Development of machine learning models for the surveillance of colon surgical site infections

BACKGROUND

Conventional surgical site infection (SSI) surveillance is labour-intensive. We aimed to develop machine learning (ML) models for the surveillance of SSIs for colon surgery and to assess whether the ML could improve surveillance process efficiency.

METHODS

This study included cases who underwent colon surgery at a tertiary center between 2013 and 2014. Logistic regression and four ML algorithms including random forest (RF), gradient boosting (GB), and neural networks (NNs) with or without recursive feature elimination (RFE) were first trained on the entire cohort, and then re-trained on cases selected based on a previous rule-based algorithm. We assessed model performance based on the area under the curve (AUC), sensitivity, and positive predictive value (PPV). The estimated proportion of reduction in workload for chart review based on the ML models was evaluated and compared with the conventional method.

RESULTS

At a sensitivity of 95%, the NN with RFE using 29 variables had the best performance with an AUC of 0.963 and PPV of 21.1%. When combining both the rule-based algorithm and ML algorithms, the NN with RFE using 19 variables had a higher PPV (28.9%) than with the ML algorithm alone, which could decrease the number of cases requiring chart review by 83.9% compared with the conventional method.

CONCLUSION

We demonstrated that ML can improve the efficiency of SSI surveillance for colon surgery by decreasing the burden of chart review while providing high sensitivity. In particular, the hybrid approach of ML with a rule-based algorithm showed the best performance in terms of PPV.

Angioinvasive Mucormycosis Mimicking Mass and Pulmonary Thromboembolism in a Patient with Myelodysplastic Syndrome: A Case Report

Mucormycosis encompasses a range of fungal infections that can impact various organs. Although pulmonary mucormycosis is relatively rare, it poses a significant threat, particularly to individuals with compromised immune systems. Pulmonary mucormycosis presents with various radiological manifestations. Notably, the involvement of the angioinvasive pulmonary artery in pulmonary mucormycosis cases has seldom been documented. In this report, we showcase the radiological characteristics of angioinvasive mucormycosis, which can mimic pulmonary thromboembolism or a pulmonary artery tumor, in a patient diagnosed with myelodysplastic syndrome.

Different tumor growth pattern of clinically nonfunctioning pituitary neuroendocrine tumor according to sex and age: a longitudinal study

PURPOSE

Asymptomatic patients with clinically non-functional pituitary neuroendocrine tumors (CNF-PitNETs) are usually followed up. However, the natural course of CNF-PitNETs according to sex and age remains unclear. Therefore, this study assessed growth patterns of CNF-PitNETs according to sex and age.

METHODS

In this longitudinal study, we enrolled 431 consecutive patients with CNF-PitNETs who were treated at Seoul National University Hospital from 1997 to 2021. The patients underwent hormone function testing and visual field testing, and were subsequently followed up with imaging over a median duration of 66 months.

RESULTS

The median age of the patients was 53.0 years, and 37.1% (n = 160) were men. Men were older and harbored more macroadenomas than women. The annual tumor volume change was higher in men than in women (0.21 vs. 0.04 cm3/year, P < 0.001). The estimated cutoff value of age for significant tumor growth was 51 years. In men, the annual tumor volume change was similar across all age groups. In women, those aged ≤ 50 years showed significantly lower annual tumor volume change than those aged > 50 years (0.01, 0.11, and 0.17 cm3/year, P = 0.001). When comparing sexes within the same age group, the annual tumor volume changes was significantly lower for women than for men, only in patients aged ≤ 50 years (0.01 vs. 0.15 cm3/year, P < 0.001).

CONCLUSIONS

Among patients with CNF-PitNET, tumor growth was slower in women aged ≤ 50 years than in men and women aged > 50. These findings may guide the customization of surveillance strategies for CNF-PitNETs according to sex and age.

Comparison of Partial Versus Superficial or Total Parotidectomy for Superficial T1-2 Primary Parotid Cancers

OBJECTIVES

This study aimed to compare the oncological outcomes of partial versus superficial or total parotidectomy for superficial T1 or T2 primary parotid cancers and investigate their prognostic factors and recurrence patterns.

METHODS

The medical records of 77 patients with T1-2 primary parotid malignancies between May 2003 and March 2022 were retrospectively reviewed. Univariate and multivariate analyses were performed to evaluate the prognostic factors associated with overall survival, disease-free survival, and local and distant recurrence.

RESULTS

The average follow-up duration was 70.2 months (range, 12-202 months). The 5-year overall and disease-free survival rates were 88.7% and 77.1%, respectively. Twenty-two patients underwent partial parotidectomy, and 55 underwent superficial or total parotidectomy. There were no significant differences in the disease recurrence (P=0.320) and mortality rates (P=0.884) of the partial and superficial or total parotidectomy groups. The mean duration of surgery was shorter and the overall complication rates were significantly lower in the partial group than in the superficial or total parotidectomy group (P=0.049). Sixteen cases of recurrence occurred during the study period (20.8%). Univariate analyses showed that high-grade tumors (P=0.006), lymphovascular invasion (P=0.046), and regional lymph node metastasis (P=0.010) were significant risk factors for disease recurrence. Multivariate analysis identified regional lymph node metastasis as an independent prognostic factor for disease recurrence (P=0.027), and lymphovascular invasion as an independent prognostic factor for overall survival (P=0.033).

CONCLUSION

The conservative surgical approach of partial parotidectomy can yield oncological outcomes comparable to those of superficial or total parotidectomy with careful patient selection in T1-2 parotid cancers.

Current Trends in Artificial Intelligence-Assisted Spine Surgery: A Systematic Review

This systematic review summarizes existing evidence and outlines the benefits of artificial intelligence-assisted spine surgery. The popularity of artificial intelligence has grown significantly, demonstrating its benefits in computer-assisted surgery and advancements in spinal treatment. This study adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), a set of reporting guidelines specifically designed for systematic reviews and meta-analyses. The search strategy used Medical Subject Headings (MeSH) terms, including "MeSH (Artificial intelligence)," "Spine" AND "Spinal" filters, in the last 10 years, and English- from January 1, 2013, to October 31, 2023. In total, 442 articles fulfilled the first screening criteria. A detailed analysis of those articles identified 220 that matched the criteria, of which 11 were considered appropriate for this analysis after applying the complete inclusion and exclusion criteria. In total, 11 studies met the eligibility criteria. Analysis of these studies revealed the types of artificial intelligence-assisted spine surgery. No evidence suggests the superiority of assisted spine surgery with or without artificial intelligence in terms of outcomes. In terms of feasibility, accuracy, safety, and facilitating lower patient radiation exposure compared with standard fluoroscopic guidance, artificial intelligence-assisted spine surgery produced satisfactory and superior outcomes. The incorporation of artificial intelligence with augmented and virtual reality appears promising, with the potential to enhance surgeon proficiency and overall surgical safety.

Development and Validation of a Robust and Interpretable Early Triaging Support System for Patients Hospitalized With COVID-19: Predictive Algorithm Modeling and Interpretation Study

BACKGROUND

Robust and accurate prediction of severity for patients with COVID-19 is crucial for patient triaging decisions. Many proposed models were prone to either high bias risk or low-to-moderate discrimination. Some also suffered from a lack of clinical interpretability and were developed based on early pandemic period data. Hence, there has been a compelling need for advancements in prediction models for better clinical applicability.

OBJECTIVE

The primary objective of this study was to develop and validate a machine learning-based Robust and Interpretable Early Triaging Support (RIETS) system that predicts severity progression (involving any of the following events: intensive care unit admission, in-hospital death, mechanical ventilation required, or extracorporeal membrane oxygenation required) within 15 days upon hospitalization based on routinely available clinical and laboratory biomarkers.

METHODS

We included data from 5945 hospitalized patients with COVID-19 from 19 hospitals in South Korea collected between January 2020 and August 2022. For model development and external validation, the whole data set was partitioned into 2 independent cohorts by stratified random cluster sampling according to hospital type (general and tertiary care) and geographical location (metropolitan and nonmetropolitan). Machine learning models were trained and internally validated through a cross-validation technique on the development cohort. They were externally validated using a bootstrapped sampling technique on the external validation cohort. The best-performing model was selected primarily based on the area under the receiver operating characteristic curve (AUROC), and its robustness was evaluated using bias risk assessment. For model interpretability, we used Shapley and patient clustering methods.

RESULTS

Our final model, RIETS, was developed based on a deep neural network of 11 clinical and laboratory biomarkers that are readily available within the first day of hospitalization. The features predictive of severity included lactate dehydrogenase, age, absolute lymphocyte count, dyspnea, respiratory rate, diabetes mellitus, c-reactive protein, absolute neutrophil count, platelet count, white blood cell count, and saturation of peripheral oxygen. RIETS demonstrated excellent discrimination (AUROC=0.937; 95% CI 0.935-0.938) with high calibration (integrated calibration index=0.041), satisfied all the criteria of low bias risk in a risk assessment tool, and provided detailed interpretations of model parameters and patient clusters. In addition, RIETS showed potential for transportability across variant periods with its sustainable prediction on Omicron cases (AUROC=0.903, 95% CI 0.897-0.910).

CONCLUSIONS

RIETS was developed and validated to assist early triaging by promptly predicting the severity of hospitalized patients with COVID-19. Its high performance with low bias risk ensures considerably reliable prediction. The use of a nationwide multicenter cohort in the model development and validation implicates generalizability. The use of routinely collected features may enable wide adaptability. Interpretations of model parameters and patients can promote clinical applicability. Together, we anticipate that RIETS will facilitate the patient triaging workflow and efficient resource allocation when incorporated into a routine clinical practice.

Connecting the S2 alar-iliac screw head to the satellite rod for surgical correction of degenerative sagittal imbalance

PURPOSE

The S2AI screw technique has several advantages over the conventional iliac screw fixation technique. However, connecting the S2AI screw head to the main rod is difficult due to its medial entry point. We introduce a new technique for connecting the S2AI screw head to a satellite rod and compare it with the conventional method of connecting the S2AI screw to the main rod.

METHODS

Seventy-four patients who underwent S2AI fixation for degenerative sagittal imbalance and were followed up for ≥ 2 years were included. All the patients underwent long fusion from T9 or T10 to the pelvis. The S2AI screw head was connected to the satellite rod (SS group) in 43 patients and the main rod (SM group) in 31 patients. In the SS group, the satellite rod was placed medial to the main rod and connected by the S2AI screw and domino connectors. In the SM group, the main rod was connected directly to the S2AI screw head and supported by accessory rods. Radiographic and clinical outcomes were evaluated in both groups.

RESULTS

There were no significant differences in postoperative complications, including proximal junctional failure, proximal junctional kyphosis, rod breakage, screw loosening, wound problems, and infection between the two groups. Furthermore, the correction power of sagittal deformity and clinical results in the SS group were comparable to those in the SM group.

CONCLUSION

Connecting the S2AI screw to the satellite rod is a convenient method comparable to the conventional S2AI connection method in terms of radiological and clinical outcomes.

Enhanced Cholesterol-Lowering and Antioxidant Activities of Soymilk by Fermentation with Lactiplantibacillus plantarum KML06

This study aimed to evaluate the cholesterol-lowering and antioxidant activities of soymilk fermented with probiotic Lactobacillaceae strains and to investigate the production of related bioactive compounds. Lactiplantibacillus plantarum KML06 (KML06) was selected for the fermentation of soymilk because it has the highest antioxidant, cholesterol-lowering, and β-glucosidase activities among the 10 Lactobacillaceae strains isolated from kimchi. The genomic information of strain KML06 was analyzed. Moreover, soymilk fermented with KML06 was evaluated for growth kinetics, metabolism, and functional characteristics during the fermentation period. The number of viable cells, which was similar to the results of radical scavenging activities and cholesterol assimilation, as well as the amount of soy isoflavone aglycones, daidzein, and genistein, was the highest at 12 h of fermentation. These results indicate that soymilk fermented with KML06 can prevent oxidative stress and cholesterol-related problems through the production of soy isoflavone aglycones.

An extremely energetic cosmic ray observed by a surface detector array

Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come from extragalactic sources. Their arrival is infrequent, so detection requires instruments with large collecting areas. In this work, we report the detection of an extremely energetic particle recorded by the surface detector array of the Telescope Array experiment. We calculate the particle's energy as [Formula: see text] (~40 joules). Its arrival direction points back to a void in the large-scale structure of the Universe. Possible explanations include a large deflection by the foreground magnetic field, an unidentified source in the local extragalactic neighborhood, or an incomplete knowledge of particle physics.

[Primary Malignant Peripheral Nerve Sheath Tumor of the Pulmonary Vein: A Case Report]

Primary masses rarely originate from the heart and great vessels, and a malignant peripheral nerve sheath tumor (MPNST) is extremely rare. A 76-year-old male with pleural effusion underwent contrast-enhanced computed tomography, which revealed a hypoattenuating mass involving the right pulmonary vein and left atrium. Ultrasonography showed that the mass originated from the right pulmonary vein. Surgical resection confirmed an MPNST that originated from the pulmonary vein. We report the first Korean case of a primary MPNST originating from the pulmonary vein. We have also described the radiologic findings suggestive of a pulmonary vein mass.

Hippocampal Sparing Whole Brain Radiation Therapy: 2 Arc Coplanar and 4 Arc Noncoplanar Planning Comparison

PURPOSE/OBJECTIVE(S)

Whole brain radiation therapy (WBRT) has been shown to provide palliation but with negative neurocognitive effects associated with radiation-induced damage to the hippocampus. Sparing of the hippocampus has been shown to reduce the risk of neurocognitive deficit. Hippocampal sparing WBRT plan optimization is commonly done using 2 arc coplanar technique. The purpose of this work is to show that 4 arc noncoplanar plans will improve hippocampal sparing without compromising PTV coverage.

MATERIALS/METHODS

Retrospective WBRT with hippocampal sparing using 2 arc coplanar and 4 arc noncoplanar VMAT technique were done on 10 patients previously treated for intracranial lesions. CT and MRI fused images were used to delineate the whole brain and hippocampus. Strictly following RTOG 0933 atlas guidelines, the hippocampus was manually delineated by a single Radiation Oncologist. Plans with prescription dose of 30 Gy in 10 fractions were generated using the 2 techniques. The 4 arc noncoplanar plan included 2 partial field arcs with couch angle at 90 degrees and 2 coplanar arcs. The 2 noncoplanar partial arcs consisted of a clockwise arc and a counterclockwise arc with gantry angles between 5 and 179 degrees. Lens were kept to < 7 Gy and pituitary gland to < 30 Gy. Dosimetric parameters from both techniques were compared by paired t-test.

RESULTS

Radiation dose to the hippocampus was significantly reduced using 4 arc noncoplanar plan when compared to 2 arc coplanar plan. While hippocampus D100% were similar (7.25 Gy vs 7.32 Gy, p = 0.557), the mean dose (9.46 Gy vs 9.87 Gy, p = 0.003) and D0.03cc (12.48 Gy vs 12.94 Gy, p < 0.001) were significantly reduced with 4 arc noncoplanar plans. Whole brain PTV coverage remained at V100% = 95% for both techniques. However, the 4 arc noncoplanar plans showed significantly improved D2% (32.56 Gy vs 32.97 Gy, P = 0.003), D98% (28.11 Gy vs 27.91 Gy, P = 0.01), and homogeneity index (0.141 vs 0.159, P < 0.001).

CONCLUSION

The 4 arc noncoplanar plans improved hippocampal sparing without compromising PTV coverage or compromise to other nearby organs at risk.

Assessment of Bladder Filling Type on Radiation Dose to Organs at Risk in MR-Guided Intracavity Brachytherapy for Cervical Cancer

PURPOSE/OBJECTIVE(S)

In this study, we evaluated whether the classification of bladder shape affects the absorbed dose (Gy) of OARs and its geometrical position to normal organs in MR-guided intracavitary brachytherapy (ICBT).

MATERIALS/METHODS

In this study, 269 patients who underwent MR-guided ICBT for cervical cancer from 2016 to 2022 were included. The applicator-inserted bladder filling type (BFT) classification was divided into three types (tilted, curved, and other shapes: group E). The anatomical positional relationship between the uterus and its surroundings was measured on pre-MR images and ICBT simulation MR images. Spearman's rank correlation analysis was used for bladder volume and OAR dose according to BFT. Anatomical differences were analyzed by ANOVA by measuring the distance from the center to both bladder walls.

RESULTS

In the correlation analysis considering the shape of the bladder, the tilted, curved, and group E had Spearman's ρ of 0.211; -0.323, 0.412; -0.307 and -0.035; -0.209 for maximum absorbed dose (D2cc) of bladder and small bowel, respectively. It was statistically significant in the tilted type and curved type. The average left and right bladder lengths differences of the tilted type were the highest at 8.47 cm and 7.11 cm, respectively. It was a statistically significant between bladder shape and the difference in left and right bladder lengths differences (p< 0.01).

CONCLUSION

In this study, it was confirmed that bladder distension increased the maximum bladder dose (D2cc) and decreased the maximum bowel dose (D2cc) to the tilted type and curved type. In addition, if the left and right bladder lengths are measured in pre-MR, the degree of bladder distension can be evaluated in advance by checking the shape of the bladder in the case of the tilting type before ICBT. Based on these findings, a prospective study is needed to evaluate the effect of ICBT on cervical cancer treatment outcomes through bladder type classification.

Surgical complications and incomplete canal widening of the vertebral body sliding osteotomy to treat cervical myelopathy

OBJECTIVE

Vertebral body sliding osteotomy (VBSO) is a surgical technique that anteriorly translates the vertebral body with compressive lesions and achieves cord decompression through canal widening. However, data on the surgical complications of VBSO are lacking. Furthermore, it has not been known whether VBSO could be a viable alternative in the treatment of cervical myelopathy even when the preoperative canal-occupying ratio (COR) is large, which seems to frequently result in incomplete canal widening. This study aimed to describe the incidence of VBSO-associated surgical complications and to evaluate the incidence and risk factors of incomplete canal widening.

METHODS

A total of 109 patients who underwent VBSO to treat cervical myelopathy were retrospectively reviewed. Neck pain visual analog scale, Neck Disability Index, Japanese Orthopaedic Association (JOA) scores, and surgical complications were evaluated. For radiological evaluation, C2-7 lordosis, C2-7 sagittal vertical axis, and COR were measured. Patients with a preoperative COR < 50% (n = 60) and those with a COR ≥ 50% (n = 49) were compared and logistic regression analysis was performed to identify factors associated with incomplete canal widening.

RESULTS

The most frequent complication in the patients was mild dysphagia (7.3%). Dural tears were observed during posterior longitudinal ligament resection (n = 1) and foraminotomy (n = 1). Two patients underwent reoperation due to radiculopathy from adjacent-segment disease. Incomplete canal widening occurred in 49 patients. According to logistic regression analysis, high preoperative COR was the only factor associated with incomplete canal widening. The amount of canal widening and JOA recovery rate in the COR ≥ 50% group were significantly higher than in the COR < 50% group.

CONCLUSIONS

Mild dysphagia was the most common complication following VBSO. Although VBSO aims to decrease the complication rate of corpectomy, it was not free of dural tears. Special care would be required during the posterior longitudinal ligament resection. Incomplete canal widening occurred in 45.0% of patients, and high preoperative COR was the only risk factor for incomplete canal widening. However, high preoperative COR would not be a contraindication for VBSO, given that favorable clinical outcomes were presented in the COR ≥ 50% group.

Definitive Radiotherapy in Patients with Clinical T1N0M0 Esophageal Squamous Cell Carcinoma: A Multicenter Retrospective Study

PURPOSE/OBJECTIVE(S)

In this study, we aimed to assess the failure pattern and survival outcomes and to analyze the optimal treatment field of definitive RT for T1N0M0 esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

We performed a retrospective analysis in a multi-institutional cohort of patients with histologically confirmed T1N0M0 ESCC. We included patients who underwent RT with definitive aim from 2010 to 2019. Patterns of failure were demonstrated as in-field locoregional, out-field locoregional and distant metastasis. In the survival analysis, freedom from locoregional recurrence and their association with clinicopathologic risk factors were analyzed. We performed a propensity score matching in the cT1b patients to adjust for the heterogeneity of radiation technique, radiation dose and the use of concurrent chemotherapy.

RESULTS

A total of 168 patients were included with a median follow-up of 34.0 months, and there were 20 cT1a, 94 cT1b and 24 cT1x, (cT1, not otherwise specified) patients. The rates of all and locoregional failure were 26.9% and 23.1% for cT1a and 25.0% and 22.4% for cT1b patients. 10 (10.6%) patients experienced grade ≥ 3 adverse events. Among 116 cT1b patients, 69 patients received elective nodal irradiation (ENI) and 47 patients received involved field irradiation (IFI). After propensity score matching, the 3-year FFLRR rate was 84.5% (95% Confidence Interval, 71.0 - 92.1%). There was no significant difference between the ENI and IFI patients in FFLRR (Log-rank P = 0.831). In the multivariate analysis, the use of concurrent chemotherapy was the only factor marginally associated with FFLRR (Hazard ratio, 0.17; 95% CI, 0.02 - 1.13; P = 0.067).

CONCLUSION

cT1a patients who cannot receive endoscopic resection, showed similar rates of failure compared with cT1b patients, which questioned the accuracy of the staging and raised the need for through treatment such as chemoradiotherapy. In cT1b patients, IFI using dose of 50 to 60 Gy with concurrent chemotherapy could be a reasonable treatment option.

Impact of the New ESTRO-ACROP Target Volume Delineation Guideline on Breast-Related Complications after Implant-Based Reconstruction and Postmastectomy Radiotherapy

PURPOSE/OBJECTIVE(S)

The European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) recently updated a new target volume delineation guideline for postmastectomy radiotherapy (PMRT) after implant-based reconstruction. This study aimed whether this change has impact on breast-related complications.

MATERIALS/METHODS

We retrospectively reviewed patients who underwent PMRT after mastectomy with tissue expander or permanent implant insertion from 2016 to 2021. In total, 412 patients were included; 277 received RT by the new ESTRO-ACROP target delineation (ESTRO-T), and 135 received RT by conventional target delineation (CONV-T). The primary endpoint was comparison between the target groups of major breast-related complication, including infection, capsular contracture, deformity and necrosis requiring re-operation or re-hospitalization during follow-up after RT or delayed implant replacement. Complications were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0., and capsular contracture was graded by the Baker Classification.

RESULTS

The median follow-up was 29.5 months (range, 0.3-76.8). The 1-, 2-, and 3-year incidence rates of major breast-related complication were 5.7%, 10.0%, and 11.6% in the ESTRO-T group, and 8.2%, 13.8%, and 14.7% in the CONV-T groups; it did not show a difference between the groups (P = 0.55). In multivariate analyses, target delineation is not significantly associated with the major complications (hazard ratio [HR] = 0.93; P = 0.83, Table 1). There was no significant difference between the ESTRO-T and CONV-T groups in the incidence of any breast-related complications (3-year cumulative incidence, 37.3% vs. 29.4%, respectively; P = 0.28). Symptomatic RT-induced pneumonitis rates were 2.7% in the ESTRO-T group (7 patients) and 2.2% in the CONV-T group (3 patients). Only one local recurrence event occurred in the ESTRO-T group, which was within the ESTRO-target volume.

CONCLUSION

Target volume delineation according to the new ESTRO-ACROP guideline did not reduce the risk of major or any breast-related complications. As the dosimetric benefits of heart and lung have been reported, further analyses with long-term follow-up are necessary to evaluate whether it could be connected to better clinical outcomes.

Prognostic Value of Depth of Invasion in Squamous Cell Carcinoma of the Oral Cavity of Size 4 cm or Less

PURPOSE/OBJECTIVE(S)

We aimed to evaluate the role of the depth of invasion (DOI) as an independent prognostic factor in the absence of other adverse features in squamous cell carcinoma (SqCC) of the oral cavity with a size of 4 cm or less.

MATERIALS/METHODS

We performed a retrospective analysis in a multi-institutional cohort of patients with oral cavity SqCC, size of 4 cm or less. We included those who were treated with upfront surgery with negative resection margins from 2010 to 2021 and those with one or no nodal metastasis. Those who were treated with postoperative radiotherapy were excluded. The DOI and other adverse features, such as close resection margins, lymphovascular invasion, perineural invasion, and nodal metastasis, were evaluated in univariate and multivariate analyses for their association with locoregional recurrence (LRR).

RESULTS

A total of 155 patients were included with a median follow-up of 23.7 months. 56 patients (36.1%) had DOI greater than 5 mm. 26 patients (16.8%) experienced LRR and one experienced distant metastasis. Multivariate analysis showed that DOI was the only prognostic factor associated with a higher rate of LRF (p = 0.004). The 2-year LRF rates of those with DOI ≤ 5 mm and DOI > 5mm were 4.7% and 30.3%, respectively.

CONCLUSION

This study implies that DOI greater than 5 mm may be an independent prognostic factor of the SqCC of the OCC and may be indicated for adjuvant radiotherapy.

Treatment Outcomes of Stereotactic Body Radiation Therapy for Pulmonary Metastasis from Sarcoma: A Multicenter, Retrospective Study

PURPOSE/OBJECTIVE(S)

The aim of this study was to evaluate the treatment outcomes and potential dose-response relationship of stereotactic body radiation therapy (SBRT) for pulmonary metastasis of sarcoma.

MATERIALS/METHODS

A retrospective review of 39 patients and 71 lesions treated with SBRT from two institutions was performed. The patients had oligometastatic or oligoprogressive disease, or were receiving palliation. Doses of 20-60 Gy were delivered in 1-5 fractions. The local control per tumor (LCpT) was evaluated according to the biologically effective dose with an α/β ratio of 10 (BED10) of the prescribed dose (BED10 ≥ 100 Gy vs. BED10 < 100 Gy). Clinical outcomes per patient, including local control per patient (LCpP), pulmonary progression-free rate (PPFR), any progression-free rate (APFR), and overall survival (OS) were investigated.

RESULTS

The median follow-up period was 27.2 months. The 1-, 2-, and 3-year LCpT rates for the entire cohort were 100.0%, 88.3%, and 73.6%, respectively. There was no observed difference in LCpT between the two BED10 groups (p = 0.180). The 3-year LCpP, PPFR, APFR, and OS rates were 78.1%, 22.7%, 12.9%, and 83.7%, respectively. Five (12.8%) patients with oligometastasis had long-term disease-free intervals, with a median survival period of 40.7 months. Factors that were associated with a worse prognosis were oligoprogression (vs. oligometastasis), multiple pulmonary metastases, and simultaneous extrathoracic metastasis.

CONCLUSION

SBRT for pulmonary metastasis of sarcoma is effective. Some selected patients may achieve durable response. Considerations of SBRT indication and disease extent may be needed as they may influence the prognosis.

Improving Ultrasound Visualization of Catheters During Interstitial Brachytherapy

PURPOSE/OBJECTIVE(S)

Interstitial brachytherapy utilizes catheters to deliver high doses of radiation directly to target tissues. Proper catheter placement is vital to successful treatment and patient outcome. To ensure effective internal guidance, catheters are often positioned under real-time ultrasound (US) in the operating room, with post-operative confirmation using axial imaging. However real-time catheter localization is often difficult due to poor catheter visualization, which can result in ineffectual treatment, reduced organ-sparing, or catheter intrusion into surrounding organs. In the current space for this oncological technique, there are no devices or methods that aim to improve the visualization of catheters which leverage the convenience and accessibility of real-time ultrasound, hindering the optimization of procedural outcomes.

MATERIALS/METHODS

To address this need, our team designed a piezo material-integrated medical accessory to integrate the qualitative visualization of color Doppler US into interstitial brachytherapy procedures. The device transduces low-magnitude vibration to brachytherapy catheters to be detected in tissue under real-time B-mode US. Upon activation, the device propagates vibrations down the length of brachytherapy catheters, allowing color Doppler to detect and display repeated, internal movements to assist the operator in catheter placement. Active adjustability over the voltage output using a simple circuit with potentiometer control allows the user to directly control the magnitude and frequency of vibration, offering real-time visualization during interstitial brachytherapy. Pivotal elements of this design include a noninvasive integration into existing brachytherapy workflows, a reproducible and low-cost 3D-printed design, compatibility with real-time US catheter visualization, and highly specific control over the magnitude of Doppler visualization with catheter detachability and dial-regulated voltage/vibration adjustment.

RESULTS

The device is able to qualitatively increase the visualization of brachytherapy catheters in a simulated brachytherapy procedure using a custom US phantom at moderate to extreme operational depths, while also staying within safety thresholds set by international standards for medical/electronic/handheld accessories in regards to heat generation, housing weight, and vibrational exposure. Results obtained using an obstructive US phantom with 10-15 cm depth, which consists of fruits, airway through the phantom, and multiple catheters in a localized area, allowed us to clearly distinguish the catheter of interest from the rest of the structures, even in the presence of highly intrusive noise and shadowing CONCLUSION: Brachytherapy catheter visualization can be improved using low-magnitude vibration transmitted through the brachytherapy catheter detected under real-time B-mode US. Further research and clinical testing are ongoing.

Association of body mass index and bloodstream infections in patients on extracorporeal membrane oxygenation: a single-centre, retrospective, cohort study

BACKGROUND

Obesity is associated with poor clinical outcomes in critically ill patients. However, under some clinical conditions, obesity has protective effects. Bloodstream infections (BSI) are among the most common nosocomial infections associated with extracorporeal membrane oxygenation (ECMO). BSI during ECMO is associated with higher mortality rates and poorer clinical outcomes.

AIM

To analyse whether body mass index (BMI) is associated with BSI during ECMO or with in-hospital mortality.

METHODS

All adult patients who had received ECMO support for >48 h were included in the analysis. The analysis of total duration of ECMO support, in-hospital mortality and BSI was stratified by BMI category. The Cox proportional hazards model was used to compare the risk of BSI among BMI categories.

FINDINGS

In total, 473 patients were enrolled in the study. The average age was 56.5 years and 65.3% were men. The total duration of ECMO was approximately 11.8 days, with a mortality rate of 47.1%. The incidence rates of BSI and candidaemia were 20.5% and 5.5%, respectively. The underweight group required ECMO for respiratory support, whereas the overweight and obese groups required ECMO for cardiogenic support (P<0.0001). No significant difference in BSI rate was found (P=0.784). However, after adjusting for clinical factors, patients in Group 4 (BMI 25.0-<30.0 kg/m2) exhibited lower mortality compared with patients in Group 2 (normal BMI) (P=0.004).

CONCLUSION

BMI was not associated with risk of BSI, but patients with higher BMI showed lower in-hospital mortality associated with ECMO support.

Insidious Onset Multifocal Chest Wall and Spinal Abscess Caused by Previous Candidemia: A Case Report

Abscess formation due to Candida albicans infection is extremely rare. Radiological diagnosis of an atypical abscess at an uncommon site is challenging. In this study, we present a case of insidious onset multifocal chest wall and spinal abscess after candidemia in a young woman in the intensive care unit due to postpartum bleeding.

Erratum: Correction of Affiliations in the Article "Establishment of a Nationwide Korean Imaging Cohort of Coronavirus Disease 2019"

This corrects the article on p. e413 in vol. 35, PMID: 33258333.

Correction: Deep Learning With Chest Radiographs for Making Prognoses in Patients With COVID-19: Retrospective Cohort Study

[This corrects the article DOI: 10.2196/42717.].

Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions

The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at sqrt[s_{NN}]=5.02  TeV, corresponding to an integrated luminosity of 0.38  nb^{-1}, collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.

Network analysis of osteoporosis provides a global view of associated comorbidities and their temporal relationships

We performed comorbidity-network analysis to obtain global view of comorbidity related with osteoporosis. We selected 10000-patients with osteoporosis registered in the National-Health-Insurance Service cohort-database. We found 45-significant disease-clusters. Of these, 14-disease-clusters were related to fra, while 10 were related to musculoskeletal diseases. Our findings will serve as basic data for further studies.

PURPOSE

Osteoporosis causes devastating fractures; however, its exact etiology remains unknown. Elucidating associated comorbidities and their temporal relationships could provide better insights into its pathogenesis. Comorbidity-network analysis was performed to obtain global view of these associations.

METHODS

We randomly selected 10000-patients with osteoporosis registered in the National-Health-Insurance Service cohort-database. These patients were identified using ICD-10 codes M81-M82, which represent osteoporosis without pathological fractures. Control group was created through propensity score matching. The comorbidities in each group were grouped into similar classifications to form "disease cluster"; 126 such clusters were identified. To create a comorbidity network, we selected disease clusters with high associations (i.e., odds ratios and relative risks ranked in the upper 50^th percentile). To identify the temporal relationships between these clusters and osteoporosis, trajectories of directions were identified.

RESULTS

Finally, we found 45 significant disease clusters. Of these, 14 disease clusters were related to fractures or injuries, while 10 were related to musculoskeletal diseases. Temporal analysis revealed that 15 disease clusters preceded osteoporosis; these included the following three with the strongest associations: "other fracture", "disorders of bone density and structure (M83-M85)", and "sequelae of injuries of neck and trunk (T91)". Thirty disease clusters followed osteoporosis; these included the following three with the strongest associations: "spine fracture," "spondylopathies (M45-M49)", and "pelvic region and thigh fracture,".

CONCLUSION

We obtained a global view of the osteoporosis comorbidity network, which is otherwise difficult to achieve through study of individual diseases. Our findings will serve as the basic data for further studies.

Vertebral Body Sliding Osteotomy as a Surgical Strategy for the Treatment of Cervical Myelopathy: Complications and Pitfalls

OBJECTIVE

This retrospective cohort study has been aimed at evaluating the incidence of complications after vertebral body sliding osteotomy (VBSO) and analyzing some cases. Furthermore, the complications of VBSO were compared with those of anterior cervical corpectomy and fusion (ACCF).

METHODS

This study included 154 patients who underwent VBSO (n = 109) or ACCF (n = 45) for cervical myelopathy and were followed up for > 2 years. Surgical complications, clinical and radiological outcomes were analyzed.

RESULTS

The most common surgical complications after VBSO were dysphagia (n = 8, 7.3%) and significant subsidence (n = 6, 5.5%). There were 5 cases of C5 palsy (4.6%), followed by dysphonia (n = 4, 3.7%), implant failure (n = 3, 2.8%), pseudoarthrosis (n = 3, 2.8%), dural tears (n = 2, 1.8%), and reoperation (n = 2, 1.8%). C5 palsy and dysphagia did not require additional treatment and spontaneously resolved. The rates of reoperation (VBSO, 1.8%; ACCF, 11.1%; p = 0.02) and subsidence (VBSO, 5.5%; ACCF, 40%; p < 0.01) were significantly lower in VBSO than in ACCF. VBSO restored more C2-7 lordosis (VBSO, 13.9° ± 7.5°; ACCF, 10.1° ± 8.0°; p = 0.02) and segmental lordosis (VBSO, 15.7° ± 7.1°; ACCF, 6.6° ± 10.2°; p < 0.01) than ACCF. The clinical outcomes did not significantly differ between both groups.

CONCLUSION

VBSO has advantages over ACCF in terms of low rate of surgical complications related to reoperation and significant subsidence. However, dural tears may still occur despite the lessened need for ossified posterior longitudinal ligament lesion manipulation in VBSO; hence, caution is warranted.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, staging and treatment of patients with metastatic breast cancer

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, staging and treatment of patients with metastatic breast cancer (MBC) was published in 2021. A special, hybrid guidelines meeting was convened by ESMO and the Korean Society of Medical Oncology (KSMO) in collaboration with nine other Asian national oncology societies in May 2022 in order to adapt the ESMO 2021 guidelines to take into account the differences associated with the treatment of MBC in Asia. These guidelines represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with MBC representing the oncological societies of China (CSCO), India (ISMPO), Indonesia (ISHMO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO). The voting was based on the best available scientific evidence and was independent of drug access or practice restrictions in the different Asian countries. The latter were discussed when appropriate. The aim of these guidelines is to provide guidance for the harmonisation of the management of patients with MBC across the different regions of Asia, drawing from data provided by global and Asian trials whilst at the same time integrating the differences in genetics, demographics and scientific evidence, together with restricted access to certain therapeutic strategies.

CT-based three-dimensional invasiveness analysis of adenocarcinoma presenting as pure ground-glass nodules

Background

We invest computed tomography (CT) image differences between non-invasive adenocarcinomas (NIAs) and invasive adenocarcinomas (IAs) presenting as pure ground glass nodules (GGNs).

Methods

From 2013 to 2019, 48 pure GGNs were surgically resected in 45 patients. Of these, 40 were pathologically diagnosed as non-small cell lung cancers (NSCLCs). We assessed them using the Synapse Vincent (Fujifilm Co., Ltd., Tokyo, Japan) three-dimensional (3D) analysis system; we drew histograms of the CT densities. We calculated the maximum, minimum, means, and standard deviations of the densities. The proportions of GGNs of high CT density were compared between the two groups. The diagnostic performance was investigated via receiver operating curve (ROC) analysis.

Results

Of the 40 pure GGNs, 20 were NIAs (4 adenocarcinomas in situ and 16 minimally IAs) and 20 IAs. Significant correlations were evident between histological invasiveness and the maximum and mean CT densities and the standard deviation. Neither the nodule volume nor the minimum CT density significantly predicted invasiveness. A CT volume density proportion >-300 Hounsfield units optimally predicted the invasiveness of pure GGNs; the cutoff was 5.41% with a sensitivity of 85% and a specificity of 95%.

Conclusions

CT density reflected the invasiveness of pure GGNs. A CT volume proportion density >-300 Hounsfield units may significantly predict histological invasiveness.

Urine phthalate levels were associated with skin barrier dysfunction and atopic sensitization in children

OBJECTIVE

Phthalates can cause immunological disorders and aggravate allergic diseases. Thus, we investigated the relationship between urinary phthalate, skin barrier function, and atopic sensitization in children.

PATIENTS AND METHODS

In total, 448 school children [334 with severe allergic disease; and 123 with severe atopic dermatitis (AD)] aged 10-12 years were enrolled in this study between June and July 2017. Four high-molecular-weight phthalates (HMWP) [Σ4HMWP] and three low-molecular-weight phthalates (LMWP) [Σ3LMWP] metabolites in urine samples, specific immunoglobulin E (IgE), and total eosinophil count were measured. Four-part trans epidermal water loss (TEWL) (cheek, leg, and upper/lower arm; Σ4TEWL) was measured to evaluate the skin barrier function.

RESULTS

After adjusting for confounding variables, Σ4TEWL was significantly associated with the quartiles of urinary Σ4HMWP [adjusted β=7.897, 95% confidence interval (CI): 0.636-15.158, p=0.033] and Σ3LMWP (adjusted β=9.670, 95% CI: 2.422-16.919, p=0.009). The adjusted analyses revealed that the quartiles of urinary Σ4HMWP and Σ3LMWP were not significantly associated with total eosinophil count, atopic sensitization, and severe AD (p>0.05). According to the quartiles of urinary Σ4HMWP and Σ3LMWP, there were significant differences in the TEWL of the lower arm and leg (p<0.05) but not in cheek and upper arm.

CONCLUSIONS

Exposure to HMWPs and LMWPs was significantly associated with skin barrier dysfunction but not with atopic sensitization. These results suggest that children exposed to phthalates may be more susceptible to fragile skin barrier function.

Significance of photodocumentation-associated factors in colonoscopy on the detection rate of colorectal neoplasms

OBJECTIVE

It is unclear whether photodocumentation is associated with colorectal neoplasm (CRN) detection at colonoscopy, despite its ability to take more images with the development of affordable digital imaging systems. This study aimed to investigate whether photodocumentation-related factors could affect the detection rate of CRNs in healthy subjects.

PATIENTS AND METHODS

A total of 2,637 subjects undergoing screening colonoscopy in routine health check-ups at CHA Bundang Medical from January to September 2016 were enrolled in this study. Only the endoscopic image data for observation purposes during colonoscopy withdrawal was used in this analysis. The number of observation images, observation time and the speed of photodocumentation (SPD) defined as the number of observation images per minute were used as quantity measures of photodocumentation. The presence of documented anatomical landmarks such as appendix orifice (AO), ileocecal valve (ICV), anorectal junction was used as quality measures of photodocumentation.

RESULTS

Among subject-related factors, the independent factors for CRN detection in the multivariate analysis were age, male sex, waist circumference, and family history of colorectal cancer. In photo-documentation-related factors, SPD [Odds ratio (OR) 0.800; 95% confidence interval (CI), 0.740 to 0.864], observation time over 6 min (OR 1.671; 95% CI, 1.145 to 2.439), clear documentation of appendix orifice (AO) (OR 5.976; 95% CI, 4.548 to 7.852) and ileocecal valve (ICV) (OR 3.826; 95% CI, 2.985 to 4.904), and endoscopists (p < 0.001) were independently significant factors. However, the number of observation images was not associated with the detection of CRNs.

CONCLUSIONS

Lower SPD and clear documentation of cecal landmarks might be associated with an increased detection rate of CRNs.

Impact of tuberculosis on the incidence of osteoporosis and osteoporotic fractures: a nationwide population-based cohort study

OBJECTIVES

Despite the high prevalence of tuberculosis (TB) and the disease burden of osteoporosis and osteoporotic fractures, there is still a lack of well-designed, large-scale studies demonstrating associations among them. We aimed to investigate the effect of TB on the incidence of osteoporosis and osteoporotic fractures.

STUDY DESIGN

This was a nationwide population-based cohort study.

METHODS

This study was conducted using the National Health Insurance Service Database of South Korea. We included patients with newly diagnosed TB aged >40 years from January 2006 to December 2017. An uninfected control for each TB patient was randomly extracted by frequency matching for sex, age, income level, residence, and registration date at a 2:1 ratio. The primary outcome was the incidence of osteoporosis and osteoporotic fractures between the two groups, adjusted for sex, age, income level, residence, comorbidities, body mass index, blood pressure, laboratory tests, alcohol drinking, and smoking. The risk factors associated with osteoporosis or osteoporotic fractures were also investigated.

RESULTS

A total of 164,389 patients with TB and 328,778 matched controls were included (71.9% males). The mean duration of follow-up was 7.00 ± 3.49 years. The incidence of osteoporosis in patients with TB was 6.1 cases per 1000 person-years, which was significantly higher than that in matched controls (adjusted hazard ratio [aHR] 1.349, 95% confidence interval [CI] 1.302-1.398, P < 0.001). The incidence of osteoporotic fractures was also higher in patients with TB than in controls (aHR 1.392, 95% CI 1.357-1.428, P < 0.001). Among fractures, the risk of hip fracture was the highest (aHR 1.703, 95% CI 1.612-1.798, P < 0.001).

CONCLUSIONS

TB independently contributes to the incidence of osteoporosis and osteoporotic fractures, particularly hip fractures.

Deep Learning With Chest Radiographs for Making Prognoses in Patients With COVID-19: Retrospective Cohort Study

BACKGROUND

An artificial intelligence (AI) model using chest radiography (CXR) may provide good performance in making prognoses for COVID-19.

OBJECTIVE

We aimed to develop and validate a prediction model using CXR based on an AI model and clinical variables to predict clinical outcomes in patients with COVID-19.

METHODS

This retrospective longitudinal study included patients hospitalized for COVID-19 at multiple COVID-19 medical centers between February 2020 and October 2020. Patients at Boramae Medical Center were randomly classified into training, validation, and internal testing sets (at a ratio of 8:1:1, respectively). An AI model using initial CXR images as input, a logistic regression model using clinical information, and a combined model using the output of the AI model (as CXR score) and clinical information were developed and trained to predict hospital length of stay (LOS) ≤2 weeks, need for oxygen supplementation, and acute respiratory distress syndrome (ARDS). The models were externally validated in the Korean Imaging Cohort of COVID-19 data set for discrimination and calibration.

RESULTS

The AI model using CXR and the logistic regression model using clinical variables were suboptimal to predict hospital LOS ≤2 weeks or the need for oxygen supplementation but performed acceptably in the prediction of ARDS (AI model area under the curve [AUC] 0.782, 95% CI 0.720-0.845; logistic regression model AUC 0.878, 95% CI 0.838-0.919). The combined model performed better in predicting the need for oxygen supplementation (AUC 0.704, 95% CI 0.646-0.762) and ARDS (AUC 0.890, 95% CI 0.853-0.928) compared to the CXR score alone. Both the AI and combined models showed good calibration for predicting ARDS (P=.079 and P=.859).

CONCLUSIONS

The combined prediction model, comprising the CXR score and clinical information, was externally validated as having acceptable performance in predicting severe illness and excellent performance in predicting ARDS in patients with COVID-19.

Preoperative Chemoradiotherapy With Capecitabine With or Without Temozolomide in Patients With Locally Advanced Rectal Cancer: A Prospective, Randomised Phase II Study Stratified by O6-Methylguanine DNA Methyltransferase Status: KCSG-CO17-02

AIMS

To evaluate the clinical efficacy of adding temozolomide (TMZ) to preoperative capecitabine (CAP)-based chemoradiotherapy in patients with locally advanced rectal cancer (LARC) and validate O⁶-methylguanine DNA methyltransferase (MGMT) methylation status as a predictive marker for TMZ combined regimens.

MATERIALS AND METHODS

LARC patients with clinical stage II (cT3-4N0) or III (cT_anyN+) disease were enrolled. They were stratified into unmethylated MGMT (uMGMT) and methylated MGMT (mMGMT) groups by methylation-specific polymerase chain reaction before randomisation and were then randomly assigned (1:1) to one of four treatment arms: uMGMT/CAP (arm A), uMGMT/TMZ + CAP (arm B), mMGMT/CAP (arm C) and mMGMT/TMZ + CAP (arm D). The primary end point was the pathological complete response (pCR) rate.

RESULTS

Between November 2017 and July 2020, 64 patients were randomised. Slow accrual caused early study termination. After excluding four ineligible patients, 60 were included in the full analysis set. The pCR rate was 15.0% (9/60), 0%, 14.3%, 18.8% and 26.7% for the entire cohort, arms A, B, C and D, respectively (P = 0.0498 between arms A and D). The pCR rate was 9.7% in the CAP group (arms A + C), 20.7% in the TMZ + CAP group (arms B + D), 6.9% in the uMGMT group (arms A + B) and 22.6% in the mMGMT group (arms C + D). Grade 1-2 nausea or vomiting was significantly more frequent in the TMZ + CAP treatment groups (arms B + D) than in the CAP treatment groups (arms A + C, P < 0.001) with no difference in grade 3 adverse events. There were no grade 4 or 5 adverse events.

CONCLUSION

The addition of TMZ to CAP-based chemoradiotherapy tended to improve pCR rates, particularly in those with mMGMT LARC. MGMT status may warrant further investigation as a predictive biomarker for chemotherapeutic agents and radiotherapy.

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.

Evaluation of the efficacy and safety of NVP-1203 and aceclofenac in patients with acute low back pain and muscle spasm: A randomized, double-blind, active-controlled, parallel, multicenter, phase 3 clinical trial

OBJECTIVE

Acute low back pain (LBP) is a common condition that can be chronic if not properly treated. Aceclofenac and eperisone hydrochloride are commonly prescribed drugs for acute LBP and muscle spasms. Therefore, NVP-1203, a fixed-dose combination of 100 mg aceclofenac and 75 mg eperisone hydrochloride, is being developed. This study aimed to evaluate the efficacy and safety of NVP-1203 compared to those of a single administration of 100 mg aceclofenac in patients with acute LBP and muscle spasms.

PATIENTS AND METHODS

Overall, 455 patients with acute LBP and muscle spasms were enrolled. The patients were assigned to NVP-1203 or Airtal group (aceclofenac 100 mg). The primary efficacy endpoint was the mean change in the 100 mm pain movement and resting visual analog scale (VAS) scores on treatment day 7.

RESULTS

The mean change in the 100 mm pain movement/resting VAS scores from baseline to day 7 was -49.7 ± 21.5/-41.0 ± 19.4 mm and -38.8 ± 18.9/-33.8 ± 18.0 mm for the NVP-1203 and Airtal groups, respectively. The differences between the two groups were statistically significant (movement, p < 0.0001; resting, p = 0.0002). Differences in least-square (LS) mean change of the 100 mm pain movement/resting VAS score between the two groups using the analysis of covariance (ANCOVA) model was -10.2/-7.4 mm, and the upper limit of the 95% confidence interval was -6.44/-4.16 mm.

CONCLUSIONS

NVP-1203 is more effective in reducing pain than the 100 mg aceclofenac alone. However, the two drugs have similar safety profiles in patients with acute LBP and muscle spasms.

Comparing the efficacy of different methods of faecal microbiota transplantation via oral capsule, oesophagogastroduodenoscopy, colonoscopy, or gastric tube

BACKGROUND

The increasing prevalence of multidrug-resistant organism (MDRO) carriage poses major challenges to medicine as healthcare costs increase. Recently, faecal microbiota transplantation (FMT) has been discussed as a novel and effective method for decolonizing MDRO.

AIM

To compare the efficacy of different FMT methods to optimize the success rate of decolonization in patients with MDRO carriage.

METHODS

This prospective cohort study enrolled patients with MDRO carriages from 2018 to 2021. Patients underwent FMT via one of the following methods: oral capsule, oesophagogastroduodenoscopy (EGD), colonoscopy, or gastric tube.

FINDINGS

A total of 57 patients underwent FMT for MDRO decolonization. The colonoscopy group required the shortest time for decolonization, whereas the EGD group required the longest (24.9 vs 190.4 days, P = 0.022). The decolonization rate in the oral capsule group was comparable to that in the EGD group (84.6% vs 85.7%, P = 0.730). An important clinical factor associated with decolonization failure was antibiotic use after FMT (odds ratio = 6.810, P = 0.008). All four groups showed reduced proportions of MDRO species in microbiome analysis after FMT.

CONCLUSION

Compared to other conventional methods, the oral capsule is an effective FMT method for patients who can tolerate an oral diet. The discontinuation of antibiotics after FMT is a key factor in the success of decolonization.

Absolute Bed Rest Duration of 3 Days for Osteoporotic Vertebral Fractures: A Retrospective Study

STUDY DESIGN

Retrospective case-control study.

PURPOSE

To reduce unnecessary absolute bed rest (ABR), this study sought to determine the optimal aimed length of ABR in older patients getting conservative treatment for osteoporotic vertebral fractures (OVFs).

OVERVIEW OF LITERATURE

OVFs are quite common in elderly patients. ABR is a vital part of conservative treatment for OVFs, although the length of ABR may increase patient. No recommendations regarding how long ABR should last.

METHODS

This study was conducted in 134 patients with OVFs initially treated conservatively. The patients were split into two groups: 3-day and 7-day ABR. From the time of injury to 1, 4, and 12 weeks after injury, compression rate (CR) and local kyphotic angle (LKA) were assessed and compared between the two groups. Any complications such as pneumonia, deep vein thrombosis, delirium, and urinary tract infection known to be related to ABR were examined based on the electronic medical record.

RESULTS

Forty-four patients underwent ABR for 3 days and 90 underwent ABR for 7 days. There was no significant difference in CR and LKA between the two groups at the time of injury versus 1, 4, and 12 weeks after injury. The patients were divided into two groups: those who received a 3-day ABR and those who received a 7-day ABR. CR and LKA were measured and compared between the two groups from the time of damage to 1, 4, and 12 weeks after injury. The ABR-related complication rate was 43.4% in the 7-day ABR group and 22.7% in 3-day ABR group (p=0.02). The duration of hospital stay was significantly shorter in the 3-day ABR group (12.8 days) than in the 7-day group (16 days) (p=0.01).

CONCLUSIONS

Considering radiological outcomes, prognosis, complications, patient convenience, and economic impact, a 3-day ABR period is appropriate for the conservative treatment of OVFs.

Forearm bone mineral density as a predictor of reduction loss in distal radius fractures treated with cast immobilization

Objective

Many potential predictors have been identified and proposed for predicting late reduction loss in distal radius fractures. However, no report exists on whether the bone mineral density (BMD) of the forearm correlates with the loss of reduction in distal radius fractures. This study aimed to investigate whether forearm BMD can be used as a predictor of reduction loss in distal radius fractures treated with cast immobilization.

Methods

Ninety patients with distal radius fractures were divided into two groups according to the maintenance or loss of reduction evaluated from radiographs taken at least 6 weeks after their injury. Lumbar and forearm BMD (total and metaphysis) T-scores were measured and compared between the maintenance of reduction (MOR) group and the loss of reduction (LOR) group. Additionally, serologic markers (C-terminal telopeptide, osteocalcin, vitamin D) and radiologic risk factors (intra-articular fracture, ulnar fracture, dorsal comminuted fracture, volar hook) were evaluated and a logistic multiple regression analysis was performed to know the main risk factors of reduction loss.

Results

Reduction loss was observed in 38 patients (42.2%). The total and metaphyseal BMD of the forearm was less in the LOR group than in the MOR group. However, the difference was not statistically significant [−2.9 vs. −2.5 for total (p = 0.18), −2.3 vs. −2.0 for metaphysis (p = 0.17)]. Multiple logistic regression analysis showed initial dorsal comminution (p = 0.008) and ulnar variance (p = 0.01) were the main risk factors for reduction loss.

Conclusions

Forearm BMD was not a valuable prognostic factor for reduction loss in distal radius fractures. Initial dorsal comminution and ulnar variance rather than forearm BMD should be considered preferentially when predicting which patients are at high risk of reduction loss in distal radius fractures.

The global burden of sudden infant death syndrome from 1990 to 2019: a systematic analysis from the Global Burden of Disease study 2019

BACKGROUND

Sudden infant death syndrome (SIDS) still remains one of the leading causes of infant death worldwide, especially in high-income countries. To date, however, there is no detailed information on the global health burden of SIDS.

AIMS

To characterize the global disease burden of SIDS and its trends from 1990 to 2019 and to compare the burden of SIDS according to the socio-demographic index (SDI).

DESIGN

Systematic analysis based on the Global Burden of Disease (GBD) 2019 data.

METHODS

Epidemiological data of 204 countries from 1990 to 2019 were collected via various methods including civil registration and vital statistics in the original GBD study. Estimates for mortality and disease burden of SIDS were modeled. Crude mortality and mortality rates per 100 000 population were analyzed. Disability-adjusted life years (DALYs) and DALY rates were also assessed.

RESULTS

In 2019, mortality rate of SIDS accounted for 20.98 [95% Uncertainty Interval, 9.15-46.16] globally, which was a 51% decrease from 1990. SIDS was most prevalent in Western sub-Saharan Africa, High-income North America and Oceania in 2019. The burden of SIDS was higher in males than females consistently from 1990 to 2019. Higher SDI and income level was associated with lower burden of SIDS; furthermore, countries with higher SDI and income had greater decreases in SIDS burden from 1990 to 2019.

CONCLUSIONS

The burden of SIDS has decreased drastically from 1990 to 2019. However, the improvements have occurred disproportionately between regions and SDI levels. Focused preventive efforts in under-resourced populations are needed.

The long-term cardiac events after coronary bifurcation stenting with second-generation drug-eluting stents in elderly patients are comparable to those of younger patients

Background

Elderly patients undergoing percutaneous coronary intervention (PCI) generally have a high risk of adverse clinical outcomes. We investigated the long-term clinical impact of PCI on coronary bifurcation disease in elderly patients in Korea and Italy.

Methods

From the BIFURCAT (comBined Insights from the Unified RAIN and COBIS bifurcAtion regisTries) data, we evaluated 5,537 patients who underwent PCI for coronary bifurcation disease. The primary outcome was major adverse cardiac events (MACEs), defined as the composite of target vessel myocardial infarction, target lesion revascularisation, and stent thrombosis. Kaplan–Meier estimates and Cox proportional hazard models were used to compare elderly patients (aged ≥75 years) and younger patients (aged &lt;75 years).

Results

A total of 1,415 patients (26%) were aged ≥75 years. Elderly patients were more frequently female, had higher rates of hypertension and chronic kidney disease (CKD), and presented more frequently with left main (LM) disease. After a median follow-up of 2.1 years, MACEs were comparable between elderly and younger patients. In multivariable analysis, old age was not an independent predictor of MACEs (p=0.977). In elderly patients, CKD and LM disease were independent predictors of MACEs, whereas in younger patients, hypertension, diabetes, CKD, reduced left ventricular ejection fraction, LM disease, and two-stent strategy usage were independent predictors.

Conclusions

Elderly patients who underwent coronary bifurcation PCI with second-generation drug-eluting stents demonstrated similar clinical outcomes to those of younger patients. Both CKD and LM disease were independent predictors of MACEs, regardless of age after coronary bifurcation PCI.

Funding Acknowledgement

Type of funding sources: None.

The differential effects of antihypertensive drugs on central blood pressure: nebivolol versus telmisartan (ATD-CBP)

Background

Central blood pressure and central pulse pressure have a better correlation with the risk of cardiovascular disease compared to those of peripheral measurement. In a previous study, a second-generation beta-blocker showed poor CBP-lowering effects. However, the effect on CBP by third-generation beta-blockers is not fully elucidated. Thus, this randomised study investigated whether nebivolol-based hypertension treatment may confer advantages over telmisartan, an angiotensin II receptor-blocker, in reducing CBP.

Methods

This was a prospective, randomised, multicentre, open-label, controlled trial that evaluated 98 hypertensive patients. Patients received either nebivolol- (N=49) or telmisartan-based (N=49) treatment for hypertension for 12 weeks with a target BP of ≤140/80. The primary outcome was the difference in change from baseline central systolic BP (cSBP) after 12 weeks.

Results

There were no significant differences between the two groups in baseline central and peripheral SBP. The mean change in cSBP from baseline (ΔcSBP) was −17.2±3 mmHg for nebivolol group (P&lt;0.001) and −29.9±3 mmHg for telmisartan group (P&lt;0.001). The difference in ΔcSBP between the two groups was significant (12.7mmHg, 95% confidence interval [CI], 4.13 to 21.2; P=0.004). Peripheral SBP (pSBP) decreased less in nebivolol group compared to telmisartan group (−18.0±3 in nebivolol group vs. −26.3±3 in telmisartan group, P=0.032). After adjusting for reduction in pSBP, reduction in cSBP was higher in telmisartan group compared to nebivolol group, as shown by the ratio of changes in cSBP and pSBP (ΔcSBP/ΔpSBP; 0.67 for nebivolol group vs. 1.11 for telmisartan group, P=0.080), albeit without statistical significance.

Conclusions

Nebivolol-based hypertension treatment may have less potent CBP-lowering effects compared to telmisartan. However, larger-scale studies are warranted to further elaborate our findings.

Funding Acknowledgement

Type of funding sources: None.

Effect of an early invasive strategy based on time of symptom onset in patients with non-ST elevation myocardial infarction

Background

A limitation of the current guidelines of the timing of invasive coronary angiography (ICA) for patients with non-ST-segment elevation (NSTE) acute coronary syndrome is based on randomization time. So far, no study has reported the clinical outcomes of invasive strategy timing based on the time of symptom onset. Herein, we aimed to investigate the effect of invasive strategy timing from the time of symptom onset on the 3-year clinical outcomes of patients with NSTE myocardial infarction (MI).

Methods and results

Among 13,104 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health, we evaluated 5,856 patients with NSTEMI. The patients were categorized according to symptom-to-catheter (StC) time (&lt;48 h and ≥48 h). The primary outcome was 3-year all-cause mortality, and the secondary outcome was a 3-year composite of all-cause mortality, recurrent MI, and hospitalization for heart failure. Overall, 3,919 (66.9%) patients were classified into the StC time &lt;48 h group. This group had lower all-cause mortality than the StC time ≥48 h group (7.3% vs. 13.4%, p&lt;0.001). The continuous association of StC time and risk of primary and secondary endpoints showed shorter StC time (reference: 48 h), and lower adjusted hazard ratio reduction was observed. In multivariable analysis, independent predictors of delayed ICA were older age, non-specific symptoms, no use of emergency medical services, no ST-segment deviation, chronic kidney disease, and Global Registry of Acute Coronary Events score &gt;140.

Conclusion

Early invasive strategy based on the StC time improves all-cause mortality in patients with NSTEMI.

Funding Acknowledgement

Type of funding sources: None.

Risk factors and clinical effects of late leaflet thrombosis after transcatheter aortic valve replacement

Background

As the indications for trans-catheter aortic valve replacement (TAVR) expand, it is expected that the number of TAVR patients would increase and the follow-up duration would be longer. It is known that the incidence of leaflet thrombosis is higher in TAVR than in surgical aortic valve replacement (SAVR), but not much is known about the risk factors of late leaflet thrombosis in TAVR.

Aim

Therefore, in this study, the incidence and risk factors of late leaflet thrombosis at late term after TAVR and the effect on clinical course of late leaflet thrombosis would be investigated.

Method

There were 176 patients undergone TAVR from January 2015 to October 2020 in one tertiary hospital of south korea. 94 patients had follow-up cardiovascular computed tomography (CT) between 3 months and 2 years after TAVR. Among 94 patients, late leaflet thrombosis was discovered at 20 patients, and risk factors were analyzed by comparing clinical factors, echocardiographic and cardiovascular CT information, and angiographic data between the group with and without late leaflet thrombosis. And the difference in aortic valve hemodynamics between the group with and without leaflet thrombosis was examined and clinical outcomes were compared. Clinical outcome was defined as the composite of all-cause death, stroke, heart failure (HF) admission, redo-aortic valve (AV) replacement and major bleeding after detection of late leaflet thrombosis.

Results

Indexed mean sinus of Valsalva diameter, AV calcium score and post procedure estimated orifice area (EOA) had predictability of late leaflet thrombosis with AUC value of 0.670 (95% CI [0.546–0.795], p value = 0.020), AUC value of 0.698 (95% CI [0.544–0.851], p value = 0.012) and AUC value of 0.665 (95 percent CI [0.548–0.782], p value = 0.031), respectively (Figure 1).

In echocardiography performed at the time of follow-up CT, AV max velocity and AV mean pressure gradient were higher in thrombosis group and EOA and Doppler velocity index were lower in thrombosis group than in no thrombosis group within normal range (Figure 2). Clinical outcome was not significant different between the two groups (log rank p value = 0.560).

Conclusion

Larger indexed sinus of Valsalva diameter, higher AV calcium score and smaller post procedure AV EOA were risk factors for late leaflet thrombosis after TAVR. Subclinical late leaflet thrombosis have a benign course when properly managed.

Funding Acknowledgement

Type of funding sources: None.

In Vitro Analysis of the Efficacy of Endovascular Thrombectomy Techniques according to the Vascular Tortuosity Using 3D Printed Models

BACKGROUND AND PURPOSE

Achieving complete recanalization with the front-line endovascular thrombectomy device improves the outcome of acute stroke. The aim of this study was to evaluate whether various thrombectomy techniques including contact aspiration, stent retriever thrombectomy, and combination therapy differ in first-pass effect and distal emboli in acute large-vessel occlusion simulated using 3D printed nontortuous and tortuous cerebrovascular anatomy models.

MATERIALS AND METHODS

3D printed flow models were manufactured using angiographic data of nontortuous and acutely angulated tortuous vascular anatomy from real patients. Three thrombectomy techniques, contact aspiration, stent retriever, and combined methods, were tested under proximal protection with the balloon-guiding catheter. The first-pass effect and distal emboli rates were analyzed in addition to the thrombectomy-failure mechanisms of the respective techniques.

RESULTS

A total of 30 thrombectomy experiments were performed. The overall incidence of first-pass effect in the nontortuous and tortuous anatomy was 80.0% versus 46.7%. The overall incidence of distal emboli in the nontortuous and tortuous anatomy was 26.7% versus 46.7%. The contact aspiration technique showed better first-pass effect (80.0%) and distal emboli rates (20%) in the tortuous model compared with other techniques. The combined technique did not show remarkable superiority of the first-pass effect and distal emboli in either the nontortuous or tortuous anatomy. Shearing off of the thrombus was the main mechanism of thrombectomy failure in the combined group.

CONCLUSIONS

The tortuous vascular anatomy may worsen the first-pass effect and distal emboli rates. The combined techniques failed to show improvement in outcome due to the shearing-off phenomenon of the thrombus during retrieval.

Radiological Characteristics of Low-Grade Lytic Spondylolisthesis: Similarity to Dysplastic Spondylolisthesis

Study Design

Retrospective case-control study.

Purpose

This study aimed to analyze the etiology of low-grade lytic spondylolisthesis based on the radiologic features of the vertebra.

Overview of Literature

According to the Marchetti-Bartolozzi classification scheme, high-grade lytic spondylolisthesis (Meyerding grade 3-5) is classified as dysplastic. However, determination of the etiology for low-grade lytic spondylolisthesis as developmental or traumatic remains controversial.

Methods

Patients admitted and treated for one-level (L4/5 or L5/S1) low-grade spondylolisthesis were included in the study. A total of 135 patients were divided into the degenerative or lytic spondylolisthesis groups according to their condition (81 patients [degenerative group] vs. 54 patients [lytic group]). To assess the level of similarity in the radiological findings between low-grade lytic spondylolisthesis and dysplastic spondylolisthesis, the pedicle diameters and vertebral heights of the L4 and L5 vertebrae were measured on computed tomography images. Measurements were then converted to each vertebra's ratio to reduce confounding factors among individuals.

Results

The affected vertebra had a smaller sagittal pedicle diameter/transverse pedicle diameter ratio in the low-grade lytic spondylolisthesis group compared to the degenerative group, and the posterior vertebral height/anterior vertebral height ratio of L5 was smaller in the L5/S1 lytic spondylolisthesis group compared to the degenerative spondylolisthesis group.

Conclusions

Low-grade lytic spondylolisthesis and dysplastic spondylolisthesis demonstrated similar radiological findings. Hence, surgeons should be attentive to the morphology of the vertebral body and posterior column during preoperative planning for the treatment of low-grade lytic spondylolisthesis.

Evaluation of the MolecuTech® REBA MTB-XMDR kit for detection of pre-extensively drug-resistant TB

BACKGROUND: Rapid diagnosis of drug-resistant TB is critical for early initiation of effective therapy. YD Diagnostics in South Korea recently developed the MolecuTech^® REBA MTB-XMDR test to rapidly detect multidrug-resistant TB (MDR-TB), pre-extensively drug-resistant TB (pre-XDR-TB) and resistance to second-line injectable drugs (SLIDs) simultaneously using a fully automated test platform. This study aimed to evaluate the MolecuTech^® test for the detection of MDR- and pre-XDR-TB, as well as SLID resistance.METHODS: A total of 151 clinical Mycobacterium tuberculosis isolates from South Korea were tested using the MolecuTech test, and the results were analysed by comparing these with phenotypic drug susceptibility testing (pDST) and sequencing.RESULTS: Compared to pDST, the MolecuTech test showed a sensitivity and specificity of respectively 97.7% and 100.0% for rifampicin (RIF), 82.4% and 100.0% for isoniazid (INH), 97.5% and 97.2% for fluoroquinolones (FQs), and 94.0% and 98.8% for SLIDs. Concordances with the sequencing results of each resistance determinant were 99.3% for RIF, 96.7% for INH, 98.7% for FQs and 99.3% for SLIDs.CONCLUSION: The MolecuTech test is an efficient and reliable rapid molecular diagnostic tool for the simultaneous screening of MDR- and pre-XDR-TB.

Predictors and Impact of Sulcal SAH after Mechanical Thrombectomy in Patients with Isolated M2 Occlusion

BACKGROUND AND PURPOSE

Data on SAH after M2 mechanical thrombectomy are limited. We aimed to determine the prevalence of sulcal SAH after mechanical thrombectomy for M2 occlusion, its associated predictors, and the resulting clinical outcome.

MATERIALS AND METHODS

The study retrospectively reviewed the data of patients with acute ischemic stroke who underwent mechanical thrombectomy for isolated M2 occlusion. The patients were divided into 2 groups according to the presence of sulcal SAH after M2 mechanical thrombectomy. Angiographic and clinical outcomes were compared. Multivariable analysis was performed to identify independent predictors of sulcal SAH and unfavorable outcome (90-day mRS, 3-6).

RESULTS

Of the 209 enrolled patients, sulcal SAH was observed in 33 (15.8%) patients. The sulcal SAH group showed a higher rate of distal M2 occlusion (69.7% versus 22.7%), a higher of rate of superior division occlusion (63.6% versus 43.8%), and a higher M2 angulation (median, 128° versus 106°) than the non-sulcal SAH group. Of the 33 sulcal SAH cases, 23 (66.7%) were covert without visible intraprocedural contrast extravasation. Distal M2 occlusion (OR, 12.04; 95% CI, 4.56-35.67; P < .001), superior division (OR, 3.83; 95% CI, 1.43-11.26; P = .010), M2 angulation (OR, 1.02; 95% CI, 1.01-1.04; P < .001), and the number of passes (OR, 1.58; 95% CI, 1.22-2.09; P < .001) were independent predictors of sulcal SAH. However, covert sulcal SAH was not associated with an unfavorable outcome (P = .830).

CONCLUSIONS

After mechanical thrombectomy for M2 occlusion, sulcal SAH was not uncommon and occurred more frequently with distal M2 occlusion, superior division, acute M2 angulation, and multiple thrombectomy passes (≥3). The impact of covert sulcal SAH was mostly benign and was not associated with an unfavorable outcome.

Search for Resonances Decaying to Three W Bosons in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for resonances decaying into a W boson and a radion, where the radion decays into two W bosons, is presented. The data analyzed correspond to an integrated luminosity of 138  fb^{-1} recorded in proton-proton collisions with the CMS detector at sqrt[s]=13  TeV. One isolated charged lepton is required, together with missing transverse momentum and one or two massive large-radius jets, containing the decay products of either two or one W bosons, respectively. No excess over the background estimation is observed. The results are combined with those from a complementary channel with an all-hadronic final state, described in an accompanying paper. Limits are set on parameters of an extended warped extra-dimensional model. These searches are the first of their kind at the LHC.

Probing Charm Quark Dynamics via Multiparticle Correlations in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Multiparticle azimuthal correlations of prompt D^{0} mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02  TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v_{2}) of D^{0} mesons as a function of event centrality and the D^{0} transverse momentum. The ratios of the four-particle v_{2} values to previously measured two-particle cumulant results provide direct experimental access to event-by-event fluctuations of charm quark azimuthal anisotropies. These ratios are also found to be comparable to those of inclusive charged particles in the event. However, hints of deviations are seen in the most central and peripheral collisions. To investigate the origin of flow fluctuations in the charm sector, these measurements are compared to a model implementing fluctuations of charm quark energy loss via collisional or radiative processes in the quark-gluon plasma. These models cannot quantitatively describe the data over the full transverse momentum and centrality ranges, although the calculations with collisional energy loss provide a better description of the data.

Self-evolving vision transformer for chest X-ray diagnosis through knowledge distillation

Although deep learning-based computer-aided diagnosis systems have recently achieved expert-level performance, developing a robust model requires large, high-quality data with annotations that are expensive to obtain. This situation poses a conundrum that annually-collected chest x-rays cannot be utilized due to the absence of labels, especially in deprived areas. In this study, we present a framework named distillation for self-supervision and self-train learning (DISTL) inspired by the learning process of the radiologists, which can improve the performance of vision transformer simultaneously with self-supervision and self-training through knowledge distillation. In external validation from three hospitals for diagnosis of tuberculosis, pneumothorax, and COVID-19, DISTL offers gradually improved performance as the amount of unlabeled data increase, even better than the fully supervised model with the same amount of labeled data. We additionally show that the model obtained with DISTL is robust to various real-world nuisances, offering better applicability in clinical setting.

Although deep learning-based computer-aided diagnosis systems have recently achieved expert level performance, developing a robust model requires large, high-quality data with annotations. Here, the authors present a framework which can improve the performance of vision transformer simultaneously with self-supervision and self-training.