubitus position for the ileum when scored by one reader (4.0/3.8/3.4, p = 0.001/0.015).

CONCLUSION

Supine and sitting positions during the administration of oral contrast media provided better ileal distension than the right decubitus position in obtaining CTE. Advances in knowledge: The performance of CTE largely depends on adequate luminal distension and wall visualization. As the terminal ileum is the predominant site of small bowel pathology for inflammatory bowel disease, the supine or sitting position would be preferable for patients who are suspected of having small bowel pathology.

Base deficit is a predictor of mortality in organophosphate insecticide poisoning

OBJECTIVE

Organophosphate insecticide (OPI) self-poisoning is a major medical problem in many countries. Several studies have demonstrated that the base deficit (BD) is a prognostic tool that is correlated with the severity of injury and predicted mortality, particularly in trauma patients. Here, we aimed to investigate the prognostic significance of BD in OPI poisoning.

METHODS

This retrospective observational study was conducted between January 1, 2006, and January 31, 2015, at a single emergency department (ED). The BD values were divided into quartiles according to the number of patients: 3 mEq/L or less, 3-5.9 mEq/L, 6-9.9 mEq/L, and 10 mEq/L or greater. Survival at 30 days from ED admission was estimated using the Kaplan-Meier survival analysis.

RESULTS

Among 154 patients, 31 died, yielding a mortality of 20.1%. The highest BD quartile (≥ 10 mEq/L) and the 6-9.9 mEq/L group were associated with an increased risk of 30-day mortality. Patients with a BD of 10 mEq/L or greater had a 5.85-fold higher risk of 30-day mortality and patients with a BD of 6-9.9 mEq/L had a 5.40-fold higher risk of 30-day mortality compared to patients with a BD of 3 mEq/L or less. The area under the curves of the BD and the Acute Physiology and Chronic Health Evaluation II score for mortality were 0.748 (95% confidence interval (CI), 0.660-0.835) and 0.852 (95% CI, 0.789-0.915), respectively.

CONCLUSIONS

This study showed that the BD is a predictor of 30-day mortality in patients with OPI poisoning.

Abstract P6-09-38: Interaction between body mass index and hormone receptor status as a prognostic factor in node-positive breast cancer

Purpose: The aim of this study was to investigate the interaction between BMI at breast cancer diagnosis and the various factors including hormone-receptor, menopausal and nodal status, and to find a specific subgroup where BMI has an effect on breast cancer prognosis.

Methods: We retrospectively analyzed the data of 8,763 non-metastatic invasive breast cancer patients from the Asan Medical Center's research database. Overall survival (OS) and breast cancer-specific survival (BCSS) among BMI groups were compared using the Kaplan-Meier method and Cox proportional hazard model with interaction term.

Results: Only in node-positive breast cancer, there was a significant interaction between obesity (BMI ≥ 30.0 kg/m2) at diagnosis and positive hormone receptor which showed worse overall survival (OS) and breast cancer specific survival (BCSS) than normal weight patients (adjusted hazard ratio [HR] = 1.65, 95% confidence interval [CI] = 1.01 to 2.69 and HR = 1.90, 95% CI = 1.15 to 3.15, respectively). Underweight (BMI&lt;18.50 kg/m2) which interacted with negative hormone receptor status in node-positive breast cancer was associated with decreased OS (HR = 2.01, 95% CI = 1.02 to 3.98) and BCSS (HR = 2.15, 95% CI = 1.08 to 4.26). There was no significant interaction between BMI and hormone receptor status in node-negative setting and BMI did not interact with menopausal status in any population.

Conclusions: BMI interacts with hormone receptor status in node positive setting, thereby playing a role in the breast cancer prognosis.

Citation Format: Chung IY, Lee JW, Lee JS, Park YR, Lee Y, Lee SB, Kim HJ, Ko BS, Son BH, Ahn SH. Interaction between body mass index and hormone receptor status as a prognostic factor in node-positive breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-38.

Effects of dietary mixture of garlic (Allium sativum), coriander (Coriandrum sativum) and probiotics on immune responses and caecal counts in young laying hens

This study was conducted to evaluate the effects of a combined mixture of phytogenic extracts (garlic and coriander) and probiotics on growth performance and immune responses in laying hens based on the results of in vitro studies to screen for immunomodulatory potency of each ingredient. Several parameters of immunomodulatory potency were estimated using lamina propria leucocytes (LPLs) isolated from rat intestinal mucosa tissue. Results show that the combined mixture enhanced LPLs proliferation, increased LPL-mediated cytotoxicity against YAC-1 tumour cells, and decreased lipopolysaccharide (LPS)-induced cytokine production including tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in LPLs. For in vivo study, laying hens (n = 50/each diet group) were fed with control diet, a diet containing antibiotics (0.01% per kg feed) or the combined mixture (0.02% per kg feed) for 21 days. The dietary combined mixture improved egg production (p < 0.05) but not growth performance and carcass traits. Interestingly, the patterns of suppressing plasma IFN-γ productions during inflammation by LPS injection and decreasing caecal E. coli counts in the combined mixture group were comparable to those in the antibiotics group. Taken together, our results suggested that the 0.02% of combined mixture of phytogenic extracts and probiotics as ingredients has potential immunomodulatory effects in laying hens.

Blue Emitters Based on Aryl End-Capped Pyrene Groups for OLEDs

We have synthesized four pyrene-derived blue emitting materials using Suzuki cross coupling reactions. All OLED devices using these materials as emitting materials showed efficient blue electroluminescence (EL). Particularly, a device using 1,1'-(9,9-dimethyl-9H-fluorene-2,7-diyl)bis-pyrene (1) showed best EL properties with the luminous efficiency of 4.32 cd/A, the power efficiency of 3.98 lm/W and the external quantum efficiency of 2.48% at 500 cd/m2.

Abstract P1-11-03: Patient reporting pain intensity immediately after surgery can be associated with underlying depression in women with breast cancer

Objective

The aims of this study were to determine the prevalence of severe, definite depression symptoms, as measured using the Center for Epidemiological Studies Depression Scale (CES-D), and the association between high CES-D scores (i.e., ≥25) and sociodemographic and perioperative factors during perioperative period.

Methods

Among 1690 consecutive breast cancer patients who were admitted for definitive breast surgery during the study period, 1499 patients were included in this study. Patients with a past medical history of psychiatric medication or support, a plan for elective surgery due to locoregional recurrence or any metastatic disease were excluded. The CES-D score was checked 1 day before definitive surgeries. The sociodemographic data and perioperative data were analyzed.

Results

The mean CES-D score was 18.5, with 24.1% (362/1499) and 56.7% (850/1499) having high CES-D scores of ≥25 and ≥16, respectively. Multivariate analysis revealed that the number of family members with any malignancy (≥2 vs 0), sedative medication (yes vs no) and postoperative numeric rating scale (NRS) scores (persistent, severe pain vs stably mild pain) were significant associated factors for severe, definite depression symptoms [CES-D score of ≥25: adjusted odds ratio (OR)=1.56, 95% confidence interval (CI)=1.10–2.21, P=0.013; adjusted OR=1.65, 95% CI=1.00–2.71, P=0.048; and adjusted OR=2.14, 95% CI=1.15–3.95, P=0.016, respectively].

Conclusion

Depression may increase the intensity of postoperative acute pain. Self-reporting of persistent postoperative pain intensity is potentially useful in detecting hidden depression symptoms in breast cancer patients during the perioperative period.

Citation Format: Kim YS, Lee JW, Kim J, Lee SB, Yu J, Ko BS, Kim HJ, Son BH, Ahn SH. Patient reporting pain intensity immediately after surgery can be associated with underlying depression in women with breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-11-03.

Novel strategy for a bispecific antibody: induction of dual target internalization and degradation

Activation of the extensive cross-talk among the receptor tyrosine kinases (RTKs), particularly ErbB family-Met cross-talk, has emerged as a likely source of drug resistance. Notwithstanding brilliant successes were attained while using small-molecule inhibitors or antibody therapeutics against specific RTKs in multiple cancers over recent decades, a high recurrence rate remains unsolved in patients treated with these targeted inhibitors. It is well aligned with multifaceted properties of cancer and cross-talk and convergence of signaling pathways of RTKs. Thereby many therapeutic interventions have been actively developed to overcome inherent or acquired resistance. To date, no bispecific antibody (BsAb) showed complete depletion of dual RTKs from the plasma membrane and efficient dual degradation. In this manuscript, we report the first findings of a target-specific dual internalization and degradation of membrane RTKs induced by designed BsAbs based on the internalizing monoclonal antibodies and the therapeutic values of these BsAbs. Leveraging the anti-Met mAb able to internalize and degrade by a unique mechanism, we generated the BsAbs for Met/epidermal growth factor receptor (EGFR) and Met/HER2 to induce an efficient EGFR or HER2 internalization and degradation in the presence of Met that is frequently overexpressed in the invasive tumors and involved in the resistance against EGFR- or HER2-targeted therapies. We found that Met/EGFR BsAb ME22S induces dissociation of the Met-EGFR complex from Hsp90, followed by significant degradation of Met and EGFR. By employing patient-derived tumor models we demonstrate therapeutic potential of the BsAb-mediated dual degradation in various cancers.

Nanoparticle formation in a chemical storage room as a new incidental nanoaerosol source at a nanomaterial workplace

Chemical storage rooms located near engineered nanomaterials (ENMs) workplaces can be a significant source of unintentional nanoaerosol generation. A new incidental nanoparticle source was identified and characterized in a chemical storage room located at an ENMs workplace. Stationary and mobile measurements using on-line instruments and chemical analysis of volatile organic compounds (VOCs) were carried out to identify the source. The number of nanoaerosols emitted from the chemical storage room was found to be several orders of magnitude higher than that existing in the ENMs workplace. VOC analysis showed that the accumulated precursors and oxygenated VOCs in the chemical storage room could be attributed to incidental particle formation via gas-to-particle conversion. We stress the importance of identification of the incidental nanoaerosols to allow characterization of the nanoaerosols at ENMs workplaces, and to estimate additional nanoaerosols exposure, which was previously unknown. Hazardous chemical substances in the workplace have been regulated in many countries; however, most of the regulations are focused on gas-phase or liquid-phase substances. The present study emphasizes the importance of secondary pollutants in particulate form that can be generated from the gas or liquid phase of hazardous chemical substances.

Physico-chemical confinement of helical nanofilaments

Helical nanofilaments (HNFs) have attracted much interest because of their unique optical properties, but there have been many hurdles to overcome in using them for the practical applications due to their structural complexity. Here we demonstrate that the molecular configuration and layer conformation of a modulated HNF (HNFs(mod)) can be studied using a physicochemical confinement system. The layer directions affected by the chemical affinity between the mesogen and surface were drastically controlled in surface-modified nanochannels. Furthermore, an in situ experiment using grazing-incidence X-ray diffraction (GIXD) was carried out to investigate in detail the structural evolution through thermal transitions. The results demonstrate that the HNF(mod) structure can be perfectly controlled for functional HNF device applications, and a combined system with chemical and physical confinement effects will be helpful to better understand the fundamentals of soft matter.

External validation of the prognostic index in acute paraquat poisoning

OBJECTIVE

Some studies have evaluated the prognostic indicators associated with acute paraquat (PQ) poisoning. In this study, we externally validated the Yamaguchi index, which showed a good prognostic relevance in predicting the outcome of PQ poisoning.

METHODS

A retrospective analysis of 297 patients was performed. The Yamaguchi index was calculated using the following equation: Eq1 = (K(+) × HCO3(-))/(Creatinine × 0.088)(mEq/L) against time from PQ ingestion (T). The patients were divided into three groups: group A: Eq1 > 1500 - 399 × log T, group B: 930 - 399 × log T < Eq1 ≤ 1500 - 399 × log T, and group C: Eq1 ≤ 930 - 399 × log T).

RESULTS

The overall mortality rate was 65.3% (194 of 297). The mortality rates of the three groups stratified by the Yamaguchi index were 7.1% (2 of 28), 22.4% (15 of 67), and 87.6% (177 of 202). The area under the receiver-operating characteristic curve for predicting mortality from the external validation of the Yamaguchi index was 0.842 (95% confidence interval: 0.795-0.882).

CONCLUSION

The Yamaguchi index is a reliable prognostic factor and could be helpful in predicting mortality due to PQ poisoning.