[Clinical characteristics and outcomes of acute respiratory distress syndrome caused by severe Chlamydia psittaci pneumonia]

Objective: To investigate the clinical characteristics and outcomes of acute respiratory distress syndrome (ARDS) caused by Chlamydia psittaci pneumonia. Methods: From June 2016 to January 2021, 10 cases were diagnosed as severe Chlamydia psittaci pneumonia induced ARDS in Intensive Care Unit of Respiratory and Critical Care Medicine Department (RICU) of Beijing Chao-Yang Hospital Affiliated to Capital Medical University. We collected the clinical data including clinical features, laboratory tests, imaging and outcomes of the patients. Results: The pathogenic diagnosis was confirmed by metagenomic Next-generation Sequencing (mNGS) in these 10 patients, with a median age of 59 (46, 67) years. In addition to high fever, cough and dyspnea, the patients also had multiple organ involvement. Six patients had elevated peripheral leukocyte count, 10 cases had increased type B natriuretic peptide, 7 cases had increased aspartate aminotransferase/alanine aminotransferase, 9 cases had hyponatremia and 3 cases had elevated creatinine. The imaging findings were bilateral consolidation with air bronchogram and infiltrates, and pleural effusion were found in 5 cases. All cases were combined with respiratory failure. Six patients received invasive mechanical ventilation. Nine patients received moxifloxacin and one patient was administrated with Azithromycin. All the patients were improved and discharged after the treatment, and the mean duration of RICU stay was 13.5 (11, 16.7) days. One month follow-up of nine patients showed significant improvement in lung lesions. Conclusions: Severe Chlamydia psittiaci pneumonia may be complicated with respiratory failure and/or multiple organ involvement. For severe pneumonia with an exposure history of sick birds, the possibility of Chlamydia psittaci infection should be considered. mNGS may help etiological diagnosis. All patients in this study had a good prognosis after targeted treatment.

Simulation-Free Radiation Therapy: An Emerging Form of Treatment Planning to Expedite Plan Generation for Patients Receiving Palliative Radiation Therapy

Purpose

Herein we report the clinical and dosimetric experience for patients with metastases treated with palliative simulation-free radiation therapy (SFRT) at a single institution.

Methods and Materials

SFRT was performed at a single institution. Multiple fractionation regimens were used. Diagnostic imaging was used for treatment planning. Patient characteristics as well as planning and treatment time points were collected. A matched cohort of patients with conventional computed tomography simulation radiation therapy (CTRT) was acquired to evaluate for differences in planning and treatment time. SFRT dosimetry was evaluated to determine the fidelity of SFRT. Descriptive statistics were calculated on all variables and statistical significance was evaluated using the Wilcoxon signed rank test and t test methods.

Results

Thirty sessions of SFRT were performed and matched with 30 sessions of CTRT. Seventy percent of SFRT and 63% of CTRT treatments were single fraction. The median time to plan generation was 0.88 days (0.19-1.47) for SFRT and 1.90 days (0.39-5.23) for CTRT (P = .02). The total treatment time was 41 minutes (28-64) for SFRT and 30 minutes (21-45) for CTRT (P = .02). In the SFRT courses, the maximum and mean deviations in the actual delivered dose from the approved plans for the maximum dose were 4.1% and 0.07%, respectively. All deliveries were within a 5% threshold and deemed clinically acceptable.

Conclusions

Palliative SFRT is an emerging technique that allowed for a statistically significant lower time to plan generation and was dosimetrically acceptable. This benefit must be weighed against increased total treatment time for patients receiving SFRT compared with CTRT, and appropriate patient selection is critical.

A multi-layer strip ionization chamber (MLSIC) device for proton pencil beam scan quality assurance

Objective. Proton pencil beam scanning (PBS) treatment fields needs to be verified before treatment deliveries to ensure patient safety. In current practice, treatment beam quality assurance (QA) is measured at a few selected depths using film or a 2D detector array, which is insensitive and time-consuming. A QA device that can measure all key dosimetric characteristics of treatment beams spot-by-spot within a single beam delivery is highly desired.Approach. We developed a multi-layer strip ionization chamber (MLSIC) prototype device that comprises of two layers of strip ionization chambers (IC) plates for spot position measurement and 64 layers of plate IC for beam energy measurement. The 768-channel strip ion chamber signals are integrated and sampled at a speed of 3.125 kHz. It has a 25.6 cm × 25.6 cm maximum measurement field size and 2 mm spatial resolution for spot position measurement. The depth resolution and maximum depth were 2.91 mm and 18.6 cm for 1.6 mm thick IC plate, respectively. The relative weight of each spot was determined from total charge by all IC detector channels.Main results. The MLSIC is able to measure ionization currents spot-by-spot. The depth dose measurement has a good agreement with the ground truth measured using a water tank and commercial one-dimensional (1D) multi-layer plate chamber. It can verify the spot position, energy, and relative weight of clinical PBS beams and compared with the treatment plans.Significance. The MLSIC is a highly efficient QA device that can measure the key dosimetric characteristics of proton treatment beams spot-by-spot with a single beam delivery. It may improve the quality and efficiency of clinical proton treatments.

Vented Individual Patient (VIP) Hoods for the Control of Infectious Airborne Diseases in Healthcare Facilities

By providing a means of separating the airborne emissions of patients from the air breathed by healthcare workers (HCWs), vented individual patient (VIP) hoods, a form of local exhaust ventilation (LEV), offer a new approach to reduce hospital-acquired infection (HAI). Results from recent studies have demonstrated that, for typical patient-emitted aerosols, VIP hoods provide protection at least equivalent to that of an N95 mask. Unlike a mask, hood performance can be easily monitored and HCWs can be alerted to failure by alarms. The appropriate use of these relatively simple devices could both reduce the reliance on personal protective equipment (PPE) for infection control and provide a low-cost and energy-efficient form of protection for hospitals and clinics. Although the development and deployment of VIP hoods has been accelerated by the coronavirus disease 2019 (COVID-19) pandemic, these devices are currently an immature technology. In this review, we describe the state of the art of VIP hoods and identify aspects in need of further development, both in terms of device design and the protocols associated with their use. The broader concept of individual patient hoods has the potential to be expanded beyond ventilation to the provision of clean conditions for individual patients and personalized control over other environmental factors such as temperature and humidity.

[Novel MFN2, BSCL2 and LRSAM1 variants in a cohort of Chinese patients with Charcot-Marie-Tooth disease]

Objective: Charcot-Marie-Tooth disease (CMT) comprises a group of clinically and genetically heterogeneous inherited neuropathies with an estimated prevalence of 1 in 2500. This study aimed to analyze the clinical and mutational characteristics of Chinese CMT patients with MFN2, BSCL2 and LRSAM1 variants. Methods: In this study, genetic analysis was performed in 206 Chinese patients at Chinese PLA General Hospital from December 2012 to March 2020 with clinical diagnosis of CMT, and reported variants of MFN2, BSCL2 and LRSAM1 related to CMT2. Results: We reported ten MFN2 mutations in ten unrelated patients (7 male, 3 female), two of whom had positive family history. Three novel mutations were detected including c.475-2A>G (splicing); c.687dupA (p.E230Rfs*16) and c.558dupT (p.S186fs). We reported three BSCL2 mutations of four unrelated patients, including c.461C>G (p.S154W), c.461C>T(p.S154L), and novel variants of c.1309G>C (p.A437P) and c.845C>T (p.A282V). Furthermore, two novel variants of LRSAM1, including c.1930G>T (p.G644C) and c.1178T>A (p.L393Q) were detected in two unrelated patients. Conclusion: Mutational spectrum of MFN2-, BSCL2-and LRSAM1-related CMT disease is expanded with the identification of novel variants in Chinese patients.

[Analysis of China's influenza vaccine application policy based on the macro model of the health system]

This article uses the analysis framework of the macro model of the health system to analyze the influenza vaccine policy documents issued by the state and governments at all levels from three perspectives: structure, process and results, and provides a scientific basis for improving the application strategy of influenza vaccine. It is suggested that on the basis of continuing to strengthen publicity, mobilization and organizational guarantee, measures to promote the application of influenza vaccine in China by exploring multi-channel financing mechanisms, combining the experience of new crown vaccination to improve the convenience of influenza vaccination, and scientifically setting vaccination rate targets, improve preparedness for an influenza pandemic.

[Weaning of veno-venous extracorporeal membrane oxygenation: when to use the "resting lung"]

Differences in weaning strategies for veno-venous extracorporeal membrane oxygenation (VV-ECMO) are based on expert opinions rather than clinical evidence. Therefore, each center has its own "unique skills". The timing of VV-ECMO weaning has not received due attention. It is difficult to find research on the choice of VV-ECMO weaning timing in the database. There are few studies involving VV-ECMO that describe the weaning process in detail. At present, the weaning process of VV-ECMO is mainly based on expert opinions. This article classified the current VV-ECMO weaning strategies, appealed to a unified VV-ECMO weaning protocol in China as soon as possible, and further improved the prognosis of patients with extracorporeal life support.

[Treatment choices for infected pancreatic necrosis:surgery debridement or endoscopy drainage?]

Infected pancreatic necrosis (IPN) is a crucial reason for the poor prognosis of patients with acute pancreatitis,which is complicated and difficult to predict the outcomes. Surgery is an important way to cure IPN,and "step-up approach" is the mainstream mode of IPN treatment. In the era of minimally invasive surgery,the full course endoscopic treatment of IPN has been gradually hot and achieved good outcomes as endoscopic technology' improvement. However,it is controversial that whether technique is better for IPN by surgery debridement or endoscopy drainage,and there is no consensus on the scope of applicability and the timing of intervention. The paper aims to explore the intervention methods,indications and timing of endoscopic and surgical treatment of IPN and elaborate the selection strategies of them in clinical practice,so as to develop individualized treatment options,accurately implement minimally invasive intervention and improve the prognosis.

Synchronized high-speed scintillation imaging of proton beams, generated by a gantry-mounted synchrocyclotron, on a pulse-by-pulse basis

BACKGROUND

With the emergence of more complex and novel proton delivery techniques, there is a need for quality assurance (QA) tools with high spatiotemporal resolution to conveniently measure the spatial and temporal properties of the beam. In this context, scintillation-based dosimeters, if synchronized with the radiation beam and corrected for ionization quenching, are appealing.

PURPOSE

To develop a synchronized high-speed scintillation imaging system for characterization and verification of the proton therapy beams on a pulse-by-pulse basis.

MATERIALS AND METHODS

A 30 cm × 30 cm × 5 cm block of BC-408 plastic scintillator placed in a light-tight housing was irradiated by proton beams generated by a Mevion S250^TM proton therapy synchrocyclotron. A high-speed camera system, placed perpendicular to the beam direction and facing the scintillator, was synchronized to the accelerator's pulses to capture images. Opening and closing of the camera's shutter was controlled by setting a proper time delay and exposure time, respectively. The scintillation signal was recorded as a set of two-dimensional (2D) images. Empirical correction factors were applied to the images to correct for the non-uniformity of the pixel sensitivity and quenching of the scintillator. Proton range and modulation were obtained from the corrected images.

RESULTS

The camera system was able to capture all data on a pulse-by-pulse basis at a rate of ∼504 frames per second. The applied empirical correction method for ionization quenching was effective and the corrected composite image provided a 2D map of dose distribution. The measured range (depth of distal 90%) through scintillation imaging agreed within 1.2 mm with that obtained from ionization chamber measurement.

CONCLUSION

A high-speed camera system capable of capturing scintillation signals from individual proton pulses was developed. The scintillation imaging system is promising for rapid proton beam characterization and verification. This article is protected by copyright. All rights reserved.

[SWOT analysis of influenza vaccination promotion of primary care staff based on the perspective of the supplier, customer, and management]

Objective: To analyze the situation of influenza vaccination among primary healthcare workers, find out the problems, and explore the strategies and measures to promote influenza vaccination among grass-roots medical staff. Methods: From April to May 2021, key insider interviews and literature research were carried out based on the perspectives of influenza vaccine suppliers (influenza vaccine manufacturers), consumers (primary medical institutions and primary healthcare workers), and managers (governments at all levels, health administrative departments and disease prevention and control departments). The SWOT (strengths, weaknesses, opportunities, and threats) analysis technique was used to comprehensively evaluate the current situation of influenza vaccination among grass-roots healthcare workers, and a SWOT analysis matrix was established. Results: Influenza vaccination of grass-roots healthcare workers have advantages and opportunities, including primary medical and health institutions' vital influenza vaccination accessibility, influenza vaccine safety is higher, COVID-19 outbreak improves the public awareness of respiratory infectious diseases and vaccine production enthusiasm, coronavirus vaccination has strengthened the capacity of the vaccine distribution system. There are also disadvantages and threats such as the high price of influenza vaccine, insufficient supply, low awareness of influenza vaccine vaccination among grass-roots healthcare workers, lack of demand assessment mechanism on influenza vaccine, poor vaccine deployment, structural imbalance in vaccine supply in different areas, and severe vaccine waste. SWOT analysis matrix of the influenza vaccination status of grass-roots healthcare workers was established, forming dominant opportunity (SO) strategy, dominant threat (ST) strategy, inferior opportunity (WO) strategy, and inferior threat (WT) strategy. Conclusion: Measures should be taken by the supplier, the demand-side, and the management side to improve the influenza vaccine coverage rate of primary healthcare workers, but the emphasis should be on the coordination and management of the management side.

Improvement of IMRT QA prediction using imaging-based neural architecture search

PURPOSE

Machine learning has been used to predict the gamma passing rate of Intensity-modulated radiation therapy (IMRT) QA results. In this work, we applied a novel neural architecture search to automatically tune and search for the best deep neural networks instead of using hand-designed deep learning architectures.

METHOD AND MATERIALS

One hundred and eighty-two IMRT plans were created and delivered with portal dosimetry. A total of 1497 fields for multiple treatment sites were delivered and measured by portal imagers. Gamma criteria of 2%/2mm with a 5% threshold were used. Fluence maps calculated for each plan were used as inputs to a convolution neural network (CNN). Auto-Keras was implemented to search for the best CNN architecture for fluence image regression. The network morphism was adopted in the searching process, in which the base models were ResNet and DenseNet. The performance of this CNN approach was compared with tree-based machine learning models previously developed for this application, using the same data set.

RESULTS

The deep-learning-based approach had 98.3% of predictions within 3% of the measured 2%/2mm gamma passing rates with a maximum error of 3.1% and a mean absolute error of less than 1%. Our results show that this novel architecture search approach achieves comparable performance to the machine-learning-based approaches with handcrafted features.

CONCLUSIONS

We implemented a novel CNN model using imaging-based neural architecture for IMRT QA prediction. The imaging-based deep-learning method does not require manual extraction of relevant features and is able to automatically select the best network architecture. This article is protected by copyright. All rights reserved.

MiR-572 promotes the development of non-small cell lung cancer by targeting KLF2

OBJECTIVE

The aim of this study was to uncover the role of miR-572 in regulating proliferative and migratory abilities in non-small cell lung cancer (NSCLC) and the possible mechanism.

PATIENTS AND METHODS

Expression levels of miR-572 in 46 matched NSCLC and paracancerous samples were detected. The relationship between miR-572 level and clinical features of NSCLC was analyzed. Subsequently, the regulatory effects of miR-572 on proliferative and migratory abilities in lung cancer cells were assessed by functional experiments. Finally, the downstream genes of miR-572 were tested by luciferase assay, and their functions in the development of NSCLC were finally explored by rescue experiments.

RESULTS

It was found that miR-572 was upregulated in NSCLC samples. High level of miR-572 predicted high rates of lymphatic and distant metastases, as well as poor prognosis in NSCLC. Besides, the knockdown of miR-572 suppressed proliferative and migratory abilities in A549 and SPC-A1 cells. KLF2 was identified to be the downstream gene of miR-572, which was involved in the regulation of NSCLC phenotypes influenced by miR-572.

CONCLUSIONS

MiR-572 is closely linked to metastasis and prognosis in NSCLC patients, and it promotes the malignant development of NSCLC via targeting KLF2.

Determination of the electronic portal imaging device pixel‐sensitivity‐map for quality assurance applications. Part 2: Photon beam dependence

Purpose

Methods

Results

Conclusion

Determination of the electronic portal imaging device pixel‐sensitivity‐map for quality assurance applications. Part 1: Comparison of methods

Purpose

Methods

Results

Conclusion

A reconstruction approach for proton computed tomography by modeling the integral depth dose of the scanning proton pencil beam

PURPOSE

To present a proton computed tomography (pCT) reconstruction approach that models the integral depth dose (IDD) of the clinical scanning proton beam into beamlets. Using a multi-layer ionization chamber (MLIC) as the imager, the proposed pCT system and the reconstruction approach can minimize the extra ambient neutron dose and simplify the beamline design by eliminating an additional collimator to confine the proton beam.

METHODS

Monte Carlo simulation was applied to digitally simulate the IDDs of the exiting proton beams detected by the MLIC. A forward model was developed to model each IDD into the weighted sum of percentage depth doses (PDDs) of the constituent beamlets separated laterally by 1mm. The water equivalent path lengths (WEPLs) of the beamlets were determined by iteratively minimizing the squared L2-norm of the forward projected and simulated IDDs. The final WEPL values were reconstructed to pCT images, i.e., proton Stopping Power Ratio (SPR) maps, through simultaneous algebraic reconstruction technique with total variation regularization (SART-TV). The reconstruction process was tested with a digital cylindrical water-based phantom and an ICRP adult reference computational phantom. The mean of SPR within regions of interest (ROIs) and the WEPLs along 4 mm-wide beams (WEPL_4mm ) were compared to the reference values. The spatial resolution was analyzed at the edge of a cortical insert of the cylindrical phantom.

RESULTS

The percentage deviations from reference SPR were within ±1% in all selected ROIs. The mean absolute error of the reconstructed SPR was 0.33%, 0.19%, and 0.27% for the cylindrical phantom, the adult phantom at the head and lung region, respectively. The corresponding percentage deviations from reference WEPL_4mm were 0.48%±0.64%, 0.28% ± 0.48%, and 0.22% ± 0.49%. The full width at half maximum (FWHM) of the line spread function (LSF) derived from the radial edge spread function (ESF) of a cortical insert was 0.13 cm. The frequency at 10% of the modulation transfer function (MTF) was 6.38 cm^-1 . The mean signal-to-noise ratio (SNR) of all the inserts was 2.45. The mean imaging dose was 0.29 cGy and 0.25 cGy at the head and lung region of the adult phantom, respectively.

CONCLUSION

A new pCT reconstruction approach was developed by modeling the IDDs of the uncollimated scanning proton beams in the pencil beam geometry. SPR accuracy within ±1%, spatial resolution of better than 2mm at 10% MTF, and imaging dose at the magnitude of mGy were achieved. Potential side effects caused by neutron dose were eliminated by removing the extra beam collimator. This article is protected by copyright. All rights reserved.

[Clinicopathological features of verrucous hemangioma]

Objective: To investigate the clinicopathological features, and differential diagnosis of verrucous hemangioma (VH). Methods: Twenty-eight VH cases diagnosed from 2005 to 2020 in Henan Provincial People's Hospital, Zhengzhou, China were analyzed retrospectively. Immunohistochemical studies were used to detect diagnostic markers. The mutation status of PIK3CA (exons 9 and 20) was detected using fluorescence PCR. Results: There were 13 males and 15 females in 28 cases, with the male to female ratio of 1.0∶1.2. There were 25 patients under the age of 18 years. The age range was from 10 months to 56 years (mean, 9.7 years; median, 4.5 years). There were 17 cases occurred in the lower extremities, 7 in the upper extremities and 4 in the trunk. All 28 cases were irregular red patches on the skin, which grew slowly. Some of them were thickened with uneven surface, which was light pink or red-white. Skin lesions of the 7 cases ranged from dark red and reddish brown, with a rough and hard surface. Satellite foci were present. Microscopically, 28 cases had a wide range of pathological features. Dilated, malformed vessels were observed from dermal papilla to deep soft tissue. Among them, the dermal papillary layer was mainly composed of many proliferating and expanding thin-walled capillaries and cavernous blood vessels. Thin-walled small vessels were found in the dermal reticular layer and subcutaneous fascia layer, with no obvious endothelial cell proliferation, occasional papillary hyperplasia, and lobular distribution of the malformed vessels in the fascia layer mixed with the fibroadipose tissue. There was epidermal papillary hyperplasia with hyperkeratosis and parakeratosis, lengthening and mutual fusion of epithelial horns. Immunohistochemistry showed that CD31, CD34, ERG and WT-1 were diffusely and strongly positive. The expression of GLUT-1 was present in superficial dermal vascular endothelial cells, but undetectable in the deep layer. The PIK3CA tests of 13 cases showed that no somatic mutations were found in exons 9 and 20. Twenty-five patients were followed up for 5 months to 10 years. Seven patients underwent multiple surgical resections and plastic surgeries due to the large size, and 8 patients had recurrence. Conclusions: VH is a rare congenital vascular malformation and more commonly occurs in infants and children. It tends to appear in limbs, especially lower limbs and distal limbs. Its morphology and immunophenotype are characteristic and should be distinguished from other vascular malformations and the resolution phase of infant hemangiomas. In about one third of the cases, postoperative recurrence may occur and long-term follow-up is often required.

Weaving attention U-net: A novel hybrid CNN and attention-based method for organs-at-risk segmentation in head and neck CT images

PURPOSE

In radiotherapy planning, manual contouring is labor-intensive and time-consuming. Accurate and robust automated segmentation models improve the efficiency and treatment outcome. We aim to develop a novel hybrid deep learning approach, combining convolutional neural networks (CNNs) and the self-attention mechanism, for rapid and accurate multi-organ segmentation on head and neck computed tomography (CT) images.

METHODS

Head and neck CT images with manual contours of 115 patients were retrospectively collected and used. We set the training/validation/testing ratio to 81/9/25 and used the 10-fold cross-validation strategy to select the best model parameters. The proposed hybrid model segmented 10 organs-at-risk (OARs) altogether for each case. The performance of the model was evaluated by three metrics, that is, the Dice Similarity Coefficient (DSC), Hausdorff distance 95% (HD95), and mean surface distance (MSD). We also tested the performance of the model on the head and neck 2015 challenge dataset and compared it against several state-of-the-art automated segmentation algorithms.

RESULTS

The proposed method generated contours that closely resemble the ground truth for 10 OARs. On the head and neck 2015 challenge dataset, the DSC scores of these OARs were 0.91 ± 0.02, 0.73 ± 0.10, 0.95 ± 0.03, 0.76 ± 0.08, 0.79 ± 0.05, 0.87 ± 0.05, 0.86 ± 0.08, 0.87 ± 0.03, and 0.87 ± 0.07 for brain stem, chiasm, mandible, left/right optic nerve, left/right submandibular, and left/right parotid, respectively. Our results of the new weaving attention U-net (WAU-net) demonstrate superior or similar performance on the segmentation of head and neck CT images.

CONCLUSIONS

We developed a deep learning approach that integrates the merits of CNNs and the self-attention mechanism. The proposed WAU-net can efficiently capture local and global dependencies and achieves state-of-the-art performance on the head and neck multi-organ segmentation task.

Semi-supervised semantic segmentation of prostate and organs-at-risk on 3D pelvic CT images

The recent development of deep learning approaches has revoluted medical data processing, including semantic segmentation, by dramatically improving performance. Automated segmentation can assist radiotherapy treatment planning by saving manual contouring efforts and reducing intra-observer and inter-observer variations. However, training effective deep learning models usually Requires a large amount of high-quality labeled data, often costly to collect. We developed a novel semi-supervised adversarial deep learning approach for 3D pelvic CT image semantic segmentation. Unlike supervised deep learning methods, the new approach can utilize both annotated and un-annotated data for training. It generates un-annotated synthetic data by a data augmentation scheme using generative adversarial networks (GANs). We applied the new approach to segmenting multiple organs in male pelvic CT images. CT images without annotations and GAN-synthesized un-annotated images were used in semi-supervised learning. Experimental results, evaluated by three metrics (Dice similarity coefficient, average Hausdorff distance, and average surface Hausdorff distance), showed that the new method achieved comparable performance with substantially fewer annotated images or better performance with the same amount of annotated data, outperforming the existing state-of-the-art methods.