Relationship between fasting prior to contrast-enhanced CT and adverse reaction in patients with allergies history

AIM

To examine the relationship between fasting prior to contrast-enhanced CT (CECT) and adverse reaction (AR) in patients with allergies history.

MATERIALS AND METHODS

Patients with allergies history who underwent CECT from January 2014 to December 2020 (713 cases with iodinated contrast media (ICM)-related allergy history and 27045 cases with unrelated allergies history) were retrospectively analyzed. The occurrence of ICM-related AR and patient information were recorded. The relationship between fasting and AR and emetic complications was analyzed.

RESULTS

There was no statistical difference in the overall incidence of AR and emetic complications between fasting group and non-fasting group (P>0.05) and fasting was not an influence factor for overall AR occurrence in patients with both ICM-related and unrelated allergies history. However, the incidence of severe AR in fasting group was higher than that in non-fasting group (P=0.01) in patients with unrelated allergies history. The AR incidence in fasting group was higher than that in non-fasting group (P=0.022) when receiving abdominal examinations in patients with unrelated allergies history. There was no statistical difference in the incidence of AR with different occurrence time between fasting group and non-fasting group (P>0.05) in patients with both ICM-related and unrelated allergies history.

CONCLUSIONS

Fasting was associated with higher incidence of severe AR and was associated with higher AR incidence when receiving abdominal examinations in patients with unrelated allergies history. Fasting did not have effects on the occurrence time of AR in patients with allergies history. These provided new guidance for usage of ICM in patients with allergies history.

A comprehensive analysis of LINC00958 as a prognostic biomarker for head and neck squamous cell carcinoma

This work focused on exploring whether the long intergenic non-protein coding RNA LINC00958 is associated with the prognosis of head and neck squamous cell carcinoma (HNSCC). Associations of the LINC00958 expression level with clinicopathological features of HNSCC were investigated by logistic regression and Wilcoxon signed-rank test. The Kaplan-Meier method was applied to evaluate patient survival. Clinical data and expression profiles were obtained from The Cancer Genome Atlas (TCGA). Associations of patient clinical characteristics with overall survival (OS), progression-free interval (PFI), and disease-specific survival (DSS) were assessed by univariate and multivariate analysis using the Cox proportional hazard model. Immune cell infiltration analysis and gene set enrichment analysis (GSEA) were applied to determine any significant effects of LINC00958. High LINC00958 expression was related to early pT stage (P < 0.01), primary therapy outcome (P < 0.01), HPV status (P < 0.001), lymphovascular invasion (P < 0.001), and perineural invasion (P < 0.01). The receiver operating characteristic curve showed strong prognostic power for LINC00958 (area under curve = 0.886). High LINC00958 expression predicted poor OS (P = 0.007), DSS (P = 0.036), and PFI (P = 0.040). LINC00958 was related to signalling pathways and the infiltration of certain immune cells. miR-27b-5p was significantly associated with LINC00958, and downstream NT5E predicted poor survival in HNSCC cases. LINC00958 may affect the prognosis by regulating NT5E via miR-27b-5p, and could serve as a possible factor to predict the prognosis of HNSCC, especially oral squamous cell carcinoma.

[Zinc finger protein-36 deficiency inhibits osteogenic differentiation of mouse bone marrow-derived mesenchymal stem cells and preosteoblasts by activating the ERK/MAPK pathway]

OBJECTIVE

To explore the role of zinc finger protein 36(ZFP36) in regulating osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and preosteoblasts.

METHODS

ZFP36 expression was observed in primary mouse BMSCs and mouse preosteoblasts (MC3T3-E1 cells) during induced osteogenic differentiation. Zfp36-deficient cell models were constructed in the two cells using RNA interference technique and the changes in differentiation capacities of the transfected cells into osteoblasts were observed. Transcriptome sequencing was used to investigate the potential mechanisms of ZFP36 for regulating osteoblast differentiation of the two cells. U0126, a ERK/MAPK signal suppressor, was used to verify the regulatory mechanism of Zfp36 in osteogenic differentiation of Zfp36-deficient cells.

RESULTS

During the 14-day induction of osteogenic differentiation, both mouse BMSCs and MC3T3-E1 cells exhibited increased expression of ZFP36, and its mRNA expression reached the peak level on Day 7(P < 0.0001). The Zfp36-deficient cell models showed reduced intensity of alkaline phosphatase (ALP) staining and alizarin red staining with significantly lowered expressions of the osteogenic marker genes including Alpl, Sp7, Bglap and Ibsp (P < 0.01). Transcriptome sequencing verified the reduction of bone mineralization-related gene expressions in Zfp36-deficient cells and indicated the involvement of ERK signaling in the potential regulatory mechanism of Zfp36. Immunoblotting showed that pERK protein expression increased significantly in Zfp36-deficient cells compared with the control cells. In Zfp36-deficient MC3T3-E1 cells, inhibition of activated ERK/MAPK signaling with U0126 resulted in obviously enhanced ALP staining and significantly increased expressions of osteoblast differentiation markers Runx2 and Bglap (P < 0.05).

CONCLUSIONS

ZFP36 is involved in the regulation of osteoblast differentiation of mouse BMSCs and preosteoblasts, and ZFP36 deficiency causes inhibition of osteoblast differentiation of the cells by activating the ERK/MAPK signaling pathway.

Characterization of novel polysulfide polymer coated fly ash and its application in mitigating diffusion of contaminants

Fly ash consists of a considerable amount of hazardous elements with high mobility, posing substantial environmental risks during storage in surface impoundments and landfills. This hinders its efficient reuse in construction or material industries. To enhance the versatility of fly ash applications, a novel surface modification technique, termed SuMo, has been developed to create a hydrophobic polysulfide polymer coating on the surface of fly ash particles. The physicochemical properties of SuMo fly ash samples were examined using atomic force microscopy (AFM), environmental scanning electron microscopy (ESEM), thermal gravimetric analysis (TGA), Fourier Transform Infrared spectroscopy (FTIR), and leaching of hazardous elements was tested under practical environmental conditions (pH 4-12) based on the EPA's leaching environmental assessment framework (LEAF). The successful coating of polysulfide polymer on fly ash surface was verified through an increased percentage of C, S, and O in elemental mapping, coupled with the identification of S-O, CO, and C-H functional groups consistent with the chemical structure of polysulfide polymer. While the SuMo fly ash particles maintained their spherical shape, they exhibited increased surface roughness, robust hydrophobicity, and thermal stability up to 250 °C. Notably, owing to the coating's resilience against water leaching, the SuMo fly ash demonstrated a substantial reduction (up to 60-fold) in leachate concentrations of multiple concerning elements, including B, Be, Ba, Mn, Zn, As, Cr, Hg, etc., under various pH conditions compared to the uncoated fly ash. Furthermore, the polysulphide polymer coating effectively prevented Hg volatilization from fly ash below 163 °C. This study highlights the efficacy of the developed polysulfide polymer coating in mitigating the diffusion of hazardous elements from fly ash, thereby enhancing its potential reutilization in material, construction, and agriculture industries.

Niobium-Based Oxide for Anode Materials for Lithium-Ion Batteries

Recently, it has become imperative to develop high energy density as well as high safety lithium-ion batteries (LIBS) to meet the growing energy demand. Among the anode materials used in LIBs, the currently used commercial graphite has low capacity and is a safety hazard due to the formation of lithium dendrites during the reaction. Among the transition metal oxide (TMO) anode materials, TMO based on the intercalation reaction mechanism has a more stable structure and is less prone to volume expansion than TMO based on the conversion reaction mechanism, especially the niobium-based oxide in it has attracted much attention. Niobium-based oxides have a high operating potential to inhibit the formation of lithium dendrites and lithium deposits to ensure safety, and have stable and fast lithium ion transport channels with excellent multiplicative performance. This review summarizes the recent developments of niobium-based oxides as anode materials for lithium-ion batteries, discusses the special structure and electrochemical reaction mechanism of the materials, the synthesis methods and morphology of nanostructures, deficiencies and improvement strategies, and looks into the future developments and challenges of niobium-based oxide anode materials.

Campothecin suppresses cell proliferation and migration in head and neck squamous cell carcinoma by blocking RAB27A-mediated phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) pathway

Camptothecin (CPT), a naturally occurring alkaloid derived from the Camptotheca acuminate plant, exerts anti-tumor properties. However, its specific impact on head and neck squamous cell carcinoma (HNSCC) remains uncertain. The study was to explore the action and mechanism of CPT on HNSCC cells. First, two HNSCC cell lines (FaDu and TU686) and a normal immortalized keratinocyte (HEK001) cell line, were exposed to a spectrum of CPT concentrations (ranging from 10 to 50 μM) for durations of 24 h and 48 h. Cell viability, proliferation, migration, and invasion were assessed by CCK-8 assay, EdU incorporation assay, wound healing assay and transwell assay. Subsequently, si-RAB27A or negative control (NC) was introduced into FaDu and TU686 cells through transfection, and the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway was manipulated with L740Y-P, an activator of this pathway. The expression of proliferating cell nuclear antigen (PCNA), E-cadherin, PI3K/AKT signaling factors and RAB27A were determined by Western blot analysis. RAB27A was detected by immunofluorescence assay. It was found that CPT significantly hindered the viability, proliferation (p<0.01), migration (p<0.001), and invasion (p<0.001) of FaDu and TU686 cells. At the molecular level, administration of CPT caused a decline in the expression of PCNA, P-PI3K, P-AKT, and RAB27A, alongside an elevation in E-cadherin levels within HNSCC cells (p<0.05, p<0.01 and p<0.001). Reducing RAB27A expression enhanced the suppressive impacts of CPT on HNSCC cell viability (p<0.05 and p<0.01), migration (p<0.001) and invasion (p<0.01), these effects that were reversed upon treatment with L740Y-P in HNSCC cells (p<0.001). In summary, our study highlights the efficacy of CPT in HNSCC, demonstrating its influence on cell processes via the RAB27A-mediated PI3K/AKT pathway.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Investigating the Effect of an Anti-Inflammatory Drug in Determining NURR1 Expression and Thus Exploring the Progression of Parkinson's Disease

Nonsteroidal anti-inflammatory drugs are the most widely used drugs for Parkinson's disease (PD), of which ibuprofen shows positive effects in suppressing symptoms; however, the associated risk needs to be addressed in different pathological stages. Initially, we developed an initial and advanced stage of the Parkinson disease mouse model by intraperitoneal injection of MPTP (20 mg/kg; 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine) for 10 and 20 days, respectively. Subsequently, ibuprofen treatment was administered for 2 months, and a pole test, rotarod test, histology, immunohistochemistry, and western blotting were performed to determine neuronal motor function. Histological analysis for 10 days after mice were injected with MPTP showed the onset of neurodegeneration and cell aggregation, indicating the initial stages of Parkinson's disease. Advanced Parkinson's disease was marked by Lewy body formation after another 10 days of MPTP injection. Neurodegeneration reverted after ibuprofen therapy in initial Parkinson's disease but not in advanced Parkinson's disease. The pole and rotarod tests confirmed that motor activity in the initial Parkinson disease with ibuprofen treatment recovered (p<0.01). However, no improvement was observed in the ibuprofen-treated mice with advanced disease mice. Interestingly, ibuprofen treatment resulted in a significant improvement (p<0.01) in NURR1 (Nuclear receptor-related 1) expression in mice with early PD, but no substantial improvement was observed in its expression in mice with advanced PD. Our findings indicate that NURR1 exerts anti-inflammatory and neuroprotective effects. Overall, NURR1 contributed to the effects of ibuprofen on PD at different pathological stages.

[Cost-effectiveness of HCV testing strategies for hepatitis C elimination in general population in China]

Objective: To evaluate the cost-effectiveness of hepatitis C screening in general population in China, and find the age group in which hepatitis C screening can achieve the best cost-effectiveness. Methods: A decision-Markov model was constructed by using software TreeAge pro 2019 to simulate the outcomes of hepatitis C disease pregression of 100 000 persons aged 20-59 years. The cost-effectiveness of the strategies were evaluated from societal perspectives by using incremental cost-effectiveness ratio (ICER) and net monetary benefit (NMB). One-way sensitivity analysis and probability sensitivity analysis were used to evaluate the uncertainty of parameters and model. Results: Hepatitis C screening was cost-effective in people aged 20- 59 years and the cost effectiveness was best in age group 40-49 years. Compared with non-screening strategy of hepatitis C in people aged 20-59 years, the incremental cost was 161.24 yuan, the incremental utility was 0.003 6 quality adjusted life years (QALYs)/per person, ICER was 45 197.26 yuan/QALY, ICER was less than the willing payment threshold. The ICER and NMB in all age groups were 42 055.06-53 249.43 yuan/QALY and 96.52-169.86 yuan/per person. Hepatitis C screening in people aged 40-49 years had the best cost-effectiveness. The results of one-way sensitivity analysis showed that the discount rate, anti-HCV detection cost, anti-HCV infection rate and the cost of direct antiviral agents were the main factors influencing economic evaluation. The results of the probability sensitivity analysis indicated that the model analysis was stable. Conclusions: Implementing hepatitis C screening based on medical institutions is cost-effective in people aged 20- 59 years, especially in those aged 40-49 years. Implementing the HCV screening strategy of be willing to test as far as possible in general population can reduce hepatitis C disease burden in China.

[Comparison among different flushing media for intracoronary imaging with optical coherence tomography]

Objective: To explore the effects and safety of saline mixed 1∶1 with contrast medium (mixed medium) and pure heparinized saline as alternative media for optimal Optical Coherence Tomography (OCT) guided percutaneous coronary intervention (PCI). Methods: This single-center, prospective cohort study enrolled patients who underwent PCI with OCT guidance for chronic stable angina or acute coronary syndrome at the Department of Cardiology, the Second Hospital of Jilin University from October 2021 to August 2022. The target vessels were examined using OCT with three different flushing media at the same anatomical positions: contrast agent, mixed medium, and pure heparinized saline. An independent observer analyzed all imaging results and evaluated the lumen imaging quality, using the proportion of the clear imaging field (CIF%) as a quantitative measure for analysis. The average luminal diameter was compared among different flushing media. The study also assessed the image quality of the luminal anatomical structures, lesion pathologies, and stents. Results: A total of 105 patients were enrolled in the study, including 110 target vessels. The age of the enrolled patients was (60.5±8.4) years, with 60 male patients (57.1%). OCT examinations were successfully completed using all three media, and no related complications were observed in any groups. The three flushing media presented with the same image quality in terms of depicting the lumen anatomical structures, lesion characteristics, and stent-related features. The mixed medium group achieved a comparable CIF% to the contrast group with both right and left coronary arteries (right coronary 100.0% (100.0%, 100.0%) vs. 100.0% (100.0%, 100.0%), P>0.05; left coronary 100.0% (95.9%, 100.0%) vs. 100.0% (100.0%, 100.0%), P>0.05). While the saline group reached a comparable CIF% to the contrast group with right coronary arteries (100.0% (97.6%, 100.0%) vs. 100.0% (95.9%, 100.0%), P>0.05) but showed a significantly lower CIF% with left coronary arteries (84.9% (75.9%, 93.4%) vs. 100.0% (100.0%, 100.0%), P<0.05). For the average diameter of the coronary lumen, there was no statistically significant difference between the mixed medium group and the saline group compared to the contrast group with both right and left coronary arteries (P>0.05). Conclusions: A 1∶1 heparinized saline and contrast mixture can serve as a substitute flushing medium for OCT examination during PCI procedure. Pure saline can also yield good results in OCT examination of the right coronary artery, and both alternatives are safe for use as flushing medium in OCT imaging.

[Quantitative analysis of risk assessment indicators for re-introduction of imported malaria in China]

OBJECTIVE

To quantitatively analyze the risk indicators of re-introduction of imported malaria in China and their weighting coefficients, so as to investigate the difference in the contribution of risk indicators included in the current risk assessment framework for re-introduction of imported malaria in China to the risk assessment of re-introduction of imported malaria.

METHODS

Publications pertaining to the risk assessment framework for re-introduction of imported malaria in China that reported the risk indicators and their weighting coefficients were retrieved in PubMed, Web of Science, CNKI, Wanfang Data, and VIP with terms of "malaria", "re-introduction/re-transmission/re-establishment", "risk assessment/risk evaluation/risk prediction" from the inception of the database through 3 August 2023, and literature search was performed in Google Scholar to ensure the comprehensiveness of the retrieval. Basic characteristics of included studies were extracted using pre-designed information extraction forms by two investigators, and data pertaining to risk indicators of re-introduction of imported malaria were cross-checked by these two investigators. The risk indicators included in the risk assessment framework for re-introduction of imported malaria in China and their weighting coefficients were visualized with the Nightingale's rose diagrams using the software R 4.2.1, and the importance of risk indictors was evaluated with the frequency of risk indicators included in the risk assessment framework and the ranking of weighting coefficients of risk indicators. In addition, the capability of risk indicators screened by different weighting methods was compared by calculating the ratio of the maximum to the minimum of the weighting coefficients of the risk indicators screened by different weighting methods.

RESULTS

A total of 2 138 publications were retrieved, and following removal of duplications and screening, a total of 8 publications were included in the final analysis. In these 8 studies, 8 risk assessment frameworks for re-introduction of imported malaria in China and 52 risk indicators of re-introduction of imported malaria were reported, in which number of imported malaria cases (n = 8) and species of malaria vectors were more frequently included in the risk assessment frameworks (n = 8), followed by species of imported malaria parasites (n = 6) and population density of local malaria vectors (n = 6), and species of local malaria vectors (n = 6), number of imported malaria cases (n = 5) and species of imported malaria parasites had the three highest weighting coefficients (n = 4). The weighting methods included expert scoring method, combination of expert scoring method and analytic hierarchy process, and combination of expert scoring method and entropy weight method in these 8 studies, and the ratios of the maximum to the minimum of the weighting coefficients of the risk indicators screened by the expert scoring method were 1.143 to 2.241, while the ratios of the maximum to the minimum of the weighting coefficients of the risk indicators screened by combination of the expert scoring method and analytic hierarchy process were 34.970 to 162.000.

CONCLUSIONS

Number of imported malaria cases, species of imported malaria parasites, species of local malaria vectors and population density of local malaria vectors are core indicators in the current risk assessment framework for re-introduction of imported malaria in China. Combination of the expert scoring method and analytic hierarchy process is superior to the expert scoring method alone for weighting the risk indicators.

[The ventilation efficacy and safety of new nasopharyngeal airway applied in left atrial appendage occlusion]

Objective: The present retrospective study aimed to analyses the ventilation efficacy and safety of new nasopharyngeal airway applied in left atrial appendage occlusion. Methods: A total of 37 advanced aged patients diagnosed with atrial fibrillation(>65 years)who underwent left atrial appendage occlusion (LAAO) in Xuanwu Hospital of Capital Medical University from March 2021 to March 2022 were enrolled in this study. All patients received supplemental oxygen by a new nasopharyngeal airway to ensure intraoperative ventilation. The primary outcome was the occurrence of hypoxemia. The secondary outcomes included the incidence of hypotension after anesthesia, the incidence of body movement during surgery, significant fluctuations of the vital signs such as mean arterial pressure (MAP), heart rate (HR), saturation of pulse oxygen (SpO2) and respiratory rate (RR) at different time points (T1: pre-operation; T2: at the time of placing nasopharyngeal airway; T3: at the time of placing transesophageal echocardiography(TEE); T4: at the time of TEE intraoperative exploration; T5: end of the surgery; T6: at the time of patient woke up), and the incidence of postoperative adverse events. Results: There were 24 males and 13 females with a mean age of (73.8±7.7) years. The incidence of hypoxemia was 16.2% (6/37), which could return to normal after simple treatment. The incidence of hypotension was 27.0% (10/37), occurred after anesthesia induction mainly.32.4% (12/37) of the patients experienced movements, but no adverse events led to surgical termination. MAP at different time points was significantly different (P=0.001), but other vital signs of HR, SpO2 and RR were not significantly different(all P>0.05), without serious hemodynamic fluctuations. The incidence of postoperative adverse cardiovascular events was 10.8% (4/37), and delirium was 2.7% (1/37). All patients successfully completed the surgery and were safely discharged from the hospital. Conclusion: The new nasopharyngeal airway can meet the requirements of airway management during left atrial appendage occlusion under intravenous anesthesia without serious adverse events.

[SRF-rearranged cellular perivascular myoid tumor: a clinicopathological analysis of two cases]

Objective: To investigate the clinicopathological features, immunophenotype, diagnosis and differential diagnosis of SRF-rearranged cellular perivascular myoid tumor. Methods: Two cases of SRF-rearranged cellular perivascular myoid tumor diagnosed in the Department of Pathology, Fudan University Shanghai Cancer Center from October 2021 to March 2022 were collected. Immunohistochemical staining, fluorescence in-situ hybridization (FISH) and next-generation sequencing (NGS) were performed, and the literature was reviewed. Results: Case 1, a 3-month-old boy presented with a painless tumor of the scalp, measuring about 2 cm in diameter. Case 2, a 3-year-old girl complained with a painless tumor of the knee, measuring approximately 1.5 cm in diameter. Microscopically, the tumor had a clear boundary and showed multinodular growth. The tumor was mainly composed of spindle cells arranged in long intersecting fascicles associated with thin, slit-like or branching ectatic vessels, focally forming hemangiopericytoma-like appearance. The tumor cells were abundant, but there was no obvious atypia. Mitotic figures (3-4/10 HPF) were noted. H-caldesmon and SMA were positive in both cases. Case 1 showed diffuse and strong positivity for Desmin, and focally for CKpan. Ki-67 proliferation index was 20% and 30%, respectively. FISH displayed NCOA2 gene translocation in case 1 and the RELA gene translocation in case 2. NGS detected the SRF-NCOA2 gene fusion in case 1 and the SRF-RELA gene fusion in case 2. Both patients underwent local excisions. During the follow-up of 5-14 months, case 1 had no local recurrence, while case 2 developed local recurrence 1 year post operatively. Conclusions: SRF-rearranged cellular perivascular myoid tumor is a novel variant of perivascular cell tumor, which tends to occur in children and adolescents. The tumor forms a broad morphologic spectrum ranging from a pericytic pattern to a myoid pattern, and include hybrid tumors with a mixture of pericytic and myoid patterns. Due to its diffuse hypercellularity and increased mitotic figures and smooth muscle-like immunophenotype, the tumor is easy to be misdiagnosed as myogenic sarcomas. The tumor usually pursues a benign clinical course and rare cases may locally recur.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Belimumab therapy for refractory immune thrombocytopenia in systemic lupus erythematosus patients with anti-phospholipid antibodies

OBJECTIVE

To observe the effect of belimumab treatment in refractory anti-phospholipid antibody-associated immune thrombocytopenia with systemic lupus erythematosus (SLE).

METHOD

Four SLE patients with refractory anti-phospholipid antibody-associated immune thrombocytopenia were included in this one-arm observational study. Inclusion criteria were a diagnosis of SLE according to 1997 American College of Rheumatology criteria, severe immune thrombocytopenia (platelets <30 × 109/L), no bleeding symptoms, lack of satisfactory response to traditional treatment, and high-titre anti-phospholipid antibodies. All patients received belimumab (Benlysta®) for 6 months.

RESULTS

The mean platelet count was 21.8 × 109 cells/L, ranging between 16 and 29 × 109/L at baseline, 123.3 × 109/L at 1 month, and 172.5 × 109/L at the end of 6 months after belimumab treatment. No bleeding complications occurred during the entire follow-up period.

CONCLUSION

In this study, belimumab reduced the anti-phospholipid antibodies while increasing the platelet count in SLE patients with anti-phospholipid antibody-associated immune thrombocytopenia.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

[Application value of questionnaires in the screening obstructive sleep apnea syndrome in pregnancy across trimesters]

Objective: To evaluate the clinical utility value of questionnaires of Berlin, STOP, STOP-Bang (SBQ), Epworth Sleepiness Scale (ESS) in screening obstructive sleep apnea syndrome (OSAS) in pregnant women of different trimesters. Methods: Consecutive pregnant women at high risk for OSAS were enrolled from January, 2021 to April, 2022 at the obstetric clinic of Peking University People's Hospital. They completed questionnaires of Berlin, STOP, SBQ, ESS and also underwent an overnight polysomnography (PSG). To evaluate the accuracy of questionnaires of Berlin, STOP, SBQ, ESS, sensitivity, specificity, positive predictive values, negative predictive values and the area under the receiver operating characteristics (ROC) curve of these questionnaires in pregnancy across trimesters (Pregnancy 1-15 weeks was the first stage, pregnancy 16-27 weeks was the second stage, and pregnancy 28-40 weeks was the third stage) were calculated. Results: A total of 100 pregnant women [(34.5±4.3) years old (26-46 years old)] were included in this study, including 20, 35 and 45 pregnant women in the first, second and third trimester of pregnancy, respectively. Based on PSG results, 45 (45%) of 100 pregnant women were diagnosed with OSAS. The overall predictive values of the four questionnaires were not good, area under[AUC(95%CI)] the ROC curve ESS, Berlin questionnaire STOP and SBQ were 0.54(0.43, 0.66), 0.59 (0.47, 0.70), 0.62(0.51, 0.73) and 0.61 (0.49, 0.72), respectively, sensitivity was 35.6%, 65.9%, 48.9%, 28.9%, specificity was 71.7%, 52.5%, 73.6%, 92.5%. When categorized according to trimesters, the predicted values of the four questionnaires increased in the first trimester, the AUC (95%CI) of STOP questionnaire was 0.81 (0.61, 1.00), sensitivity was 75.0%, specificity was 87.5%. Conclusion: The overall predictive power of the four screening questionnaires is limited in pregnant women. But predictive value of STOP questionnaire is acceptable in the first trimester.

[Nomogram prediction model of cervical anastomotic leakage after esophageal cancer surgery]

Objective: To retrospectively analyze the risk factors of anastomotic leakage in the neck after esophageal cancer and establish a nomogram prediction model that can accurately predict the occurrence of anastomotic leakage in the neck of the patient. Methods: The study retrospectively analyzed 702 patients who underwent radical esophageal cancer surgery between January 2010 and May 2015 at Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. A multivariate logistic regression model was used to determine the risk factors for neck anastomotic leak, and a nomogram model was constructed, internal validation methods were used to evaluate and verify the predictive effectiveness of the nomogram. Results: There were 702 patients in the whole group, 492 in the training group and 210 in the validation group. The incidence of postoperative cervical anastomotic leak was 16.1% (79/492) in 492 patients with esophageal cancer in the training group. Multifactorial analysis revealed calcification of the descending aorta (OR=2.12, 95% CI: 1.14, 3.94, P=0.018), calcification of the celiac artery (OR=2.29, 95% CI: 1.13, 4.64, P=0.022), peripheral vascular disease (OR=5.50, 95% CI: 1.64, 18.40, P=0.006), postoperative ventilator-assisted breathing (OR=5.33, 95% CI: 1.83, 15.56, P=0.002), pleural effusion or septic chest (OR=3.08, 95% CI: 1.11, 8.55, P=0.031), incisional fat liquefaction and infection (OR=3.49, 95% CI: 1.68, 7.27, P=0.001) were independent risk factors for the development of cervical anastomotic leak after esophageal cancer surgery. The results of the nomogram prediction model showed that the consistency indices of the training and external validation groups were 0.73 and 0.74, respectively (P<0.001), suggesting that the prediction model has good predictive efficacy. Conclusion: The nomogram prediction model can intuitively predict the incidence of postoperative cervical anastomotic leakage in patients with high prediction accuracy, which can help provide a clinical basis for preventing cervical anastomotic leak and individualized treatment of patients.

Estrogen as a guardian of auditory health: Tsp1-CD47 axis regulation and noise-induced hearing loss

OBJECTIVES

This study aimed to analyze the role of estrogen in noise-induced hearing loss (NIHL) and uncover underlying mechanisms.

METHODS

An ovariectomized Sprague-Dawley rat model (OVX) was constructed to investigate the hearing threshold and auditory latency before and after noise exposure using the auditory brainstem response (ABR) test. The morphological changes were assessed using immunofluorescence, scanning electron microscopy and transmission electron microscopy. Proteomics and bioinformatics were used to analyze the mechanism. The findings were further verified through western blot and Luminex liquid suspension chip technology.

RESULTS

After noise exposure, OVX rats exhibited substantially elevated hearing thresholds. A conspicuous delay in ABR wave I latency was observed, alongside increased loss of outer hair cells, severe collapse of stereocilia and pronounced deformation of the epidermal plate. Accordingly, OVX rats with estrogen supplementation exhibited tolerance to NIHL. Additionally, a remarkable upregulation of the thrombospondin 1 (Tsp1)-CD47 axis in OVX rats was discovered and verified.

CONCLUSIONS

OVX rats were more susceptible to NIHL, and the protective effect of estrogen was achieved through regulation of the Tsp1-CD47 axis. This study presents a novel mechanism through which estrogen regulates NIHL and offers a potential intervention strategy for the clinical treatment of NIHL.

[Migratory pulmonary ground glass opacities caused by SARS-CoV-2 infection in a patient on B-cell depletion therapy]

In immunosuppressed individuals, the manifestation of viral pneumonia due to SARS-CoV-2 infection differs from that in healthy individuals. We reported a unique case of a 58-year-old male patient with B-cell depletion following treatment with the anti-CD20 monoclonal antibody. He presented to the Department of Pulmonary and Critical Care Medicine with complaints of intermittent fever and cough for three months, aggravated by shortness of breath for one month. He was previously diagnosed with stage IVA follicular lymphoma in April 2022 and underwent chemotherapy with Obinutuzumab (anti-CD20 monoclonal antibody). His last treatment was on November 3, 2022. On December 20, 2022, after contact with a SARS-CoV-2-infected person, he exhibited symptoms of fever peaking at 39.0 ℃, cough, and sputum production. A positive SARS-CoV-2 nucleic acid result was confirmed from a pharyngeal swab. Nine days later (December 29, 2022), the patient still had a fever. Chest CT showed multiple small pieces of ground glass opacities (GGOs) in both lower lungs. The diagnosis of viral pneumonia due to SARS-CoV-2 infection was confirmed. After five days of treatment with nirmatrelvir/ritonavir (Paxlovid) and intravenous dexamethasone (5 mg/d), his fever subsided. However, a subsequent chest CT on January 9, 2023 showed partial resorption of multiple GGOs in both lungs, accompanied by novel focal lesions. The patient developed a fever again on January 29, 2023, after which he had recurrent symptoms of fever, cough, and sputum, with intermittent short courses of antibiotics and dexamethasone, which never completely resolved. Multiple chest CTs during this period showed recurrent GGOs and consolidations in both lungs, demonstrating a migratory pattern. The patient was admitted to our hospital on March 7, 2023, with a peripheral blood test suggesting lymphocytopenia, a CD19+B lymphocyte count of zero, and negative IgG and IgM for SARS-CoV-2. A bronchoscopy and bronchoalveolar lavage fluid (BALF) analysis indicated a significantly elevated lymphocyte percentage and the presence of SARS-CoV-2 nucleic acid. Given the three-month history of chronic fever and respiratory symptoms, changing bilateral pulmonary infiltrates, and lack of SARS-CoV-2 humoral immunity, a diagnosis of persistent SARS-CoV-2 infection was considered. Subsequent treatment with Paxlovid for 15 days resulted in the resolution of all symptoms. A follow-up chest CT one month later showed almost complete normalization.

Investigations of clinical characteristics and inflammatory markers of febrile seizures induced by coronavirus infection

The study of children who experienced with febrile seizures(FS) as a result of COVID-19 infection to gain insight into the clinical characteristics and prognosis of neurological damage, with the aim of improving prevention, diagnosis, and the treatment of neurological complications. This study investigated the clinical features of 53 children with FS who were admitted to Sanya Women and Children's Hospital from December 1, 2022, to January 31, 2023. The results indicated that the duration of convulsion in the case and control group was 7.90±8.91 and 2.67±1.23 (minutes) respectively. The analysis reveals that convulsions occurred within 24 hours in 39 cases (95.12%) of the case group, and in 8 cases (66.7%) of the control group. The difference was statistically significant (P<0.05). Additionally, the case group presented lower counts of WBC and NEU compared to the control group (p<0.05). The findings indicate that convulsions manifest at earlier stages of COVID-19 in children and the last longer than in the control group. It is therefore crucial for healthcare workers to remain attentive to patients with COVID-19 who report fever within 24 hours, and act promptly to implement preventive measures, particularly in cases of prolonged fever. It is essential to integrate the clinical manifestation, particularly convulsions, and the continuous numerical changes of inflammatory factors to assess COVID-19 linked with febrile seizures. In addition, larger-scale multi-center and systematic research are necessary to aid clinicians in monitoring neuropathological signals and biological targets, enabling more equitable diagnosis and treatment plans.

The impact of instant neutrophil gelatinase-associated lipocalin level on the severity of septic acute kidney injury

OBJECTIVE

The clinical value of increased levels of neutrophil gelatinase-associated lipocalin (NGAL) in patients with septic acute kidney injury (AKI) is still unclear. This study aimed to assess the link between illness severity and NGAL in patients with septic AKI.

PATIENTS AND METHODS

This is a retrospective observational study that took place at the Fourth Hospital of Hebei Medical University, Shijiazhuang, China. The cohort included 365 patients who were admitted to the ICU during the 21-month period. Of them, 18 patients were diagnosed with sepsis (septic group). The average age of patients in the septic group was over 65, and 60.00% of them eventually progressed to septic AKI. Plasma NGAL (pNGAL) and urine NGAL (uNGAL) levels at defined time points were measured. AKI staging was done based on the Kidney Disease Improving Global Outcomes (KDIGO) classification. The Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were determined. Patterns and associations between NGAL levels with SOFA scores and different stages of septic AKI were investigated.

RESULTS

Both pNGAL and uNGAL showed a positive correlation with SOFA and proved to be reliable predictors of the same. Furthermore, the accuracy of severe sepsis (SOFA ≥ 8) was 0.67 for pNGAL and 0.66 for uNGAL. Real-time detection of pNGAL and uNGAL indicated that they were good biomarkers of severe septic AKI. Area under the receiver operating characteristic (AUROC) for pNGAL and uNGAL were 0.72 (0.69-0.85), and 0.83 (0.71-0.95), respectively. However, only patients with KDIGO 3 AKI presented significantly elevated levels of pNGAL (p < 0.05). Furthermore, the uNGAL level at each stage of septic AKI was higher than that of the non-AKI period (p < 0.01).

CONCLUSIONS

In patients with septic AKI, levels of NGAL correlated with SOFA. Levels of pNGAL were good predictors of severe kidney injury and uNGAL levels could detect mild stages of AKI.

Electroacupuncture Stimulation Alleviates Inflammatory Pain in Male Rats by Suppressing Oxidative Stress

In the present study, we focused on whether the analgesic effect of Electroacupuncture (EA) is related to the regulation of oxidative stress. We established a chronic inflammatory pain model in male rats by a single injection of complete Freund's adjuvant (CFA) and then treated the animals with daily EA stimulation at the site of "zusanli". The analgesic effect of EA was evaluated by measuring the paw withdrawal threshold (PWT) when rats received mechanical and thermal pain stimulation. The levels of inflammation-related molecules and oxidative stress-related markers in the spinal cord were measured by western blotting or ELISA kits. EA stimulation and antioxidants effectively increased the PWT in CFA rats. Co-treatment of CFA rats with the ROS donor t-butyl hydroperoxide (t-BOOH) further decreased the PWT and weakened the analgesic effect of EA. EA treatment inhibited inflammation and oxidative stress, as shown by decreased levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and MDA and increased activity of SOD and catalase. Moreover, EA reduced the expression of p-p38, p-ERK, and p-p65 and simultaneously downregulated the expression of TRPV1 and TRPV4 in CFA rats. In an in vitro study, direct stimulation with t-BOOH to the C6 cells increased the production of TNF-alpha, IL-1beta, IL-6, activated p38, ERK, and p65 and up-regulated the expression of TRPV1 and TRPV4, and these effects could be prevented by the ROS scavenger PBN. Taken together, our data indicate that the inhibition of oxidative stress and the generation of ROS contribute to the analgesic effect of EA in male CFA rats.

[Preliminary application of recombinase -aided amplification in detection of Clonorchis sinensis metacercariae in freshwater fish]

OBJECTIVE

To evaluate the performance of recombinase-aided amplification (RAA) assay in detection of Clonorchis sinensis metacercariae in freshwater fish samples, so as to provide insights into standardization and field application of this assay.

METHODS

Wild freshwater fish samples were collected in the rivers of administrative villages where C. sinensis-infected residents lived in Jiangyan District, Xinghua County and Taixing County of Taizhou City, Jiangsu Province from June to September 2022. Genomic DNA was extracted from six freshwater fish specimens (5 g each) containing 0, 1, 2, 4, 8 and 16 C. sinensis metacercariae for fluorescent RAA assay, and the diagnostic sensitivity was evaluated. Fluorescent RAA assay was performed with genomic DNA from C. sinensis, Metorchis orientalis, Haplorchis pumilio and Centrocestus formosanus metacercariae as templates to evaluate its cross-reactions. In addition, the detection of fluorescent RAA assay and direct compression method for C. sinensis metacercariae was compared in field-collected freshwater fish samples.

RESULTS

Positive amplification was found in fresh-water fish specimens containing different numbers of C. sinensis metacercariae, and fluorescent RAA assay was effective to detect one C. sinensis metacercaria in 5 g freshwater fish specimens within 20 min. Fluorescent RAA assay tested negative for DNA from M. orientalis, H. pumilio and C. formosanus metacercariae. Fluorescent RAA assay and direct compression method showed 5.36% (93/1 735) and 2.88% (50/1 735) detection rates for C. sinensis metacercariae in 1 735 field-collected freshwater fish samples, with a statistically significant difference seen (χ2 = 478.150, P < 0.001). There was a significant difference in the detection of C. sinensis metacercariae in different species of freshwater fish by both the direct compression method (χ2 = 11.20, P < 0.05) and fluorescent RAA assay (χ2 = 20.26, P < 0.001), and the detection of C. sinensis metacercariae was higher in Pseudorasbora parva than in other fish species by both the direct compression method and fluorescent RAA assay (both P values < 0.05).

CONCLUSIONS

Fluorescent RAA assay has a high sensitivity for detection of C. sinensis metacercariae in freshwater fish samples, and has no cross-reactions with M. orientalis, H. pumilio or C. formosanus metacercariae. Fluorescent RAA assay shows a higher accuracy for detection of C. sinensis infections in field-collected freshwater fish than the direct compression method.

Quantum dot heterostructures on N-doped graphene with accelerated diffusion kinetics for stable lithium-ion storage

The high energy density and low self-discharge rate of lithium-ion batteries make them promising for large-scale energy storage. However, the practical development of such electrochemical energy storage systems relies heavily on the development of anode materials with high multiplier capacity and stable cycle life. Here, a simple and efficient one-step hydrothermal method is used to obtain stannide heterostructures, which are loaded on N-doped graphene (SnS2/SnO2@NG) that promotes Li+ diffusion for fast charge transfer. It is demonstrated that the built-in electric field generated by the electron transfer from electron-rich SnS2 to SnO2 in the stannide heterojunction collectively provides abundant cation adsorption sites, accelerating the migration of Li+ thus improving the electrochemical reaction kinetics. Besides, the SnS2/SnO2 nanoparticles have high structural stability, and the heterojunction compressive stresses obtained from density functional theory (DFT) calculations can significantly limit the structural damage. When applied as anodes in Li+ batteries with 300 cycles at 0.5 A/g, we achieved a high reversible capacity of 892.73 mAh/g. The rational design of low-cost batteries for energy storage and conversion can benefit from the quantitative design of fast and persistent charge transfer in a stannide heterostructure.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

Development and Validation of CT-Based Dose-Volume-Radiomics Nomogram for Radiation Induced Hypothyroidism in Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

Several studies reported hypothyroidism occurred in 40-50% of patients who were treated with neck irradiation. Post-radiation hypothyroidism impairs quality of life, increases the risk of cardiac complications, and requires lifelong thyroxine replacement in affected patients. At present, radiation dose-volume constraints of thyroid gland are used to predict thyroid function outcomes in patients with nasopharyngeal carcinoma (NPC). However, it is limited by (a) inferior predictive power, (b) a lack of analyzing individualized thyroid characteristics as a categoriad to predict radiation induced hypothyroidism (RIHT). In this study, we firstly developed and validated CT-based dose-volume-radiomics nomogram to predict RIHT in patients with NPC.

MATERIALS/METHODS

A total of 451 NPC patients who underwent definitive radiotherapy were randomly assigned into the training (n = 338) and validation set (n = 113) in a 3:1 ratio. Dose-volume parameters, including the thyroid volume, mean dose (Dmean), percentage of the volume that received xGy of radiation (Vx), and the absolute volume that was spared from xGy of radiation (Vsx), were collected from radiotherapy planning databases. We defined primary hypothyroidism as an elevated TSH serum level (> 4.94 mIU/L) in combination with a normal or low serum FT4 level, regardless of symptoms. 1316 CT radiomic features were extracted and selected to construct the radiomics signature (RS). A CT-based nomogram was established by integrating clinical factors, dose-volume parameters and radiomics signature in training set and was tested in validation set.

RESULTS

With a median follow-up period of 68 months, 301 (66.7%) patients developed RIHT. Compared with other dose-volume parameters including thyroid volume, V30, V50, Dmean, Vs45, Vs50, the thyroid volume spared from 60Gy (Vs60) had best power to predict RIHT. The radiomics signature constructed by 8 selected radiomic features showed better prognostic performance than Vs60 for predicting RIHT in training set (RIHT vs. Vs60, C-index: 0.69 vs. 0.58) and internal validation set (C-index: 0.65 vs. 0.55). Patients were stratified into high- and low-risk groups by median radiomic signature. Patients in high-risk group had higher rate of RIHT than patients in low-risk group (training set:61% vs.39%, P<0.05; validation set: 73% vs.32%, P<0.05). The nomogram established by integrating radiomics signature with Vs60 showed optimal prognostic performance with C-index of 0.71 in training, 0.66 in validation set. Calibration curves showed good agreement.

CONCLUSION

CT-based dose-volume-radiomics nomogram provided an excellent prognostic tool for predict incidence rate of RITH in patients with NPC received definitive radiotherapy.

The Role and Mechanism of Ferroptosis Mediated by METTL3-m6A Modification in Regulating Radioresistance of Esophageal Cancer

PURPOSE/OBJECTIVE(S)

Radioresistance remains the major cause of recurrence within two years after radical radiotherapy in approximately 50% of patients with esophageal cancer (ESCC). Recently, it has been reported that enhancing ferroptosis can reverse tumor radioresistance. However, the underlying mechanisms remain elusive. The aim of this study was to elucidate the role and mechanism of ferroptosis mediated by METTL3 N6-methyladenosine (m6A) modification in regulating radioresistance of Esophageal Cancer. We hypothesize that inhibition of ferroptosis confers radioresistance in Esophageal Cancer by METTL3-induced m6A modification which increase the expression of m6A in the 3'UTR region of SOCS6 and inhibits its expression.

MATERIALS/METHODS

To explore the relationship between radioresistance and ferroptosis. Firstly, ferroptosis was analyzed by 4-HNE staining in ESCC specimens; Furthermore, cell death was detected by propidium iodide (PI) or SYTOX Green staining combined with microscopy or flow cytometry in ESCC radioresistance cells and parental cells, and Iron Assay Kit,C11-BODIPY were used to examine whether ferroptosis were inhibited in radioresistance cells. Subsequently, MeRIP-seq and MeRIP-PCR were performed for discussing the relationship between ferroptosis and m6A. Finally, Mettl3 depleted cells were generated with CRISPR/Cas9-mediated knockout system. Then, m6A methylation level, sensitivity to radiation and ferroptosis of Mettl3 depleted cells by EpiQuik m6A RNA methylation quantification kit, colony formation, C11-BODIPY and Western Blot.

RESULTS

Firstly, we found that the level of lipid peroxide 4-HNE in ESCC samples that recurred after radical radiotherapy was significantly lower than that in radiotherapy (40Gy), and the ferroptosis of radioresistance cells was inhibited. MeRIP-seq found that the level of m6A in radioresistance cells increased significantly, and then the KEGG pathway analysis of MeRIP-seq results showed that hypermethylation of m6A was closely related to ferroptosis signal pathway. and we also found that the level of m6A was significantly decreased by adding agonist (Erastin), whereas the modification level was significantly increased by adding inhibitor Fer-1. Meanwhile, we found that the level of m6A was significantly decreased in radioresistance cells silencing METTL3, while the ferroptosis was activated, which caused the radiosensitivity of ESCC. Lastly, MeRIP-PCR data showed that METTLT3 induced a significant increase in m6A level in 3' UTR region of SOCS6 mRNA and inhibited its expression, which eventually led to radioresistance of ESCC.

CONCLUSION

m6A-regulated ferroptosis inhibition confers radioresistance of ESCC. METTL3 up-regulated m6A in SOCS6 3' UTR and inhibited the expression of SOCS6, which caused the inhibition of ferroptosis.

Dosimetric Validation of 3D-Printed Bolus at Different Printing Infill Percentage in VMAT Plan

PURPOSE/OBJECTIVE(S)

The 3D printed bolus technology is rapidly evolving in external beam radiotherapy and printing parameters can have a significant impact on absorbed dose. In this study, a novel 3D printed bolus was designed to evaluate the time and material cost effects, dosimetry differences, and surface dose modulation capabilities in the volumetric-modulated arc therapy (VMAT) plan at different print filling percentages.

MATERIALS/METHODS

A hollow-type bolus, the middle 2.36 mm of 5 mm thickness infilled with different ratio, was designed and printed with polylactic acid (PLA). The ratio of printed material was defined by the infill percentage parameter ranging from 10% to 90%. For each bolus, two treatment plans were designed with AAA algorithm, considering the real computed tomography (CT) scan of the 3D printed bolus and modeling the 3D printed bolus as a virtual bolus structure. Percentage depth dose (PDD) profiles were calculated to build up the mapping equivalent CT value in treatment plan system (TPS). Measurement dose was performed by radiographic films. The PDD profiles were then compared between measured and calculated. A simulation VMAT treatment plan with planning target volume (PTV) close to the body surface was designed on a water-equivalent phantom, and the modulation capabilities of epidermal dose under different filling percentage was compared.

RESULTS

Compared with 100% percent infill 3D printed bolus, The maximum printing time could be reduced by 47.8% and material consumption could be reduced by 42.5%. The surface dose at single field irradiation can reach 69.6% to 85.8% of the maximum dose in different filling boluses. The PDD measurement and mapping equivalent CT calculation deviation was less than 3% when the infill percentage of the middle region is greater than 30%. The dose distribution of the VMAT plan is satisfying for infill percentages greater than 30%.

CONCLUSION

Using the 3D printing technology is possible to modulate the amount of shift of the build-up region by tuning the infill percentage of the 3D printed bolus. Patients could undergo CT simulation without bolus. Appropriate bolus could be selected according to the location of the PTV region and dose requirement.

Induction Immunotherapy vs. Consolidation Immunotherapy for Unresectable Stage III NSCLC

PURPOSE/OBJECTIVE(S)

Consolidation immunotherapy after chemoradiotherapy (CRT) is the standard of care for unresectable stage III non-small cell lung cancer (NSCLC). However, whether upfront immunotherapy before CRT has similar benefits has not been addressed. This study aimed at exploring the efficacy and safety of induction immunotherapy for unresectable stage III NSCLC through real-world data.

MATERIALS/METHODS

Patients diagnosed with stage III NSCLC who received immunotherapy in combination with sequential (sCRT) or concurrent CRT (cCRT) between November 2018 and December 2021 were retrospectively identified. Patients were divided into induction (Ind), consolidation (Con) and induction plus consolidation (Ind+Con) immunotherapy groups. Progression-free survival (PFS) and overall survival (OS) were assessed from the initiation of treatment and estimated by Kaplan‒Meier method. The potential factors affecting PFS and OS were analyzed by univariate and multivariate Cox regression models.

RESULTS

One hundred and two patients were included, with 52 (51.0%) patients in the Ind group, 35 (34.3%) in the Con group and 15 (14.7%) in the Ind+Con group. Median PFS was 24.0 months vs. 36.0 months vs. 19.0 months in the three groups, and 2-year PFS were 43.0% vs 51.1% vs 44.4% (p = 0.940). Median OS was not reached (NR) vs. 44.0 months vs. NR, with a 2-year OS rate of 80.5% vs. 84.4% vs. 86.2% (p = 0.861). In the cCRT setting, 2-year PFS rates were 56.7% vs. 71.6% vs. 100.0% (p = 0.439), 2-year OS rates were 92.3% vs. 89.3% vs. 100.0% in the three groups (p = 0.827). In multivariate analysis, elder (HR = 0.487, p = 0.037) and cCRT (HR = 0.282, p = 0.001) were the independent factors favoring PFS, while only elder (HR = 0.088, p = 0.021) was the independent factors favoring OS. Adverse events were similar in the three arms. Further analysis found the objective response rate (ORR) and disease control rate (DCR) in the Ind and Ind+Con group after induction immunotherapy were 59.7% and 98.5%, respectively. Only 1 (1.5%) patient developed progression. Subgroup analysis showed no significant difference in PFS (p = 0.520) and OS (p = 0.116) between patients who responded to induction immunotherapy (PR+CR) and those who did not (SD+PD). Patients with <4 cycles of induction immunotherapy exhibited numerically better PFS than those with ≥4 cycles of induction immunotherapy (p = 0.113) and improved OS (p = 0.021).

CONCLUSION

Induction immunotherapy may achieve similar survival benefits to consolidation immunotherapy, and the combination of induction and consolidation immunotherapy with cCRT appears to achieve better outcomes. It seems feasible and safe to upfront immunotherapy before CRT, and further investigations on the combination of induction immunotherapy and CRT are warranted.

A Retrospective Analysis of Immediate Postoperative Electron Radiotherapy for Keloids

PURPOSE/OBJECTIVE(S)

The increasing incidence of keloid has seriously affected people's physical and mental health, and the postoperative recurrence rate is as high as 50-80%. Postoperative radiotherapy has been shown to significantly reduce the recurrence of keloid. Given the different treatment patterns in different institutions, we tried to analyze the data of patients in our center.

MATERIALS/METHODS

We retrospectively analyzed the clinical data of 455 patients with 498 keloids treated in our institution from 2010 to 2017. All patients received a four-fraction electron radiotherapy with single dose of 4 Gy within 24 hours of surgery. The recurrence and adverse reaction of immediate adjuvant radiotherapy in these patients was evaluated.

RESULTS

At the last follow-up date, 130 (26.5%) keloids had recurred after a middle follow-up of 68.1 months (42.6-129.9 months). The recurrence rates of 1 year, 3 years and 5 years were respectively14.5%, 18.7% and 21%. Recurrence rates vary depending on the keloid location. Among them, the recurrence rate of ear was low with 14% (43/298). Face, head neck and limbs was moderate with 38.8% (17/44) and 33.3% (8/24). Chest and Suprapubic region had a high recurrence rate of 50.8% (32/64) and 47.8% (33/69). Among the patients with recurrence, 16.9% (22/130) felt that their symptoms were better than before treatment, and 37.7% (49/130) were not worsen, which was acceptable. Multivariate analysis showed that age and duration of postoperative pruritus pain were correlated with recurrence (P = 0.036; P = 0.02). Radiotherapy combined with steroid and silicone reduced the recurrence rate compared with radiotherapy alone (P = 0.015). During treatment and follow-up, Infection occurred in 2 patients and cutaneous fibroblastoma in 1 patient.

CONCLUSION

Our radiotherapy regimen can effectively reduce the recurrence rate and improve the symptoms of patients with keloids, especially ear keloids. High recurrence sites need further improvement of radiotherapy dose and fraction. Combination of multiple treatments is better than single treatment.

High Dose Hyperfractionated Thoracic Radiotherapy vs. Standard Dose for Limited Stage Small-Cell Lung Cancer: A Multicenter, Open-Label Randomized, Phase 3 Trial

PURPOSE/OBJECTIVE(S)

Limited stage small-cell lung cancer (LS-SCLC) is associated with poor prognosis. We aimed to assess the efficacy and safety of high-dose, hyperfractionated thoracic radiotherapy of 54 Gy in 30 fractions compared with standard dose (45 Gy in 30 fractions) as a first-line treatment for LS-SCLC.

MATERIALS/METHODS

The study was an open-label, randomized, phase 3 trial, done at 16 public hospitals in China. Key inclusion criteria were patients aged 18-70 years, with previously histologically or cytologically confirmed LS-SCLC, previously untreated or received 1-2 courses of intravenous cisplatin (75 mg/m²of body-surface area, on day 1 or divided into two days of each cycle) or carboplatin (area under the curve of 5 mg/mL per min, day 1 of each cycle)and intravenous etoposide (100 mg/m²of body-surface area, on days 1-3 of each cycle), and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.Eligible patients were randomly assigned (1:1) to receive volumetric-modulated arc radiotherapy (VMAT) of 45 Gy in 30 fractions or the simultaneous integrated boost VMAT (SIB-VMAT) of 54 Gy in 30 fractions to the primary lung tumor and lymph node metastases starting 0-42 days after the first chemotherapy course. Both groups of patients received thoracic radiotherapy twice per day and 10 fractions per week. Prophylactic cranial radiation (PCI, 25 Gy in 10 fractions) was implemented to patients with responsive disease. The primary endpoint was overall survival. Safety was analyzed in the as-treated population.

RESULTS

Between June 30, 2017, and April 6, 2021, 224 eligible patients were enrolled and randomly assigned to 54 Gy (n = 108) or 45 Gy (n = 116). Median follow-up for the primary analysis was 45 months (IQR 41-48). Median overall survival was significantly improved in the 54 Gy group (62.4 months) compared with the 45 Gy group (43.1 months; p = 0.001). Median progression-free survival was significantly improved in the 54 Gy group (30.5 months) compared with the 45 Gy group (16.7 months; p = 0.044). The most common grade 3-4 adverse events were neutropenia (30 [28%] of 108 patients in the 54 Gy group vs 27 [23%] of 116 patients in the 45 Gy group), neutropenic infections (6 [6%] vs 2 [2%]), thrombocytopenia (13 [12%] vs 12 [10%]), anemia (6 [6%] vs 4 [3%]), and esophagitis (1 [1%] vs 3 [3%]). Treatment-related serious adverse events occurred in 9 [8%] patients in the 54 Gy group and 16 [14%] patients in the 45 Gy group. There were one treatment-related deaths in 54 Gy group (myocardial infarction).

CONCLUSION

Compared with standard thoracic radiotherapy dose of 45 Gy, the high dose of 54 Gy improved overall survival and progression-free survival without increasing toxicities in patients with LS-SCLC, supporting twice-daily hyperfractionated thoracic radiotherapy of 54 Gy with concurrent chemotherapy is an alternative treatment option for LS-SCLC. This study is complete and registered with ClinicalTrials.gov, NCT03214003.

Long-Term Results of Induction Chemotherapy for Esophageal Squamous Cell Carcinoma Receiving Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to investigate the long-term clinical outcomes and toxicities of induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) versus CCRT alone in patients with esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Between 2008 and 2022, 271 ESCC patients who received definitive CCRT (IC followed by CCRT, n = 72; CCRT alone, n = 199) were enrolled. Radiotherapy technique included intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT). Through a propensity score matched (PSM) method, 71 patients receiving IC and CCRT were matched 1:1 to patients who received CCRT alone, according to age, gender, performance status, tumor length, and pre-treatment TN stage. The Kaplan-Meier method and Cox proportional hazards model were applied to analyze survival and prognosis.

RESULTS

The IC + CCRT group had no improvement in 5-year overall survival (OS) rate (39.0% vs 29.3%, p = 0.360), recurrence-free survival (RFS) rate (39.0% vs 26.9%, p = 0.142), and distant metastasis-free survival (DMFS) rate (33.6% vs 27.2%, p = 0.515) compared with the CCRT group. The overall clinical response rate was 45.1% after IC in the IC + CCRT group. The IC responders (CR + PR + SD) group showed more favorable 5-year OS (41.7% vs. 14.3% vs. 29.3%, p < 0.001), RFS (41.7% vs. 14.3% vs. 26.9%, p < 0.001) and DMFS (37.3% vs. 0% vs. 27.2%, p < 0.001) compared with the IC non-responders (PD) group and the CCRT group. Besides, the 5-year OS rate (65.6% vs. 17.6% vs. 29.3%, p < 0.001), RFS rate (65.6% vs. 17.6% vs. 26.9%, p < 0.001), and DMFS rate (62.5% vs. 10.3% vs. 27.2%, p < 0.001) of the IC good responders (CR + PR) were significantly higher than that of the IC poor responders (SD + PD) and CCRT group. Multivariate analysis revealed that total radiotherapy time (≥ 49 days) and AJCC stage (Ⅲ/Ⅳ) were independent predictive factors of OS, RFS and DMFS. Besides, age was an independent predictive factor of DMFS. No significant difference was observed in the rates of grades 3-4 toxicities between both groups.

CONCLUSION

Our results showed the addition of IC to CCRT was not superior to CCRT in unselected ESCC patients, while IC responders could benefit from this regime without increase in toxicities.

Pseudo CT Images Synthesized from CBCT Based on Unsupervised DDPM in Cervical Cancer Radiotherapy

PURPOSE/OBJECTIVE(S)

The low image quality and inaccurate HU value of cone beam computed tomography (CBCT) restrict its further application in cervical cancer radiotherapy. A new unsupervised based denoising diffusion probabilistic model (DDPM) was proposed to synthesize pseudo-CT images from CBCT.

MATERIALS/METHODS

CBCT and CT images of 120 patients with cervical cancer were selected. The proposed DDPM network with condition and iterative mechanism was used for data training and testing between two image domains. In the training process, the model first obtained coarse pseudo-CT images with Gaussian noise through a diffusion process. Then, with the real CT images as the training target, the noise images were nonlinearly mapped to the domain of the CT images through the inverse diffusion process, and the fine pseudo-CT images were obtained. We repeated the above steps and gradually increased the number of noise diffusion. When the image difference value is less than the threshold, the training of the model is terminated and the pseudo-CT images are output. In the testing stage, each pseudo-CT generated was compared against the real CT image of the same patient based on the metrics of peak signal-to-noise ratio (PSNR), structural similarity index (SSIM) and normalized mean absolute error (NMAE).

RESULTS

In terms of anatomical verification, the PSNR (dB), SSIM (%) and NCC values between the pseudo-CT images obtained based on DDPM and the real CT images were presented as mean (standard deviation), which were 31.92(0.46), 86.69(4.55) and 0.0106(0.002) respectively. Compared with CBCT, the accuracy of the three metric values has been improved 15.6%, 14.2% and 23.3% respectively. For the metric values of the pseudo-CT images obtained based on the U-Net and CycleGAN models, the results synthesized based on the proposed model were paired with T-tests, the p values were all less than 0.05, and the differences were statistically significant.

CONCLUSION

The pseudo-CT images obtained based on the DDPM were close to the real CT images in anatomy. The pseudo-CT images synthesized by the proposed DDPM network have good application prospects in cervical cancer radiotherapy.

Introducing an Experimental Approach to Predict Spot Scanning Time Parameters for a Superconducting Cyclotron Proton Therapy Machine

PURPOSE/OBJECTIVE(S)

Proton pencil beam scanning (PBS) delivery sequence varies a lot among institutions due to the differences in vendors, machine types, and beamline configurations, which impacts PBS interplay effects and treatment delivery time estimation. This study aims to develop an independent experimental approach to predict the spot scanning time parameters for a clinical superconducting cyclotron proton therapy machine.

MATERIALS/METHODS

This independent experimental approach employed an open-air parallel-plate detector with a temporal resolution of 0.05ms. A series of spot, energy, and dose rate patterns were designed and delivered, including (1) Spot switching time (SSWT) under different spot spacing for IEC-X, IEC-Y directions and diagonal direction (traveling in both X and Y direction) for three energy layers (110, 170 and 230 MeV); The Wilcoxon test is used to validate the prediction of SSWT along the diagonal direction. (2) Energy layer switching time (ELST) with different descending energy gaps for a fixed initial energy and different initial energies for a fixed descending energy gap. (3) Dose rate (MU/min) are measured for different minimum-MU-per-energy-layer (MMPEL), which are compared with the previous publication.

RESULTS

A SSWT jump at 10mm (can be customized) spot spacing is observed because of triggering the machine's "raster mode" threshold. Discontinuous two variable piecewise linear functions were used to fit the SSWT in X/Y for spot spacing and energy. SSWT in X/Y is increasing as spot spacing and energy increase. SSWT in the diagonal direction is determined by the time either in the x-direction or y-direction, whichever takes longer (see Table 1 for one example of validations). ELST is linear depending on descending energy gap. The dose rate dependence on MMPEL is confirmed with previous publications of a similar type of machine.

CONCLUSION

The study provided the first independent quantitative experimental modeling of the beam delivery time parameters without any information from vendors. Such machine-specific delivery sequence models could pave the foundation of precise interplay effect evaluation for clinical decision-making.

Deep Learning-Based Dose Prediction Model for Automated Spot-Scanning Proton Arc Planning

PURPOSE/OBJECTIVE(S)

Spot-scanning proton arc (SPArc) is a novel technique that employs a planning optimization algorithm to select the energies and positions of spots along a dynamic rotational arc trajectory. The SPArc technique has the potential to achieve superior dose conformality and treatment delivery efficiency over intensity-modulated proton therapy. However, creating such a SPArc plan using existing approaches is time-consuming and computationally extensively. This study investigated the feasibility of using the deep learning (DL) technique to predict the 3D dose distribution of the SPArc treatment plan, leveraging the prior knowledge acquired from conventional intensity-modulated radiation therapy (IMRT) plans.

MATERIALS/METHODS

A DL model, 3D-Unet with residual connections and attention gates, was trained using an open-source database of CT images, critical structures, and IMRT plans from 340 head and neck cancer patients (HNC) as the base model. Transfer learning technique was applied to fine-tune the model parameters using the SPArc treatment plans created on the HNC patients from an in-house dataset, where the SPArc treatment plans (including control point sampling, energy layer distribution, arc trajectory, etc.,) were optimized using a previously developed iterative approach. The performance of the DL model was evaluated by comparing predicted and planned doses over 17 SPArc treatment plans by using 4-fold cross-validation.

RESULTS

The SPArc planning time per patient was 8∼12 hours, while the dose prediction time was reduced to 2∼3 minutes using the proposed DL model. The deviation of D95 in the target was (-1.8±1.6) %. The deviation of the mean dose in the parotids, cord, mandible, and brainstem were (2.5±6.5) %, (-0.5±4.3) %, (1.4±3.9) %, and (3.4±8) % of the prescription, respectively. The dice similarity coefficients of the 80%, 70%, and 60% isodose lines were (0.9±0.09), (0.93±0.01), and (0.94±0.01), respectively.

CONCLUSION

Our results demonstrate that a DL-based dose prediction model can be created with a limited number of SPArc treatment plans through transfer learning. The DL model can directly predict the 3D dose distribution in minutes for automated planning. This study paves the roadmap to develop a quick clinical decision platform for the optimal selection among the multi-treatment modalities.

A Novel Planning and Delivery Technology: Dose, Dose Rate and Linear Energy Transfer (LET) Optimization Based on Spot-Scanning Proton Arc Therapy FLASH (SPLASHLET)

PURPOSE/OBJECTIVE(S)

To achieve a high conformal dose with Linear Energy Transfer (LET) optimized FLASH proton therapy, we introduced a new planning and delivery technique concept, the voxel-wised optimization of LET distribution and dose rate based on scanning arc therapy (SPLASHLET) MATERIALS/METHODS: The algorithm optimizes (1) the clinical dose-volume constraint based on dose distribution and (2) the clinical LET-volume constraint based on LET distribution using Alternating Direction Method of Multipliers (ADMM) with Limited-memory BFGS solver by minimizing the monitor unit (MU) constraint on spot weight and (3) the effective dose-average dose rate by minimizing the accelerator's beam current sequentially. Such optimization framework enables the high dose conformal dynamic arc therapy with the capability of LET painting with voxel-based FLASH dose rate in an open-source proton planning platform (MatRad, Department of Medical Physics in Radiation Oncology, German Cancer Research Center-DKFZ). It aiming to minimize the overall cost function value combined with plan quality and voxel-based LET and dose rate constraints. Three representative cases (brain, liver and prostate cancer) were used for testing purposes. Dose-volume histogram (DVH), LET volume histogram (LVH) dose rate volume histogram (DRVH) and dose rate map were assessed compared to the original SPArc plan (SPArcoriginal).

RESULTS

SPLASHLET plan could offer comparable plan quality compared to SPArcoriginal plan. The DRVH results indicated that SPArcoriginal could not achieve FLASH using the clinic beam current configuration, while SPLASHLET could significantly not only improve V40Gy/s in target and region of interest (ROI) but also improve the mean LET in the target and reduce the high LET in organ at risk (OAR) in comparison with SPArcoriginal (Table 1).

CONCLUSION

SPLASHLET offers the first LET painting with voxel-based ultra-dose-rate and high-dose conformity treatment using proton beam therapy. Such technique has the potential to take full vantage of LET painting, FLASH and SPArc.

Re-Irradiation for Locally Primary Recurrence in Esophageal Squamous Cell Carcinoma Treated with IMRT/VMAT

PURPOSE/OBJECTIVE(S)

Locally primary recurrence of esophageal squamous cell carcinoma (ESCC) after definitive treatment has the potential for increasing overall survival with re-irradiation (Re-RT), especially with advanced technique. This study aimed to evaluate the efficacy and toxicities of Re-RT using intensity-modulated radiotherapy (IMRT)/volumetric modulated arc therapy (VMAT) for local primary-recurrence of ESCC.

MATERIALS/METHODS

A total of 130 ESCC patients with local primary-recurrence from Xijing hospital between 2008 and 2021 were enrolled and 30 patients underwent IMRT/VMAT based salvage Re-RT. Cox regression analysis was used to analyze the prognostic factors for overall survival (OS) and after recurrence survival (ARS). The toxicities of 30 patients receiving Re-RT were also assessed.

RESULTS

The median OS and ARS of the 130 recurrent patients were 21 months (1-164 months) and 6 months (1-142 months). The 1-, 2-, and 3-year OS rates were 81.5%, 39.2%, and 23.8%, respectively. Besides, the 1-, 2-, and 3-year ARS rates were 30.0%, 10%, and 6.2%. Multivariate analysis showed that Re-RT ± chemotherapy (p = 0.043) and chemotherapy alone (p < 0.001) and esophageal stents (p = 0.004) were independent prognostic factors for OS. The median OS of 30 patients treated with Re-RT were significantly better than that of 29 patients treated with chemotherapy (34.5 months vs. 22 months, p = 0.030). Among 30 ESCC patients treated with Re-RT, the median OS and ARS were 34.5 months (range 12-163 months) and 6 months (range 1-132 months), respectively. The recurrence-free interval (RFI) (> 12 months) and initial radiation dose (> 60 Gy) were significantly associated with improved OS. Radiation esophagitis (Grade 1-2) occurred in 16 patients and myelosuppression (Grade1-2) occurred in 10 patients. Grade 3 toxicities (radiation esophagitis and myelosuppression) were only 13.3%. There were no grade 4 toxicities.

CONCLUSION

Our results demonstrated that IMRT/VMAT-based Re-RT was an effective therapeutic option for ESCC patients with local primary-recurrence compared with chemotherapy alone or without any treatment. Re-RT had improved OS but unfavorable ARS.

Mitigation of Dosimetric Uncertainty in MRI-Based Proton Planning Using Spot-Scanning Proton Arc (SPArc) Technique

PURPOSE/OBJECTIVE(S)

MRI-based synthetic CT (SCT) images created using generative adversarial network (GAN) have been demonstrated to be feasible for intensity-modulated proton therapy (IMPT) planning. However, dose calculation accuracy can be uncertain in some regions within/near the target of head and neck patients due to the local CT number estimation error or sharp dose fall-off. This study investigated the feasibility of using the SPArc technique to mitigate such dosimetric uncertainty.

MATERIALS/METHODS

A GAN using a 3D U-net as the generator and a 6-layer 3D convolutional neural network as the discriminator was trained with T1-weighted MR-CT image pairs from 162 nasopharyngeal carcinoma patients (14 for validation). The generator was used to generate SCT images from MR images for 7 test patients. For each test patient, the CT image was used to create a SPArc plan and an IMPT plan with the same clinical objectives. The SPArc plans (control point frequency sampling, arc trajectory, etc.) were optimized using a previously developed iterative approach. The dose distributions of both SPArc plans and IMPT plans were re-calculated on the SCT images and compared to the one calculated on the CT images. The dosimetric uncertainty was quantified using the gamma index.

RESULTS

The 2%/2mm and 3%/3mm passing rates for SPArc plans were (96.9¡À2.7) % and (98.6¡À1.5) %, while the passing rates for IMPT plans were (94.0¡À3.9) % and (96.4+2.9) %. A significant reduction in dosimetric uncertainty was identified for SPArc plans (p ¡Ü0.021). Table 1 shows the passing rates for the 7 test individuals.

CONCLUSION

SPArc can mitigate the uncertainty of dose calculation in MRI-based proton planning. Further research needs to validate these findings on a larger patient cohort. The study paves the road map for using MRI for SPArc planning.

30 Gy vs. 45 Gy Consolidative Thoracic Radiation (cTRT) for Extensive Stage Small Cell Lung Cancer (ES-SCLC): A Multicenter, Randomized, Phase 3 Trial

PURPOSE/OBJECTIVE(S)

Consolidative thoracic radiotherapy (cTRT) showed potential benefit to extensive stage small cell lung cancer (ES-SCLC). However, the optimum dose of cTRT is unknown. The purpose of this randomized trial was to compare the effect of 45 Gy in 15 fractions with 30 Gy in 10 fractions cTRT in ES-SCLC.

MATERIALS/METHODS

This phase III, randomized trial was conducted in 12 public hospitals in China. Eligible patients with pathologically confirmed ES-SCLC who responded to 4-6 cycles of etoposide plus cisplatin (EP) or carboplatin (EC) chemotherapy were randomized 1:1 to receive either 30 Gy in 10 fractions or 45 Gy in 15 fractions cTRT. The primary outcome was 2-year overall survival (OS). Secondary outcomes included 2-year progression-free survival (PFS), 2-year local control (LC) and radiation treatment related toxicity. The primary objective was to detect an OS improvement in 45 Gy cTRT group at 2 years from 13% to 26% assuming a two-sided a = 0.05 and power of 85%, with a planned sample size of 186 patients. This trial was registered with Clinical Trials.gov, number NCT02675088.

RESULTS

Between January 15, 2016, and September 20, 2022, 90 patients were randomly assigned either 30 Gy in 10 fractions (n = 50) or 45 Gy in 15 fractions (n = 40) cTRT group. Recruitment to the trial closed early due to slow accrual since first-line chemoimmunotherapy has become the new standard of care for ES-SCLC. The median age of patients was 58 years, 87.8% were male, 76.7% had a smoking history, 95.6% received IMRT, and 58.9% received prophylactic cranial irradiation. At a median follow-up of 39.9 months (IQR 27.2-59.2), there was no significant difference in the 2-year OS between the 45 Gy group and the 30 Gy group, at 43.4% (95% CI 29.3%-64.3%) and 40.0% (95% CI 27.9%-59.1%), respectively (log-rank p = 0.62; HR 1.13 [95% CI 0.69-1.84]). The 2-year PFS was 12.1% (95% CI 4.3%-33.8%) in the 45 Gy group and 9.0% (95% CI 3.2%-25.2%) in the 30 Gy group (log-rank p = 0.25, HR 0.76(95% CI [0.478-1.22]). There were also no significant differences in locoregional recurrence free survival (log-rank p = 0.75; HR 0.888 [95% CI 0.423-1.863]) and distant metastasis free survival (log-rank p = 0.95; HR 1.015 [95% CI 0.624-1.651]) between two groups. No grade 5 toxicity was observed in both groups. Patients treated with higher cTRT dose presented with increased incidence of grade 3+ radiation pneumonitis (10% vs 2%) and hematological toxicity (20% vs 12.5%).

CONCLUSION

This randomized trial did not find a higher probability of survival improvement in patients with ES-SCLC receiving cTRT of 45 Gy in 15 fractions compared with 30 Gy in 10 fractions. In contrast, there was an increase in toxicity, especially radiation pneumonitis. Additional randomized studies investigating the role of cTRT in ES-SCLC after a response to chemoimmunotherapy are warranted.

Primary Small Cell Carcinoma of the Esophagus in a Large Multicenter Cohort: Prognostic Factors and Treatment Strategies in the Modern Era

PURPOSE/OBJECTIVE(S)

Primary small cell carcinoma of esophageal (PSCCE) is a rare malignancy with aggressive behavior associated with a perceived poor prognosis. Due to its rarity, the clinical characteristics and the optimal clinical management have not yet been defined, therefore, we designed a multicenter retrospective study to analyze the prognostic factors and the impact of treatment on the prognosis of PSCCE patients.

MATERIALS/METHODS

We retrospectively evaluated 704 consecutive patients with PSCCE from five participating centers between April 2008 and July 2021. The PSCCE was diagnosed based on the World Health Organization classification. Treatment strategies included surgery, radiotherapy (RT), or chemotherapy only, and combination of 2-3 treatment modalities (surgery, RT and chemotherapy). The estimated hazard rates provide the trajectory of progression and death overtime. Univariate survival analysis was conducted by using Kaplan-Meier plots, and the log-rank test was used to compare survival differences. Cox regression analysis was used to determine the independent prognostic factors in multivariate analysis.

RESULTS

Overall, 69.0% (486/704) of the patients were male, with a median age of 63 years (range 38-96). Most of the patients were regional lymph node positive (N+, 64.0%), and nearly half with advanced stage (M+, 47.2%). With a median follow-up time of 16 months, 472 patients (67.0%) exhibited disease progression and 429 patients (60.9%) died. Following initial treatment, 85.1% (402/472) of progression/death and 80.1% (344/429) of mortalities occurred within 24 months. Consistently, the maximum annual death and progression/death hazards are highest in the 15.6 months and 9.6 months. The overall survival (OS) rates at 1, 3 and 5 years for all patients were 65.1%, 26.5% and 18.3%, respectively. Univariate survival analysis showed that ECOG score, alcohol abuse, TNM stage, N stage, and M stage were correlated with OS (P <0.05). Multivariate analysis showed that the N stage (HR: 1.378, P = 0.018) and M stage (HR: 1.945, P <0.001) carried independent prognostic factors for OS. In the term of treatment, the OS rates for M- patients treated with combined modality therapy (CMT, surgery±radiotherapy/chemotherapy) were better than those treated with surgery alone or radiotherapy/chemotherapy (3-year OS: 36.7% VS 25.6% VS 32.2%; P = 0.045). The OS rates for M+ patients treated with chemotherapy alone, radiotherapy alone, or radiotherapy combined with chemotherapy were no significant differences (3-year OS: 12.2% VS 19.4% VS 11.1%; P = 0.400).

CONCLUSION

PSCCE is characterized by a high degree of malignancy with high risks of lymphatic and distant metastasis, N and M stages are the most important prognostic factor. In terms of treatment, comprehensive treatment is most likely to benefit patients without distant metastasis.

First Demonstration of the Commissioning of a New Multi-Modality Radiotherapy Platform

PURPOSE/OBJECTIVE(S)

A new multi-modality radiotherapy platform was developed and introduced into clinical application, which has received US FDA 510k(K210921) and National Medical Products Administration (NMPA) clearance in China (20223050973). This study, for the first time, presents the technological characteristics and commissioning results of the new platform.

MATERIALS/METHODS

The platform consists of 3 modules: linear accelerator, rotating gamma system, and a kV imaging system within an O-ring gantry. The O-ring gantry can rotate continuously achieved by using a slip ring. The Linac delivers a 6 MV FFF photon beam with a variable dose rate of 50 to 1400 MU/min. The delivery techniques include 3D-CRT, IMRT, and VMAT. The rotating gamma system utilizes 18 Co-60 sources with a reference dose rate of 350 cGy/min. The image-guided techniques consist of kV-kV pairs and kV-CBCT. The X-ray intensity-modulated radiotherapy and γ-ray stereotactic radiotherapy can be delivered on the same platform. The acceptance test and commissioning were performed following the vendor's customer acceptance tests (CAT) and several AAPM Task Group reports/guidelines. Regarding the Linac, all applicable validation tests recommended by the MPPG 5.a (basic photon beam model validation, IMRT/VMAT validation, E2E tests, and patient-specific QA) were performed. For the rotating gamma system, the absorbed doses were measured using a PTW31014 and PTW60016. EBT3 films were employed to measure the relative output factors (ROFs). The E2E tests were performed using a PTW31014 and EBT3 films. The coincidence between the imaging isocenter and the Linac/gamma treatment isocenter was investigated using EBT3 films. The image quality was evaluated regarding the contrast-to-noise ratio (CNR), spatial resolution, and uniformity.

RESULTS

All tests included in the CAT met the vendor's specifications. All MPPG 5.a tests complied with the tolerances. The confidence limits for IMRT/VMAT validation were achieved according to TG-119. The point dose differences were below 1.68% and gamma pass rates (3%/2 mm) were above 95.9% for the Linac E2E tests. All plans of patient-specific QA had point dose differences below 1.79% and gamma pass rates (3%/2 mm) above 96.1% suggested by TG-218. For the rotating gamma system, the differences between the calculated and measured absorbed doses were below 1.86%. The ROFs calculated by the TPS were independently confirmed within 2% using EBT3 films. The point dose differences were below 2.57% and gamma pass rates (2%/1 mm) were above 95.3% for the E2E tests. The coincidence between the imaging isocenter and the Linac/gamma treatment isocenter was within 0.5 mm. The image quality fully complied with the vendor's specifications regarding the CNR, spatial resolution, and uniformity.

CONCLUSION

This is the first report about the commissioning of a new multi-modality radiotherapy platform. The platform has been successfully commissioned and exhibits good performance in mechanical and dosimetry accuracy.

Development and Validation of CT-Based Clinical-Radiomics Nomogram for Early Stage Extranodal Nasal-Type NK/T Cell Lymphoma: A Multicenter Study

PURPOSE/OBJECTIVE(S)

Most patients with extranodal nasal-type NK/T cell lymphoma (ENKTCL) had a localized disease with extensive primary tumor invasion at diagnosis (70-90%). Several clinical risk indexes, such as nomogram-revised risk index (NRI), international prognostic index (IPI), Korean Prognostic Index (KPI) and prognostic index of natural killer lymphoma (PINK), were used for ENKTCL patient stratification and providing information in clinical decision-making. However, they had low predictive power for early-stage patients with ENKTCL. This is the first study to construct a model with more predictive power through CT-based radiomics signature combined with traditional clinical risk indexes for overall survival (OS) of patients with early-stage ENKTCL.

MATERIALS/METHODS

A total of 196 early stage ENKTCL patients were randomly assigned into the training (n = 147) and interval validation set (n = 49) in a 3:1 ratio. And 83 and 19 early stage ENKTCL patients from other two centers were used for external validation set (n = 62). All patients received radiotherapy after 2-3 cycles of chemotherapy. 1316 CT radiomic features before radiotherapy were extracted and selected to construct the radiomics signature (RS). A CT-based nomogram was established by integrating clinical indexes and radiomics signature in training set and was tested in two validation sets.

RESULTS

With a median follow-up period of 59.9 months, 48 patients (24.1%) died. Compared with other prognostic index, NRI had better power to predict 5-year OS in the training cohort. The radiomics signature constructed by 11 selected radiomic features showed better prognostic performance than NRI for predicting 5-year OS in training set (C-index: 0.75 vs. 0.66), internal validation set (C-index: 0.71 vs. 0.62) and external validation set (C-index: 0.68 vs. 0.60). Patients were stratified into high- and low-risk groups by median radiomic signature. Patients in high-risk group had worse 5-year OS than patients in low-risk group (training set: 92% vs. 65%, P<0.001; internal validation set: 88% vs. 59%, P<0.05; external validation set 90% vs. 60%, P<0.05). The nomogram established by integrating radiomics signature with NRI showed optimal prognostic performance with C-index of 0.77 in training, 0.73 in internal and 0.71 in external validation set. Calibration curves showed good agreement.

CONCLUSION

The clinical-radiomics nomogram integrating CT-based radiomics signature combined with traditional clinical risk index provided an excellent prognostic tool for OS, which could be helpful for personalized risk stratification and treatment in early stage ENKTCL patients.

[Living-donor intestinal transplantation]

Due to advances in surgical techniques, perioperative care, and new immunosuppressive agents, intestinal transplantation has become a valid therapeutic choice for chronic intestinal failure. Intestinal transplantation has been performed most commonly using deceased donation, while less than 2% of which have been from living donation. Living donor intestinal transplantation obtaining a segmental intestinal graft, usually from close relatives. Preliminary results show that acute/chronic rejection rates, postoperative opportunistic infections, and graft versus host disease are significantly reduced after living donor intestinal transplantation, contributing to improved graft and patient survivals. Due to a severe shortage of organ donation, especially in children, living donor intestinal transplantation has increasingly become an important treatment option for patients with chronic intestinal failure in China.

Lymphocyte Count Kinetics and the Effect of Different Radiotherapy Techniques on Radiation-Induced Lymphopenia in Patients with Breast Cancer Receiving Hypofractionated Postmastectomy Radiotherapy

PURPOSE/OBJECTIVE(S)

Radiation-induced lymphopenia (RIL) is associated with poor prognosis in solid tumors. This study aimed to describe the lymphocyte kinetics in patients with breast cancer receiving hypofractionated postmastectomy radiotherapy (RT) and to investigate the association of different RT techniques with RIL.

MATERIALS/METHODS

We assessed 607 patients who received hypofractionated postmastectomy RT for breast cancer in our prospective clinical database from 8 hospitals. All patients received irradiation to the chest wall and supraclavicular fossa. RT techniques included integrated RT with the photon-based intensity modulated techniques to irradiate all target volumes (integrated RT) and a hybrid approach combining photon irradiation to supraclavicular nodes and electron irradiation to the chest wall (hybrid RT). Peripheral lymphocyte counts (PLC) were tested prior to RT (baseline), weekly during RT, at 1, 2 weeks, 3, 6 months after RT, and then every 6 months. Grade 3+ RIL was defined as PLC nadir during RT of <0.5 ×103/ml. Mean PLC was compared by the t test. Univariate, multivariate, and propensity score matching (PSM) analyses were used to evaluate the effect of different RT techniques on grade 3+ RIL.

RESULTS

During RT, 121 (19.9%) of patients had grade 3+ RIL. The PLC started to recover at 1 week and reached baseline levels 1 year after RT. A greater proportion of the patients treated with the integrated RT (90/269, 33.5%) developed grade 3+ PLC compared with those receiving hybrid RT (31/338, 9.2%, P < 0.001). After conducting PSM, multivariate analyses showed lower baseline PLC (HR = 0.15, P<0.001) and RT technique (the integrated RT vs. hybrid RT, HR = 4.76, P<0.001) were independent risk factors for grade 3+ RIL. The PLC in patients receiving the integrated RT after RT were higher than that in those receiving hybrid RT (p<0.05).

CONCLUSION

RT technique affect the risk of and recovery from RIL, which may impact survival. Choosing appropriate RT technique to minimize RIL might be considered to benefit their outcomes.

Quality Assurance in a Phase III, Multicenter, Randomized Trial of POstmastectomy radioThErapy in Node posiTive Breast Cancer with or without Internal mAmmary nodaL Irradiation (POTENTIAL): A Planning Dummy Run

PURPOSE/OBJECTIVE(S)

To report the planning dummy run results of the POstmastectomy radioThErapy in Node posiTive breast cancer with or without Internal mAmmary nodaL irradiation (POTENTIAL) trial-a multicenter, randomized, phase 3 trial-to evaluate postmastectomy radiotherapy, with or without internal mammary nodal irradiation, for patients with high-risk breast cancer.

MATERIALS/METHODS

All participating institutions were provided the contours of the dummy run case, and they generated radiotherapy (RT) plans per protocol guidelines. The plans were reviewed and feedback were provided by the quality assurance team, after which the institutions resubmitted revised plans. The information on beams arrangement, skin flash, inhomogeneity corrections, and protocol compliance was assessed both in the primary and final submission.

RESULTS

Theplans from 26 institutions were included in the analysis. A number of major deviations were found in the primary submission, such as less strict constraint on organs at risk (OARs) V5Gy, and no application of chest wall skin flash. The protocol compliance rates of the dose coverage for the planning target volume of the chest wall (PTVcw), PTV of supra/infraclavicular fossa plus axilla levels I, II, III (PTVsc+ax), and PTV of the IMN region (PTVim) were all significantly improved in the final submission compared with those in the primary submission, which were 96.2% vs. 69.2%, 100% vs. 76.9%, and 88.4% vs. 53.8, respectively. For OARs, the protocol compliance rates of heart Dmean, left anterior descending coronary artery V40Gy, ipsilateral lung V5Gy, and stomach V5Gy were significantly improved.

CONCLUSION

All major deviations were corrected and protocol compliance was significantly improved and of high level in the final submission. Moreover, the variations were reduced. Therefore, a planning dummy run was essential to guarantee good RT plan quality and inter-institutional consistency for multicenter trials.

Efficacy and Safety of Multifraction Stereotactic Radiation Therapy with Volumetric Modulated Arc Therapy Technique for Multiple Brain Metastases

PURPOSE/OBJECTIVE(S)

Multifraction stereotactic radiotherapy (MF-SRT) with volumetric modulated arc therapy (VMAT) is the standard treatment option for patients with multiple brain metastases. VMAT has superior physical accessibility and economic accessibility compared with advanced radiotherapy technologies such as Tomo or Proton radiotherapy. However, existing studies has mainly focused on comparing the dosimetric parameters between distinct radiotherapy techniques. Moreover, single fraction stereotactic radiosurgery is preferentially recommended for treatment of brain metastases with maximum diameter <2cm compared with MF-SRT. There is a lack of clinical results of its efficacy and subgroup analyses according to diameter. Thus, we first report the detailed analysis of clinical results of SRT using VMAT for brain metastases.

MATERIALS/METHODS

This study is a retrospective analysis of SRT for multiple brain metastasis using VMAT. The clinical efficacy of VMAT was evaluated by local control (LC) in 6-months, 1-year, and 2-year.

RESULTS

A total of 63 patients with 214 brain metastases were enrolled. The most common fractionation schemes were 40 Gy/8F and 48 Gy/12F. In all, LC rates at 6-month, 1-year, and 2-year were 95.5%, 90.6%, and 76.8%, respectively. Using univariate and multivariate analyses according to stratification factors including maximum diameter, GTV volume, dose per fraction, fractions, inner structure, and BED (α/β = 10), we found that no factors were associated with 6-month LC, 1-year LC, and 2-year LC. 1-year LC rates for maximum diameter ≥1 and <2, ≥2 and <3, and ≥3 cm were 89.2%, 90.7%, and 95.7%, respectively. The 1-year LC rates for tumors with GTV <3, ≥3 and <5, ≥5 and <10, and ≥10 cc were 87.0%, 91.7%, 94.7%, and 96.6%, respectively. Interestingly, 1year-LC in GTV ≥3 cc tends to higher than those in GTV <3 cc, but there was no significant difference (94.4% vs 87%, P = 0.162). Brain radionecrosis (RN) was the most significant toxicity occurring in 10 (4.7%) out of the 214 treated brain metastases. Among 6 patients with RN, 4 (66.7%) had been treated with tyrosine kinase inhibitors.

CONCLUSION

The use of MF-SRT with VMAT for multiple brain metastases showed a comparable clinical efficacy to other techniques described in the literature. And the LC rate for maximum diameter <2cm treated with MF-SRT VMAT was comparable to single fraction stereotactic radiosurgery as previously reported. The treatment-related toxicity was acceptable.

[Prevalence of obesity and its association with dietary patterns: a cohort study among Tibetan pastoralists in Qinghai Province]

Objectives: To explore obesity prevalence and its association with dietary patterns among Tibetan pastoralists during the urbanization transition in Qinghai Province. Methods: Using an open cohort study design, 1 003 subjects were enrolled at baseline in 2018, 599 were followed up, and 1 012 were newly recruited in 2022. A total of 1 913 adults over 18 years were included in the study, and a questionnaire survey and health examination were conducted. Factor analysis was used to identify dietary patterns, and a mixed-effects model was used to analyze the association between dietary patterns and obesity. Results: From 2018 to 2022, the prevalence rates of overweight, obesity, and central obesity were 27.6%, 33.8%, and 54.6%, respectively. Age-sex-standardized prevalence of obesity and central obesity increased. Three dietary patterns were identified: the modern pattern was characterized by frequent consumption of pork, poultry, processed meat, fresh fruits, sugary drinks, salty snacks, etcetera; the urban pattern was characterized by frequent consumption of refined carbohydrates, beef and mutton, vegetables and eggs, etcetera; and pastoral pattern featured frequent consumption of tsamba, Tibetan cheese, buttered/milk tea, and whole-fat dairy products. After adjusting for demographic characteristics, socioeconomic status, and lifestyle factors, compared with the T1, subjects in the T3 of urban pattern scores were more likely to be overweight (OR=2.09, 95%CI: 1.10-3.95) and overweight/obese (OR=1.23, 95%CI: 1.00-1.51), whereas those in the T3 of pastoral pattern scores had a lower risk of overweight (OR=0.45, 95%CI: 0.24-0.84), obesity (OR=0.81, 95%CI: 0.69-0.95), overweight/obesity (OR=0.75, 95%CI: 0.61-0.91) and central obesity (OR=0.58, 95%CI: 0.38-0.89). Conclusions: Prevalence of obesity and central obesity was high among Tibetan pastoralists during the urbanization transition. Urban dietary pattern was a risk factor for overweight and overweight/obesity, whereas pastoral dietary pattern was a protective factor for overweight, obesity, overweight/obesity, and central obesity. Tailored interventions are needed to improve local people's health.

Prevalence, drivers and surveillance of antibiotic resistance and antibiotic use in rural China: Interdisciplinary study

This study aimed to characterise antibiotic prescribing and dispensing patterns in rural health facilities in China and determine the community prevalence of antibiotic resistance. We investigated patterns and drivers of antibiotic use for common respiratory and urinary tract infections (RTI/UTI) in community settings, examined relationships between presenting symptoms, clinical diagnosis and microbiological results in rural outpatient clinics, and assessed potential for using patient records to monitor antibiotic use. This interdisciplinary mixed methods study included: (i) Observations and exit interviews in eight village clinics and township health centres and 15 retail pharmacies; (ii) Urine, throat swab and sputum samples from patients to identify potential pathogens and test susceptibility; (iii) 103 semi-structured interviews with doctors, patients, pharmacy workers and antibiotic-purchasing customers; (iv) Assessment of completeness and accuracy of electronic patient records through comparison with observational data. 87.9% of 1123 recruited clinic patients were prescribed antibiotics (of which 35.5% contained antibiotic combinations and >40% were for intravenous administration), most of whom had RTIs. Antibiotic prescribing for RTIs was not associated with presence of bacterial pathogens but was correlated with longer duration of infection (OR = 3.33) and presence of sore throat (OR = 1.64). Fever strongly predicted prescription of intravenous antibiotics (OR = 2.87). Resistance rates in bacterial pathogens isolated were low compared with national data. 25.8% of patients reported antibiotics use prior to their clinic visit, but only 56.2% of clinic patients and 53% of pharmacy customers could confirm their prescription or purchase included antibiotics. Diagnostic uncertainty, financial incentives, understanding of antibiotics as anti-inflammatory and limited doctor-patient communication were identified as key drivers of antibiotic use. Completion and accuracy of electronic patient records were highly variable. Prevalence of antibiotic resistance in this rural population is relatively low despite high levels of antibiotic prescribing and self-medication. More systematic use of e-records and in-service training could improve antibiotic surveillance and stewardship in rural facilities. Combining qualitative and observational anthropological methods and concepts with microbiological and epidemiological investigation of antibiotic resistance at both research design and analytic synthesis stages substantially increases the validity of research findings and their utility in informing future intervention development.