Dynamic contrast-enhanced magnetic resonance imaging in cervical cancer: correlation between quantitative parameters and molecular markers hypoxia-inducible factors-1-alpha, vascular endothelial growth factor, and Ki-67

AIM

To investigate whether dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has the potential to non-invasively detect microenvironmental condition by quantitatively measuring blood perfusion, vessel wall permeability, and vascularity, and to elucidate the possible correlations between DCE-MRI quantitative parameters and the expression level of hypoxia, vascularity, and cell proliferation related molecular biomarkers.

MATERIALS AND METHODS

In this prospective single center clinical study, 58 patients diagnosed with cervical cancer underwent DCE-MRI before anticancer treatment were enrolled. Ktrans, Kep, Ve, and Vp were generated from Extended Toft's model. Then patients conducted colposcopy biopsy within 1 week after DCE-MRI. Pretreatment expression levels of HIF-1α, VEGF and Ki-67 were assessed and scored by immunohistochemistry on colposcopy obtained tumor specimens.

RESULTS

In HIF-1α low-expression group, Ktrans (p=0.031) and Kep (p=0.012) values were significantly higher than the high-expression group. In VEGF high-expression group, Ktrans (p=0.044) and Ve values (p=0.021) were significantly higher than the low-expression group. In Ki-67 high-expression group, Ktrans (p=0.026) and Kep (p=0.033) were significantly higher than the low-expression group. Multiple linear regression analyses and Pearson correlation revealed that Ktrans independently negatively correlated with HIF-1α expression, Ve independently positively correlated with VEGF, and Kep independently positively correlated with Ki-67. The area under the ROC curves of Ktrans for HIF-1α, Ve for VEGF, and Kep for Ki-67 were 0.728, 0.743, 0.730, respectively.

CONCLUSION

Our results suggest that DCE-MRI quantitative parameters could be potentially used as imaging markers for non-invasively detecting microenvironmental hypoxia, vascularity and proliferation in cervical cancer patients.

[Experience of mesenteric sector fixation in mesenteric torsion treatment]

Objective: The preliminary results was reported regarding the treatment of mesenteric torsion by mesenteric fixation in the last decade, especially preventing recurrence of mesenteric torsion by mesenteric fan-shaped fixation. Methods: We selected 12 patients who received emergency operation in Chongqing Hospital of the First Affiliated Hospital of Guangzhou University of Chinese Medicine from December 2010 to March 2022. All of them were made a definite diagnose of mesenteric torsion by the preoperative CT scan or exploratory laparotomy. The recurrence of mesenteric torsion will be prevented by taking the operation of mesenteric fan-shaped fixation. This technique is suitable for the patient who is suffering total mesenteric torsion, but enteric necrosis is excluded affirmatively. The operation is consists of the following progress: (1) Exploratory laparotomy to check for necrosis of the bowel and for lesions other than torsion. (2) Mesenteric torsion derotation.(3) Mesenteric linear fixation; the right posterior lower border of the small mesentery (terminal ileal mesentery) is intermittently sutured to the posterior peritoneum of the right lower quadrant to increase the width of the base of the small mesentery. (4) Mesenteric fan-shaped fixation, which is fan-shaped to the lower left and fixed in the posterior peritoneum, shortening the length of the mesentery and further increasing the width of the mesentery and posterior peritoneal fixation. Results: A total of 12 patients with mesenteric torsion were treated by operation for 15 times in all. Among them, 3 cases received resection of most small bowel were performed without recurrence; 3 patients received only derotation for a total of 4 times, 2 cases recurred, 1 of them recurred twice; 4 cases underwent derotation and mesenteric linear fixation,and 1 case recurred. Four patients with derotation and mesenteric fan-shaped fixation recovered well without recurrence. Conclusion: Mesenteric fan-shaped fixation may be an effective operative type to reduce or avoid postoperative recurrence of mesenteric torsion.

Machine Learning-Based Integrated Multiomics Characterization of Colorectal Cancer Reveals Distinctive Metabolic Signatures

The metabolic signature identification of colorectal cancer is critical for its early diagnosis and therapeutic approaches that will significantly block cancer progression and improve patient survival. Here, we combined an untargeted metabolic analysis strategy based on internal extractive electrospray ionization mass spectrometry and the machine learning approach to analyze metabolites in 173 pairs of cancer samples and matched normal tissue samples to build robust metabolic signature models for diagnostic purposes. Screening and independent validation of metabolic signatures from colorectal cancers via machine learning methods (Logistic Regression_L1 for feature selection and eXtreme Gradient Boosting for classification) was performed to generate a panel of seven signatures with good diagnostic performance (the accuracy of 87.74%, sensitivity of 85.82%, and specificity of 89.66%). Moreover, seven signatures were evaluated according to their ability to distinguish between cancer and normal tissues, with the metabolic molecule PC (30:0) showing good diagnostic performance. In addition, genes associated with PC (30:0) were identified by multiomics analysis (combining metabolic data with transcriptomic data analysis) and our results showed that PC (30:0) could promote the proliferation of colorectal cancer cell SW480, revealing the correlation between genetic changes and metabolic dysregulation in cancer. Overall, our results reveal potential determinants affecting metabolite dysregulation, paving the way for a mechanistic understanding of altered tissue metabolites in colorectal cancer and design interventions for manipulating the levels of circulating metabolites.

[A survey on the implementation of cardiovascular surgery for congenital heart disease in China between 2017 and 2021]

Objective: To investigate the inplementation of cardiovascular surgery for congenital heart disease (CHD) in China. Methods: A cross-sectional study was carried out. The CHD cardiovascular surgery data collected by the Chinese Society of Extracorporeal Circulation from 2017 to 2021 in 31 provinces (autonomous regions/municipalities) of China were retrospectively reviewed, the implementation of CHD cardiovascular surgery in different provinces, regions, general/specialized hospitals, and different age groups (whether≤18 years old) were summarized, and the correlation analysis between the number of surgeries carried out in each province/region and the gross regional product and the number of the regional population was performed. Results: Between 2017 and 2021, the annual volume of CHD cardiovascular surgery was 77 120, 77 634, 81 161, 62 663 and 71 492, respectively, showing a decreasing trend. Meanwhile, the proportion of CHD patients aged≤18 years who underwent cardiovascular surgery also showed a downward trend, from 79.8% (61 557/77 120) in 2017 to 58.6% (41 871/71 492) in 2021 (P=0.027). The number of surgical cases varied greatly among different provinces, including 4 provinces with≥5 000 cases and 9 provinces with 2 000-5 000 cases. In the five years, the number of CHD cardiovascular surgeries in Central and East China was the largest, accounting for 41.1%-45.5% of the total surgical cases. The proportion of CHD surgery cases≤18 years old was the highest in Southwest China (69.7%-87.4%) and the lowest in Northeast China (28.2%-68.9%). Except for 2021, the number of cases carried out by each region between 2017 and 2020 was correlated with the gross regional product (r=0.929, 0.929, 0.893 and 0.964, respectively, all P<0.05) and the population (r=0.821, 0.893, 0.821 and 0.857, respectively, all P<0.05). Hospitals that performed more than 100 operations (20.5%±1.2% of the total number of hospitals) completed 86.2%±1.2% of the total number of operations in China during the 5-year period. In 2017 and 2021, the number of CHD cardiovascular surgeries preformed in children's/women's and children's specialized hospitals accounted for 24.3% (18 772/77 120) and 23.8% (17 012/71 492) of the total number of cases in China, respectively. Conclusions: From 2017 to 2021, the number of cardiovascular surgery for CHD decreases slightly, but the proportion of surgery for adult CHD patients increases significantly.There is a strong correlation between the number of CHD operations in each region and their economic development status. The scale of CHD cardiovascular surgery performed in children's hospitals/women's and children's hospitals accounts for about a quarter of the total volume in China.

[Efficacy analysis of chemotherapy and endocrine therapy combined with targeted drugs after progression on cyclin-dependent kinase 4/6 inhibitor treatment in hormone receptor positive/human epidermal growth factor receptor 2-low metastatic breast cancer]

Objective: To evaluate the efficacy of chemotherapy and endocrine therapy combined with targeted drugs after progression on cyclin-dependent kinase 4/6 (CDK4/6) inhibitor treatment in hormone receptor (HR) positive/human epidermal growth factor receptor 2 (HER2)-low metastatic breast cancer. Methods: Patients with metastatic breast cancer diagnosed with HR positive/HER2 low expression at the Fifth Medical Center of PLA General Hospital from October 1, 2018 to September 30, 2023 were retrospectively included. All patients received sequential chemotherapy or sequential endocrine therapy combined with targeted drugs after progression on CDK4/6 inhibitor treatment.The median follow-up was 9 months, and the follow-up ended on October 31, 2023. The patients were divided into chemotherapy group (receiving sequential chemotherapy) and endocrine therapy group (receiving sequential endocrine therapy combined with targeted drugs), according to the treatment plan. Information on demographic data, clinical and pathological diagnosis, treatment regimen, and efficacy evaluation was collected. The basic conditions of patients who may affect the curative effect of different treatment schemes were preset as stratified subgroups, including age, progesterone receptor (PR) status, HER2 status, disease-free survival, number of previous endocrine therapy and chemotherapy, and visceral metastasis. The primary endpoint was progression-free survival (PFS), the secondary endpoints were objective response rate (ORR), clinical benefit rate(CBR) and PFS based on stratification factors. The survival curve was plotted by Kaplan-Meier method, the comparison of PFS between groups was performed by log-rank test, and the comparison of ORR and CBR between groups were performed by χ2 test. Results: A total of 188 patients were included, including 126 patients in the chemotherapy group [all females, aged 29-74 (51±10) years] and 62 patients in the endocrine therapy group [1 male and 61 female, aged 29-77 (51±12) years]. ORR of chemotherapy group was 23.0% (29/126), higher than that of endocrine treatment group [3.2% (2/62)] (P<0.001); The CBR of chemotherapy group and endocrine therapy group were 46.8% (59/126) and 33.9% (21/62), respectively, with no statistical significance (P=0.091). The median PFS of chemotherapy group and endocrine therapy group were 5.0 (95%CI: 4.3-5.7) and 4.0 (95%CI: 1.6-6.4) months, respectively, with no statistical significance (P=0.484). In the preset stratified subgroups, the median PFS of chemotherapy [6.0 (95%CI: 5.4-6.6) months] was longer than that of endocrine combined with targeted therapy [2.0 (95%CI: 1.8-2.2) months] (P<0.001) in PR negative patients; In patients who had progressed on over 2 previous endocrine treatments, the median PFS of chemotherapy [5.0 (95%CI: 3.8-6.2) months] was longer than that of endocrine combined with targeted therapy [2.0 (95%CI: 0.6-3.4) months] (P=0.045). Conclusions: After progression on treatment with CDK4/6 inhibitors for HR-positive/HER2-low expression metastatic breast cancer, both chemotherapy and endocrine therpy combined with targeted drugs are viable treatment options. However, for patients with PR negative or ≥2 lines of endocrine therapy previously, priority should be accorded to chemotherapy.

Excitation functions for fast neutron induced reactions on iron and lead

Cross sections of the 54Fe(n,p)54Mn, 54Fe(n,α)51Cr, 56Fe(n,p)56Mn and 204Pb (n,2n)203Pb reactions induced by D-T neutrons were obtained with activation method and γ-ray spectrometry technique. Experimental values measured in this work are consistent with most of the previous literature data. These reactions cross sections were theoretically calculated by using the TALYS-1.96 and EMPIRE-3.2.3 codes from threshold up to 20 MeV, and significant discrepancies were found between calculated results and experiment data. In addition, experimental values are compared with evaluated nuclear data of the CENDL-3.2, ENDF/B-VIII.0, JENDL-5, BROND-3.1 and JEFF-3.3 libraries, and significant difference was found for the 54Fe(n,α)51Cr reaction in ENDF/B-VIII.0 library but not for other reactions.

[Efficacy analysis of 7 cases of mixed neuroendocrine-nonneuroendocrine neoplasm of the duodenal papilla]

The clinical data of 7 patients diagnosed with mixed neuroendocrine-nonneuroendocrine neoplasm were analyzed in the Department of Hepatobiliary Surgery of Hunan Provincial People's Hospital from January 2016 to December 2022. Among the 7 patients, 5 were male and 2 were female, with an average age of 59.3 years. Its clinical characteristics are similar to malignant ampulla tumors, and it is difficult to differentiate them. The preoperative puncture biopsy positivity rate is low, making it difficult to diagnose preoperatively, and the prognosis is worse.Comprehensive treatment including surgery, chemotherapy, and radiotherapy can be the preferred treatment option for this disease.

Predicting effect of anti-PD-1/PD-L1 inhibitors therapy for hepatocellular carcinoma by detecting plasma metabolite based on UHPLC-MS

Introduction

Anti-PD-1/PD-L1 inhibitors therapy has become a promising treatment for hepatocellular carcinoma (HCC), while the therapeutic efficacy varies significantly among effects for individual patients are significant difference. Unfortunately, specific predictive biomarkers indicating the degree of benefit for patients and thus guiding the selection of suitable candidates for immune therapy remain elusive.no specific predictive biomarkers are available indicating the degree of benefit for patients and thus screening the preferred population suitable for the immune therapy.

Methods

Ultra-high-pressure liquid chromatography-mass spectrometry (UHPLC-MS) considered is an important method for analyzing biological samples, since it has the advantages of high rapid, high sensitivity, and high specificity. Ultra-high-pressure liquid chromatography-mass spectrometry (UHPLC-MS) has emerged as a pivotal method for analyzing biological samples due to its inherent advantages of rapidity, sensitivity, and specificity. In this study, potential metabolite biomarkers that can predict the therapeutic effect of HCC patients receiving immune therapy were identified by UHPLC-MS.

Results

A partial least-squares discriminant analysis (PLS-DA) model was established using 14 glycerophospholipid metabolites mentioned above, and good prediction parameters (R2 = 0.823, Q2 = 0.615, prediction accuracy = 0.880 and p < 0.001) were obtained. The relative abundance of glycerophospholipid metabolite ions is closely related to the survival benefit of HCC patients who received immune therapy.

Discussion

This study reveals that glycerophospholipid metabolites play a crucial role in predicting the efficacy of immune therapy for HCC.

[Effect of HBV DNA load on the safety and prognosis of systematic therapy in advanced hepatocellular carcinoma]

Objective: To study the effect of hepatitis B virus (HBV) infection on the occurrence of liver damage, HBV reactivation (HBVr) and the influence of HBVr on the prognosis of patients with advanced hepatocellular carcinoma (HCC) receiving systemic therapy. Methods: The clinical data of 403 patients with HBV-related HCC at the Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-Sen University et al, from July 2018 to December 2020 were collected. The incidence of liver damage and HBVr during systematic therapy, and the influence of HBVr on survival prognosis were analyzed. Results: Of the 403 patients, 89.1% were male (n=359), with a median age of 51 years (51.5±12.1). Before propensity score matching (PSM), the proportion of patients with cirrhosis, TNM and advanced BCLC stage was higher in high HBV-DNA (baseline HBV-DNA>1000 U/ml, n=147) group comparing with the low HBV-DNA (baseline HBV DNA≤1000 u/ml, n=256) group (P<0.05). There was no significant difference in baseline indexes between the two groups after PSM. In 290 patients after PSM, there was no significant difference in the incidence of liver damage and HBVr between high HBV-DNA group and low HBV-DNA group (P>0.05). Survival analysis was performed on 169 patients with survival data, the median overall survival (OS) was found to be 11.49 months (95%CI: 7.77-12.89) and 16.65 months (95%CI: 10.54-21.99, P=0.008) in the high and low HBV-DNA groups, respectively. And median progression-free survival (PFS) was 7.41 months (95%CI: 5.06-8.67) and 10.55 months (95%CI: 6.72-13.54, P=0.038), respectively, with a statistically significant difference. There were no differences in overall survival (OS) and progression-free survival (PFS) between patients with and without HBVr and those with or without liver damage (P>0.05). Conclusions: HBV-DNA levels above 1 000 U/ml before systemic therapy do not increase the risk of liver damage or HBVr during systemic therapy in patients with HBV-related hepatocellular carcinoma, and such patients can safely receive systemic therapy.

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.

Study of High-Transverse-Momentum Higgs Boson Production in Association with a Vector Boson in the qqbb Final State with the ATLAS Detector

This Letter presents the first study of Higgs boson production in association with a vector boson (V=W or Z) in the fully hadronic qqbb final state using data recorded by the ATLAS detector at the LHC in proton-proton collisions at sqrt[s]=13  TeV and corresponding to an integrated luminosity of 137  fb^{-1}. The vector bosons and Higgs bosons are each reconstructed as large-radius jets and tagged using jet substructure techniques. Dedicated tagging algorithms exploiting b-tagging properties are used to identify jets consistent with Higgs bosons decaying into bb[over ¯]. Dominant backgrounds from multijet production are determined directly from the data, and a likelihood fit to the jet mass distribution of Higgs boson candidates is used to extract the number of signal events. The VH production cross section is measured inclusively and differentially in several ranges of Higgs boson transverse momentum: 250-450, 450-650, and greater than 650 GeV. The inclusive signal yield relative to the standard model expectation is observed to be μ=1.4_{-0.9}^{+1.0} and the corresponding cross section is 3.1±1.3(stat)_{-1.4}^{+1.8}(syst)  pb.

Healthcare-associated carbapenem-resistant Klebsiella pneumoniae infections are associated with higher mortality compared to carbapenem-susceptible K. pneumoniae infections in the intensive care unit: a retrospective cohort study

BACKGROUND

Klebsiella pneumoniae (KP) is an opportunistic pathogen causing severe pneumonia and sepsis. Carbapenem-resistant KP (CRKP) has become a major pathogen in many centres.

AIM

To investigate the association between carbapenem resistance and the mortality rate, length of stay, and hospital cost in patients with Klebsiella pneumoniae infection.

METHODS

The retrospective cohort study was conducted in the intensive care units of a large teaching tertiary hospital in southwest China between January 1st, 2020 and December 31st, 2022. To examine the impact of carbapenem resistance on mortality rates and economic burden, multivariate Cox regression and generalized linear models were constructed.

FINDINGS

The study included 282 adult patients with KP infection (135 CSKP; 147 CRKP). CRKP-infected patients demonstrated higher mortality risk (unadjusted hazard ratio (aHR): 1.980; 95% confidence interval (CI): 1.206-3.248; P = 0.007; aHR: 1.767; 95% CI: 1.038-3.005; P = 0.036) compared to CSKP-infected patients. Stratified analysis, according to type of KP infection, revealed that patients with healthcare-associated CRKP infection had a significantly higher mortality risk compared to those with CSKP infection (log-rank P = 0.015). Patients with CRKP infection had longer hospital stays than those infected with CSKP (adjusted mean: 38.74 vs 29.71 days; P = 0.003), and hospital-related expenses were notably higher among CRKP patients than CSKP patients (adjusted cost: £40,126.73 vs 25,713.74; P < 0.001).

CONCLUSION

CRKP infections increase mortality rates, prolong hospital stays, and raise healthcare costs. Healthcare facilities should adopt targeted strategies, including curtailing pre-infection hospitalization periods and managing medications more judiciously.

Measurement of the Centrality Dependence of the Dijet Yield in p+Pb Collisions at sqrt[s_{NN}]=8.16 TeV with the ATLAS Detector

ATLAS measured the centrality dependence of the dijet yield using 165  nb^{-1} of p+Pb data collected at sqrt[s_{NN}]=8.16  TeV in 2016. The event centrality, which reflects the p+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, R_{CP}, is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The R_{CP} shows a scaling with the Bjorken x of the parton originating from the proton, x_{p}, while no such trend is observed as a function of x_{Pb}. This analysis provides unique input to understanding the role of small proton spatial configurations in p+Pb collisions by covering parton momentum fractions from the valence region down to x_{p}∼10^{-3} and x_{Pb}∼4×10^{-4}.

A novel vitrified cryopreservation approach with stem cell-laden hydrogel microcapsules

BACKGROUND

Stem cell-laden hydrogel microcapsules construction is important for a wide application in tissue engineering and cell-based medicine, such as building an ideal immune barrier. Challenges are emerging for effectively storing such microcapsules by cryopreservation, and a large proportion of research has been on the cryopreservation of single cells encapsulated into microcapsules without a core-shell structure.

OBJECTIVE

To achieve the effective cryopreservation of stem cell-laden hydrogel microcapsules with a core-shell structure.

MATERIALS AND METHODS

A novel core-shell alginate hydrogel encapsulation method was used to produce mesenchymal stem cell-laden microcapsules by microfluidic technique.

RESULTS

This microcapsule could inhibit ice formation to achieve vitreous cryopreservation with a low concentration (2 M) of penetrating cryoprotectants.

CONCLUSION

Cell laden hydrogel microcapsules may have the potential to be the basis of a new strategy of cell cryopreservation and applications. https://doi.org/10.54680/fr24210110212.

Development and validation of a nomogram model for predicting distant metastasis of aged ≥50 patients with thyroid carcinoma: a SEER database analysis

OBJECTIVE

This work aimed to construct and validate a model for predicting distant metastasis (DM) in thyroid carcinoma (TC) patients aged≥50.

PATIENTS AND METHODS

The research data were collected from the Surveillance, Epidemiology, and End Results (SEER) program databases via SEER*Stat software (https://seer.cancer.gov/). Logistics regression was used to screen the independent risk factors for TC patients. The nomogram was constructed and validated based on the logistics regression results for predicting DM occurrence in TC patients. Moreover, the characteristic curves (ROC) were used to assess the predictive performance. The decision analysis curve (DCA) and the calibration curve were used to test this nomogram's accuracy and discrimination. Additionally, we analyzed survival and risk scores in TC patients with metastasis using the Kaplan-Meier (KM) method.

RESULTS

A total of 11,166 TC patients were divided into a training set and a validation set. The results showed that topography (T), lymph node metastasis (N), and (grade) G were crucial risk factors for predicting DM. ROC analysis showed that the model had a good discriminative ability both in the training and validation set. The DCA curve showed greater net benefits across a range of DM risks for the nomogram in the training and validation set. Survival analyses showed that the metastasis cases with low-risk scores have shown a poorer prognosis in this study, both in the training and validation set.

CONCLUSIONS

The nomogram model had excellent predictive performance and net benefit for predicting DM of TC patients aged ≥50. The model can help doctors develop treatment plans for their patients.

[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.

Search for New Phenomena in Two-Body Invariant Mass Distributions Using Unsupervised Machine Learning for Anomaly Detection at sqrt[s]=13 TeV with the ATLAS Detector

Searches for new resonances are performed using an unsupervised anomaly-detection technique. Events with at least one electron or muon are selected from 140  fb^{-1} of pp collisions at sqrt[s]=13  TeV recorded by ATLAS at the Large Hadron Collider. The approach involves training an autoencoder on data, and subsequently defining anomalous regions based on the reconstruction loss of the decoder. Studies focus on nine invariant mass spectra that contain pairs of objects consisting of one light jet or b jet and either one lepton (e,μ), photon, or second light jet or b jet in the anomalous regions. No significant deviations from the background hypotheses are observed. Limits on contributions from generic Gaussian signals with various widths of the resonance mass are obtained for nine invariant masses in the anomalous regions.

Toripalimab plus axitinib versus sunitinib as first-line treatment for advanced renal cell carcinoma: RENOTORCH, a randomized, open-label, phase III study

BACKGROUND

Immune checkpoint inhibitors in combination with tyrosine kinase inhibitors are standard treatments for advanced clear cell renal cell carcinoma (RCC). This phase III RENOTORCH study compared the efficacy and safety of toripalimab plus axitinib versus sunitinib for the first-line treatment of patients with intermediate-/poor-risk advanced RCC.

PATIENTS AND METHODS

Patients with intermediate-/poor-risk unresectable or metastatic RCC were randomized in a ratio of 1 : 1 to receive toripalimab (240 mg intravenously once every 3 weeks) plus axitinib (5 mg orally twice daily) or sunitinib [50 mg orally once daily for 4 weeks (6-week cycle) or 2 weeks (3-week cycle)]. The primary endpoint was progression-free survival (PFS) assessed by an independent review committee (IRC). The secondary endpoints were investigator-assessed PFS, overall response rate (ORR), overall survival (OS), and safety.

RESULTS

A total of 421 patients were randomized to receive toripalimab plus axitinib (n = 210) or sunitinib (n = 211). With a median follow-up of 14.6 months, toripalimab plus axitinib significantly reduced the risk of disease progression or death by 35% compared with sunitinib as assessed by an IRC [hazard ratio (HR) 0.65, 95% confidence interval (CI) 0.49-0.86; P = 0.0028]. The median PFS was 18.0 months in the toripalimab-axitinib group, whereas it was 9.8 months in the sunitinib group. The IRC-assessed ORR was significantly higher in the toripalimab-axitinib group compared with the sunitinib group (56.7% versus 30.8%; P < 0.0001). An OS trend favoring toripalimab plus axitinib was also observed (HR 0.61, 95% CI 0.40-0.92). Treatment-related grade ≥3 adverse events occurred in 61.5% of patients in the toripalimab-axitinib group and 58.6% of patients in the sunitinib group.

CONCLUSION

In patients with previously untreated intermediate-/poor-risk advanced RCC, toripalimab plus axitinib provided significantly longer PFS and higher ORR than sunitinib and had a manageable safety profile TRIAL REGISTRATION: ClinicalTrials.gov NCT04394975.

Fast neutron induced reaction cross sections on natural manganese and tantalum

The cross sections for the 55Mn(n,2n)54Mn, 181Ta(n,2n)180gTa, and 181Ta(n,p)181Hf reactions were measured to be 705.1 ± 26.1 mb at 14.0 MeV, 1362.7 ± 87.2 mb at 13.6 MeV, and 2.31 ± 0.09 mb at 13.6 MeV, respectively, by using an off-line γ-ray spectroscopic technique. The neutrons were produced via the 3H(d,n)4He reaction. The monitor reactions 27Al(n,α)24Na and 93Nb(n,2n)92mNb were used for neutron flux determination. The results from the present work were compared with those of the literature and the evaluated data from ENDF/B-VIII.0, JEFF-3.3, JENDL-5, CENDL-3.2, and BROND-3.1 libraries. Besides, the cross sections were also estimated with the TALYS-1.96 nuclear model code using different level density models for a better description of the present work and literature data. The present experimental results were found to be in good agreement with most of the available literature data and with the evaluated data.

[The cases of tracing the source of patients infected with Omicron variant of SARS-CoV-2 based on wastewater-based epidemiology in Shenzhen]

Wastewater-based epidemiology (WBE) is an emerging discipline, which has been applied to drug abuse tracking and infectious disease pathogen surveillance. During the COVID-19 epidemic, WBE has been applied to monitor the epidemic trend and SARS-CoV-2 variants etc. In order to detect hidden COVID-19 cases and prevent transmission in the community, wastewater surveillance system for monitoring SARS-CoV-2 RNA was developed in Shenzhen. The sewage sampling sites were set up in key places such as the port areas, urban villages and residential communities of Futian, Nanshan, Luohu and Yantian districts. From July 26 to November 30, 2022, a total of 369 sewage sampling sites were set up, covering 1.93 million people. Continuous sampling was carried out for 3 hours in the peak period of water use every day. Sewage virus enrichment and SARS-CoV-2 nucleic acid detection were carried out by polyethylene glycol precipitation method and RT-qPCR, and a positive water sample disposal process was molded. This article aims to introduce the case of source tracing of COVID-19 infected patients based on urban sewage in Shenzhen. The sewage monitoring of Honghu water treatment plant in Luohu District played an early warning role, and the source of infection was traced. In the disposal of positive water samples in Futian South Road, Futian District, the important experience of monitoring point layout was obtained. In the sewage monitoring of Nanshan village, Nanshan District, the existence of occult infection was revealed. Sharing the experience of tracing the source of COVID-19 patients to avoid the spread of COVID-19 in the community based on wastewater surveillance of SARS-CoV-2 RNA in Shenzhen, and summarizing the advantages and application prospects of sewage surveillance can provide new ideas for monitoring emerging or re-emerging pathogens that are known to exhibit gastrointestinal excretion in the future.

[Analysis of the clinical characteristics of acute myeloid leukemia related to the treatment of hematological and solid tumors]

Objective: To compare and analyze the clinical characteristics of acute myeloid leukemia (AML) related to the treatment of hematological tumors and solid tumors. Methods: The laboratory and clinical data of 41 patients with treatment-related AML (t-AML) in the Department of Hematology, Henan Cancer Hospital from January 2014 to December 2021 were retrospectively analyzed, and they were divided into hematological tumor group and solid tumor group. Survival analysis was performed using the Kaplan-Meier method and Log rank test. Results: The median interval from the first tumor diagnosis to t-AML in 41 patients was 21.0 (16.5-46.0) months; 24 (58.5%) had abnormal expression of lymphoid antigen, 28 (68.3%) had abnormal karyotype, 18 cases (43.9%) were positive for fusion gene, and 28 cases (68.3%) were positive for gene mutation; the median recurrence-free survival (RFS) was 11.0 months, and the median overall survival (OS) was 11.5 months. The proportion of acute promyelocytic leukemia ([APL], 0.0, 0/13), complete response ([CR],18.2%, 2/11), median OS (4.5 months) and median RFS (2.5 months) of t-AML patients in the hematological tumor group were significantly lower than those in the solid tumor group (35.7%, 10/28; 68.0%, 17/25; not reach; not reach), but the proportion of M4 /M5 (93.2%,12/13) was significantly higher than that in the solid tumor group (53.6%,15/18; all P values<0.05). Through subgroup analysis, the proportion of patients with positive PML-RARa and good prognosis karyotypes in the solid tumor group (35.7%, 10/28; 46.4%, 13/28) was significantly higher than that in the hematological tumor group (0.0, 0/13; 0.0, 0/13; P<0.05), while the proportion of patients with intermediate karyotypes (42.9%, 12/28) was significantly lower than that in the hematological tumor group (84.6%, 11/13; P<0.05), the difference was statistically significant. The CR rate (90.0%, 9/10), median OS (not reach) and median RFS (not reach) in the t-APL group were higher than those in the t-AML (without t-APL) group (38.5%, 10/26; 6 months; 8 months; P<0.05). After excluding the effect of t-APL patients, there was no significant difference in the CR rate, median OS and median RFS between the solid tumor group (8; 9 months; not reach) and the hematological tumor group (2; 4 months; 2 months; P>0.05). Univariate analysis showed that the primary tumor belongs to hematological tumor was a common risk factor for OS and RFS in t-AML patients (P<0.10). Conclusions: Compared with patients with t-AML secondary to solid tumors, patients with t-AML secondary to hematological tumors have poorer treatment effects and poorer prognosis. After excluding the effect of t-APL patients, there are no significant differences in the treatment efficacy and prognosis between the two types of t-AML patients.

Observation of WZγ Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WZγ production and a measurement of its cross section using 140.1±1.2  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The WZγ production cross section, with both the W and Z bosons decaying leptonically, pp→WZγ→ℓ^{'}^{±}νℓ^{+}ℓ^{-}γ (ℓ^{(^{'})}=e, μ), is measured in a fiducial phase-space region defined such that the leptons and the photon have high transverse momentum and the photon is isolated. The cross section is found to be 2.01±0.30(stat)±0.16(syst)  fb. The corresponding standard model predicted cross section calculated at next-to-leading order in perturbative quantum chromodynamics and at leading order in the electroweak coupling constant is 1.50±0.06  fb. The observed significance of the WZγ signal is 6.3σ, compared with an expected significance of 5.0σ.

Measurement and analysis of leakage neutron spectra from Lead slab samples with D-T neutrons

The leakage neutron spectra from three different sizes of Lead samples were measured by a TOF technique at 60° and 120°. The essential characteristic properties of the experimental measurement spectra can be reproduced well by MCNP code simulations with the ENDF/B-VIII.0, CENDL-3.2, JENDL-5.0, JEFF-3.3 and TENDL-2021 evaluated nuclear data libraries. The calculated results of JENDL-5.0 and JEFF-3.3 libraries agree better with the experimental data in the whole energy range. The results from ENDF/B-VIII.0 and CENDL-3.2 are overestimated in the 4-9 MeV range at 60° and in the 4-12.5 MeV range at 120°. The differences of the leakage neutron spectra by MCNP simulations using five evaluated nuclear data libraries mainly originate from the differences of the spectrum distributions of neutron reaction channels in these libraries. And the secondary neutron energy distribution and angular distribution from the five libraries have been present to explain it.

Direct Mass Measurements to Inform the Behavior of ^{128m}Sb in Nucleosynthetic Environments

Nuclear isomer effects are pivotal in understanding nuclear astrophysics, particularly in the rapid neutron-capture process where the population of metastable isomers can alter the radioactive decay paths of nuclei produced during astrophysical events. The β-decaying isomer ^{128m}Sb was identified as potentially impactful since the β-decay pathway along the A=128 isobar funnels into this state bypassing the ground state. We report the first direct mass measurements of the ^{128}Sb isomer and ground state using the Canadian Penning Trap mass spectrometer at Argonne National Laboratory. We find mass excesses of -84564.8(25)  keV and -84608.8(21)  keV, respectively, resulting in an excitation energy for the isomer of 43.9(33) keV. These results provide the first key nuclear data input for understanding the role of ^{128m}Sb in nucleosynthesis, and we show that it will influence the flow of the rapid neutron-capture process.

Combined Measurement of the Higgs Boson Mass from the H→γγ and H→ZZ^{*}→4ℓ Decay Channels with the ATLAS Detector Using sqrt[s]=7, 8, and 13 TeV pp Collision Data

A measurement of the mass of the Higgs boson combining the H→ZZ^{*}→4ℓ and H→γγ decay channels is presented. The result is based on 140  fb^{-1} of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.09(stat)±0.06(syst)=125.11±0.11  GeV. This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics.

Search for Dark Photons in Rare Z Boson Decays with the ATLAS Detector

A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon's coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α_{D}ϵ^{2}, in the dark photon mass range of [5, 40] GeV except for the ϒ mass window [8.8, 11.1] GeV. This search explores new parameter space not previously excluded by other experiments.

Clinical service evaluation of the feasibility and reproducibility of novel artificial intelligence based-echocardiographic quantification of global longitudinal strain and left ventricular ejection fraction in trastuzumab-treated patients

Introduction

Cardiotoxicity is a potential prognostically important complication of certain chemotherapeutic agents that may result in preclinical or overt clinical heart failure. In some cases, chemotherapy must be withheld when left ventricular (LV) systolic function becomes significantly impaired, to protect cardiac function at the expense of a change in the oncological treatment plan, leading to associated changes in oncological prognosis. Accordingly, patients receiving potentially cardiotoxic chemotherapy undergo routine surveillance before, during and following completion of therapy, usually with transthoracic echocardiography (TTE). Recent advancements in AI-based cardiac imaging reveal areas of promise but key challenges remain. There are ongoing questions as to whether the ability of AI to detect subtle changes in individual patients is at a level equivalent to manual analysis. This raises the question as to whether AI-based left ventricular strain analysis could provide a potential solution to left ventricular systolic function analysis in a manner equivocal to or superior to conventional assessment, in a real-world clinical service. AI based automated analyses may represent a potential solution for addressing the pressure of increasing echocardiographic demands within limited service-capacity healthcare systems, in addition to facilitating more accurate diagnoses.

Methods

This clinical service evaluation aims to establish whether AI-automated analysis compared to conventional methods (1) is a feasible method for assessing LV-GLS and LVEF, (2) yields moderate to good correlation between the two approaches, and (3) would lead to different clinical recommendations with serial surveillance in a real-world clinical population.

Results and Discussion

We observed a moderate correlation (r = 0.541) in GLS between AI automated assessment compared to conventional methods. The LVEF quantification between methods demonstrated a strong correlation (r = 0.895). AI-generated GLS and LVEF values compared reasonably well with conventional methods, demonstrating a similar temporal pattern throughout echocardiographic surveillance. The apical-three chamber view demonstrated the lowest correlation (r = 0.423) and revealed to be least successful for acquisition of GLS and LVEF. Compared to conventional methodology, AI-automated analysis has a significantly lower feasibility rate, demonstrating a success rate of 14% (GLS) and 51% (LVEF).

Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector

This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139  fb^{-1} of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688±23(stat) _{-71}^{+75}(syst)  fb, to be compared with the standard model prediction of 515_{-42}^{+36}  fb at next-to-leading order in QCD.

Measurement of Suppression of Large-Radius Jets and Its Dependence on Substructure in Pb+Pb Collisions at sqrt[s_{NN}]=5.02 TeV with the ATLAS Detector

This letter presents a measurement of the nuclear modification factor of large-radius jets in sqrt[s_{NN}]=5.02  TeV Pb+Pb collisions by the ATLAS experiment. The measurement is performed using 1.72  nb^{-1} and 257  pb^{-1} of Pb+Pb and pp data, respectively. The large-radius jets are reconstructed with the anti-k_{t} algorithm using a radius parameter of R=1.0, by reclustering anti-k_{t} R=0.2 jets, and are measured over the transverse momentum (p_{T}) kinematic range of 158 Collapse

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[Visual analysis of the current research status and hotspots of electric burns at home and abroad]

Objective: To analyze the literature on electric burns published at home and abroad, and to explore the research hotspots and frontiers of electric burns. Methods: The bibliometric method was used. The Chinese and English literature related to electric burns published in China National Knowledge Infrastructure, Wanfang database, VIP database and the core collection of Web of Science database from January 1, 2013 to December 31, 2022 were searched respectively, and the CiteSpace 6.2.R2 software was used for analysis. The number of papers, authors, countries, and institutions of Chinese and English literature were counted respectively, and the co-occurrence analysis of keywords and mutation analysis and cluster analysis on the basis of the co-occurrence analysis were conducted, besides, the clustering time line figure was obtained after the keywords were sorted by time to explore the current research status and the evolution process of hotspots in the field of electric burns. Results: A total of 398 English papers were retrieved from the core collection of Web of Science database, and a total of 523 Chinese papers were retrieved from China National Knowledge Infrastructure, Wanfang database, and VIP database after duplicate check. From 2013 to 2022, the number of English literature published in the field of electric burns showed a steadily upward trend, and the number of published Chinese literature showed a downward trend and tended to be stable. In Chinese literature, a total of 302 authors as the first author published papers related to electric burns, with 17 core authors published ≥3 papers; in English literature, a total of 320 authors as the first author published papers related to electric burns. Researches on electric burns were carried out in 65 countries, with United States having the most cooperation with other countries and the largest number of papers published. A total of 512 institutions at home and abroad published papers related to electric burns, and the institutions with the largest number of Chinese and English papers were Shanghai Electric Power Hospital in China (n=14) and Hallym University in Korea (n=11), respectively. A total of 1 176 Chinese keywords and 1 068 English keywords were included for co-occurrence analysis after excluding keywords related to the searching words. The top three keywords in frequency in Chinese literature were surgical flap, wound repair, and nursing, and the top three keywords in frequency in English literature were management, epidemiology, and children. Ten clusters were obtained by keyword analysis in Chinese literature, and the largest cluster was wound healing, followed by clinical effects and surgical flaps. Seven clusters were obtained by keyword analysis in English literature, and the largest cluster was reconstructive surgical procedures, followed by chronic pain and shock. The persistent clusters in Chinese literature were wound healing and clinical outcomes, etc., and the prominent nodes in the recent two years were surgical timing, limb electric burns, and hypertrophic scars; the persistent clusters in English literature were reconstructive surgical procedures and chronic pain, etc., and the prominent nodes in the recent two years were predictors and burn management, etc. In Chinese literature, the keyword with the longest duration of mutation (2017-2021) was wrist electric burns, and the keyword with the highest intensity of mutation was flap repair; in English literature, the keyword with the longest duration of the mutation (2019-2022) was voltage, and the keyword with the highest intensity of mutation was prevention. Conclusions: There are similarities and differences in the research directions and hotspots of electric burns at home and abroad. Surgical flap repair is a common research hotspot at home and abroad. At present, domestic research focuses on wound healing, wrist electric burns, and other aspects, while international research focuses on treatment management, epidemiology, reconstruction, and other aspects.

Measurement of the Sensitivity of Two-Particle Correlations in pp Collisions to the Presence of Hard Scatterings

A key open question in the study of multiparticle production in high-energy pp collisions is the relationship between the "ridge"-i.e., the observed azimuthal correlations between particles in the underlying event that extend over all rapidities-and hard or semihard scattering processes. In particular, it is not known whether jets or their soft fragments are correlated with particles in the underlying event. To address this question, two-particle correlations are measured in pp collisions at sqrt[s]=13  TeV using data collected by the ATLAS experiment at the LHC, with an integrated luminosity of 15.8  pb^{-1}, in two different configurations. In the first case, charged particles associated with jets are excluded from the correlation analysis, while in the second case, correlations are measured between particles within jets and charged particles from the underlying event. Second-order flow coefficients, v_{2}, are presented as a function of event multiplicity and transverse momentum. These measurements show that excluding particles associated with jets does not affect the measured correlations. Moreover, particles associated with jets do not exhibit any significant azimuthal correlations with the underlying event, ruling out hard processes contributing to the ridge.

Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector

A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[s]=13  TeV, corresponding to an integrated luminosity of 140  fb^{-1} recorded by the ATLAS experiment at LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds are estimated based on a hybrid approach involving Monte Carlo simulations and data-driven methods. Statistically significant excesses with respect to backgrounds dominated by the single parton scattering are seen in the di-J/ψ channel consistent with a narrow resonance at 6.9 GeV and a broader structure at lower mass. A statistically significant excess is also seen in the J/ψ+ψ(2S) channel. The fitted masses and decay widths of the structures are reported.

Observation of the γγ→ττ Process in Pb+Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS Detector

This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment a_{τ}. The dataset corresponds to an integrated luminosity of 1.44  nb^{-1} of LHC Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a τ-lepton decay, an electron or charged-particle track(s) from the other τ-lepton decay, little additional central-detector activity, and no forward neutrons. The γγ→ττ process is observed in Pb+Pb collisions with a significance exceeding 5 standard deviations and a signal strength of μ_{ττ}=1.03_{-0.05}^{+0.06} assuming the standard model value for a_{τ}. To measure a_{τ}, a template fit to the muon transverse-momentum distribution from τ-lepton candidates is performed, using a dimuon (γγ→μμ) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a_{τ} is -0.057 Collapse

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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.

[Topography-guided transepithelial corneal collagen cross-linking by sequential ultraviolet A irradiation in different diameters for progressive keratoconus in adults]

Objective: To compare the efficacy and safety of a novel customized topography-guided transepithelial corneal collagen cross-linking (TG-CXL) procedure by sequential ultraviolet A irradiation in different diameters and conventional transepithelial corneal collagen cross-linking (TE-CXL) in adult patients with progressive keratoconus. Methods: A prospective cohort study was conducted. Adult patients diagnosed with progressive keratoconus in the Affiliated Xiamen Eye Center of Xiamen University were continuously recruited and randomly assigned to receive the TG-CXL or TE-CXL procedure from March 2020 to March 2021. Patients in the TE-CXL group were irradiated in the central 9-mm zone of the cornea (total energy, 7.2 J/cm2; irradiance, 45 mW/cm2), while patients in the TG-CXL group were first irradiated with the protocol used in the TE-CXL group, and further irradiated in the central 6-mm zone (total energy, 3.6 J/cm2; irradiance, 9 mW/cm2). The subjective symptom of pain and corneal fluorescein sodium staining were scored within postoperative 3 days. Slit lamp examination, measurements of uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), corneal topography, anterior segment optical coherence tomography, in vivo corneal confocal microscopy, corneal endothelial cell count, and non-contact tonometry were performed before surgery and at 3, 6, and 12 months after surgery. Results: A total of 66 patients were enrolled (mean age, 23.0±3.3 years old), with 33 patients (33 eyes) in each group. No statistically significant differences were found in age, gender, and maximum keratometry (Kmax) between the two groups (P>0.05). On day 1 after surgery, the average pain score of the TG-CXL group (2.21±0.45) was significantly higher than that of the TE-CXL group (1.32±0.33) (P<0.05). The pain was rapidly alleviated in both groups on days 2 and 3. On days 1 and 2, the corneal fluorescein sodium staining scores in the TG-CXL group (4.15±0.83 and 2.21±0.60, respectively) were significantly higher than those in the TE-CXL group (1.76±0.56 and 0.85±0.51, respectively, P<0.001), while there was no significant difference between the two groups at day3 (P=0.184). The UCVA and BCVA of the TG-CXL group at 3, 6, and 12 months after surgery were significantly improved when compared with the baseline. At 3, 6, and 12 months, the BCVA (LogMAR) of the TG-CXL group (0.21±0.15, 0.22±0.16, and 0.22±0.16, respectively) were significantly improved when compared with those of the TE-CXL group(0.32±0.15, 0.34±0.15, and 0.36±0.16, respectively, P<0.01). However, there was no significant difference in UCVA between groups at any time point after surgery (P>0.05). The spherical and cylindrical power values of the TG-CXL group were improved when compared with the baseline (P<0.05). However, no significant difference in spherical power values was found between the two groups at any time point after surgery (P>0.05). Meanwhile, there were significant differences in cylindrical power values between the two groups at 6 and 12 months after surgery (P<0.05). The Kmax in the TG-CXL group was improved at all of the time points after surgery when compared with the baseline (P<0.001), while no significant difference in Kmax was found at any time point after surgery in the TE-CXL group when compared with the baseline (P>0.05). At 6 and 12 months after surgery, the Kmax values in the TG-CXL group were significantly lower than the TE-CXL group (P<0.05). No significant differences were found in flat keratomety, steep keratometry, the minimal thickness of the cornea, endothelial cell density, and intraocular pressure between the two groups at any time point after surgery (P>0.05). Within one month after surgery, optical coherence tomography revealed the increased density in the anterior stroma in both groups. In most patients in the TG-CXL group, a demarcation line was visible in the central and para-central corneal stroma, representing a clear and continuous, high-signal arc-shaped linear structure, which was deeper in the central cornea than the para-central cornea. In contrast, a demarcation line, fuzzy and focally discontinuous, was visible only in a few patients in the TE-CXL group, with an almost uniform depth in the central and the para-central cornea. Confocal microscopy demonstrated an apparent mesh-like cross-linked collagen structure in the superficial and intermediate corneal stroma at all time points after surgery in the TG-CXL group, with thickening stromal collagen fibers and an increased number of interconnections. In contrast, the mesh-like structure and number of interconnections in the superficial corneal stroma were significantly reduced at 12 months after surgery in the TE-CXL group, with no cross-linking structure in the intermediate corneal stroma at any time point after surgery. No serious complications such as corneal infection, sterile corneal ulcer, and persistent epithelial defect were observed in both groups during the follow-up of 12 months. Conclusions: The TG-CXL procedure by sequential irradiation in two different diameters with ultraviolet A light was effective and safe in the management of progressive keratoconus in adults, achieving significant refractive improvement. This might be a good technical alternative for refractive corneal cross-linking surgery.

Dosimetric Advantages of Online Adaptative Radiotherapy for Cervical Cancer on 1.5T MR-Linac

PURPOSE/OBJECTIVE(S)

Online adaptative radiotherapy (ART) strategy can be applied to account for inter-fraction organ motion while limiting organ at risk (OAR) dose. This study aims to evaluate tumor target and OARs inter- and intrafraction motion using online MRI during the full course of MR-Linac radiotherapy fractions. Furthermore, quantify the dosimetric consequences of online adaptative compared with non-adaptative radiotherapy (non-ART) in cervical cancer.

MATERIALS/METHODS

Six cervix cancer patients were treated with 150 fractions on the 1.5 T Unity MR-Linac. Each fraction, pre-treatment MRI scans were obtained at the start of every treatment session, and post-treatment MRI scans were obtained at the end of every treatment session. A total 300 MR images were included in this study and the CTV, bladder and rectum were delineated on each MRI by the same radiation oncologist. The inter-fraction and intrafraction changes of contours were evaluated by dice similarity coefficient (DSC), Hausdorff distance (HD), volume difference (ΔV). The reference treatment plans were generated using step-and-shoot IMRT and utilized 9 beam groups on original CT. Then, the online adaptative treatment plans were obtained by re-optimizing based on the contours on daily pre-treatment MRI by "adapt to shape" workflow using the same beam parameters and optimization objectives from the reference plans. Non-ART plans for each patient were generated by recalculating the dose from the reference plans on daily online MRI by "adapt to position" workflow. CTV coverage and OARs constraints were used to compare ART and non-ART plans.

RESULTS

The results showed that large inter-fraction anatomical changes limited the efficacy of radiation therapy (CTV: DSC: 0.89±0.03, HD: 20.83±5.05mm, ΔV: 1.21%±5.44%; Bladder: DSC: 0.68±0.18, HD: 30.58±15.75mm, ΔV: -10.17%±61.19%; Rectum: DSC: 0.69±0.09, HD: 22.98±12.03mm, ΔV: 21.01%±20.59%).The intrafraction anatomical changes were smaller (CTV: DSC: 0.96±0.01, HD: 8.85±3.54mm, ΔV: -0.64%±1.90%; Bladder: DSC: 0.90±0.07, HD: 14.62±9.56mm, ΔV: 19.83%±21.71%; Rectum: DSC: 0.98±0.04, HD: 2.90±4.27mm, ΔV: 0.13%±5.04%) . Non-ART showed inadequate primary CTV coverage in 30% of the daily fractions. Online adaptative plans improved CTV coverage significantly (p<0.001) to 99%. Compared with non-ART, online ART decreased the fraction dose to bladder and rectum indicated by significant (p<0.001) improvements for daily D50%, D2% and Dmean.

CONCLUSION

In cervical cancer radiotherapy, a non-adaptive strategy led to inadequate target coverage for individual patients. Online adaptative radiotherapy corrected for day-to-day anatomical variations and resulted in adequate target coverage in all fractions. The dose to rectum and bladder was decreased significantly when applying online adaptative radiotherapy.

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

PURPOSE/OBJECTIVE(S)

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

MATERIALS/METHODS

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

RESULTS

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

CONCLUSION

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

Radiation Therapy Sensitizes Head-and-Neck Cancer Cells to Killing by Chimeric Antigen Receptor (CAR)-NK Cells Targeting CD70

PURPOSE/OBJECTIVE(S)

CAR-T cell therapy is limited by toxicity, high cost, logistical manufacturing issues in the autologous setting and risk of GVHD in the allogeneic setting. Substitution of T cells with NK cells opens the possibility for an allogeneic off-the-shelf product with a better safety profile. However, the inadequate efficacy of CAR-NK cells against solid tumors can be extrapolated from experience with CAR-T cells. There is limited but promising preclinical evidence that radiation therapy (RT) enhances CAR-T cell tumoricidal activity against solid tumors. However, there is no data examining the potential synergy between RT and CAR-NK cell therapy.

MATERIALS/METHODS

We engineered CAR-NK cells with CD27 receptor as extracellular domain to target its natural ligand CD70, which is overexpressed in head-and-neck cancers (HNSCC). CAR-NK cell killing was assessed real-time through xCELLigence cytotoxicity assays. CD70+ OQ01 human HNSCCs were used for most experiments. FaDu is a CD70- HNSCC (negative ctrl). UMRC3 is a CD70+ kidney cancer cell line (positive ctrl). CD70 expression pre- and post-RT was assessed by flow cytometry and Western blot. Ionizing RT was compared at 5 doses: 0, 1.75, 3.5, 7, and 14 Gy. A single dose of 3.5 Gy was used for most experiments. Post-radiation effects were generally assessed at 3 days or 9 days post-RT. Intracellular staining was used to assess NK cell expression of IFN-γ, CD107a, and TNF-α by flow cytometry. CD27/CD70 interaction blockade was through α-CD27 pre-treatment of CAR-NK cells.

RESULTS

OQ01 HNSCCs heterogeneously express CD70 and are killed by CD70 CAR-NK cells in vitro. Pre-conditioning low-dose RT of 3.5 Gy applied to OQ01 HNSCCs 3 days prior to coculture with NK cells enhances CD70 CAR-NK cell killing, with ∼30% increased cytotoxicity against the tumor cells. Low-dose RT by itself did not induce acute cytolysis. As a possible mechanism for the increased sensitivity of irradiated OQ01 cells to CD70 CAR-NK cells, we found that RT enhances CD70 expression among HNSCCs in a dose-dependent manner. There was no increase in NK cell expression of IFN-γ, CD107a, and TNF-α with exposure to irradiated target cells. CD27/CD70 blockade does not solely abrogate RT-induced sensitization toward CAR-NK cell killing. Despite RT induction of transient increased expression of CD70, which normalizes by 9 days post-RT, there is persistent increase in RT-synergized target cell killing even at this later timepoint. Thus, altogether, RT sensitizes CD70-expressing HNSCC cells to CAR-NK cell killing in vitro.

CONCLUSION

This work represents the first preclinical study to identify the synergy of RT and CAR-NK cell therapy in solid tumors and is the first demonstration of CAR-NK cell activity against human HNSCCs. We show significantly enhanced potency of CAR-NK cells against irradiated tumor cells in vitro. Collectively, this research will be vital to guide efforts expanding into other target antigens and tumor types.

Effect of Anemia on Tumor Response to Preoperative Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

PURPOSE/OBJECTIVE(S)

Preoperative neoadjuvant chemoradiotherapy (nCRT) and total rectal mesenteric resection (TME) are the primary treatment options for locally advanced rectal cancer (LARC), but their efficacy varies. This study aimed to investigate the impact of anemia on the tumor response of patients with LARC receiving preoperative neoadjuvant chemoradiotherapy.

MATERIALS/METHODS

This study was a retrospective analysis of clinical and pathological data from patients with LARC who underwent nCRT and TME from January 2019 to May 2022 at a single institution. The tumor response was evaluated based on the tumor regression grade (TRG) and T-stage change of the primary tumor. Hemoglobin concentration was measured and graded to determine the presence of anemia. Anemia was categorized into four groups based on the hemoglobin levels: mild anemia (90-120 g/L), moderate anemia (60-90 g/L), severe anemia (30-60 g/L), and extreme anemia (less than 30 g/L). Finally, tumor response was quantified histologically using the AJCC 8th edition tumor regression grading system for rectal cancer and pre- and post-treatment T-grading.

RESULTS

A total of 88 patients with LARC who received nCRT and TME were included in the study, with 17 females and 71 males. Of these patients, 9 were moderately anemic and 37 were mildly anemic. The radiation therapy regimen was administered at a dose of 1.8-2 Gy per fraction, five times a week, for a total dose of 45-50.4 Gy. Capecitabine chemotherapy was also administered orally (825 mg/m2, twice a day) on the days of radiation therapy. Other chemotherapy regimens included XELOX and mFOLFOX6. The TRG was significantly different in anemic patients compared to non-anemic patients (P = 0.039). Only 2 out of 46 anemic patients (4%) showed an excellent response (TRG0), while 8 out of 42 non-anemic patients (19%) showed an excellent response (p = 0.043). There was also a significant difference in the incidence of anemia between cT3 and cT4 stages (p = 0.048), with 44% of cT3 patients and 67% of cT4 patients being anemic. The number of patients with poor response (TRG2-3) decreased as the degree of anemia decreased, but no significant difference was found. The incidence of TRG3 was 11% in patients with moderate anemia and 7% in non-anemic patients (P = 0.863). There was no significant difference in postoperative pathological T-stage between anemic and non-anemic patients. 89% of anemic patients had a pathological stage of ypT3 or less after chemoradiotherapy, while 95% of non-anemic patients did (P = 0.167). The pre- and post-treatment pathological staging did not significantly differ between anemic and non-anemic patients. 67% of anemic patients had descending tumors, while 59.5% of non-anemic patients had descending tumors (p = 0.509).

CONCLUSION

Patients with LARC who have normal hemoglobin concentrations during nCRT have better tumor regression compared to patients with anemia. Additionally, the incidence of anemia was higher among patients with advanced T-stage prior to treatment.

Inter-fractional Assessment during MR-guided Online Adaptive Radiotherapy for Glioblastoma

PURPOSE/OBJECTIVE(S)

Magnetic resonance image (MRI) guided radiation therapy has the potential to improve outcomes for glioblastoma by adapting to tumor changes during radiation therapy. This study aimed to assess the feasibility and potential benefits of MR-guided online adaptive radiotherapy (MRgOART) for patients with glioblastoma.

MATERIALS/METHODS

Twenty consecutive patients with glioblastoma were treated with MRgOART of 60 Gy in 30 fractions by the 1.5 T MR-Linac. The MRgOART fractions employed daily MR scans and the contours were utilized to create each adapted plan. The gross tumor volume (GTV) and clinical target volume (CTV) were delineated on MRI of pre-treatment simulation (Fx0) and all fractions (Fx1, Fx2, Fx3 ... Fx30) to evaluate the inter-fractional changes. These changes were quantified using absolute/relative volume (∆V), Dice similarity coefficient (DSC) and Hausdorff distance (HD) metrics. The reference treatment plans were generated using step-and-shoot IMRT and utilized 7-9 beam groups on original CT. Before the treatment, a synthetic CT (sCT) quality assurance (QA) process was performed to assess the dose accuracy of bulk relative electron density (rED) assignment for online MRI based treatment plan in terms of gamma analysis, point dose comparison and dose volume histogram (DVH) parameters. Then, the online adaptative treatment plans were obtained by re-optimizing based on the contours on daily pre-treatment MRI by "adapt to shape" workflow. Non-adaptive plans for each patient were generated by recalculating the dose from the reference plans on daily online MRI by "adapt to position" workflow. GTV and CTV coverage and organ at risk (OAR) constraints were used to compare non-adaptive and adaptive plans.

RESULTS

For both criteria, the 1%/1mm (98.58%±0.15%) and 2%/2mm (99.88%±0.18%) gamma passing rate results were always clinically acceptable in sCT QA process. The differences on point dose and DVH parameters between the plans based on sCT and original CT were less than 1%. A total of 20 patients with 600 fractions were evaluated. The results showed that large inter-fractional changes for GTV limited the efficacy of radiation therapy (DSC: 0.78±0.08, HD: 20.94±3.64mm, ∆V: 2.92%±6.36%). The inter-fractional CTV changes were smaller (DSC: 0.91±0.04, HD: 15.31±3.09mm, ∆V: 1.41%±1.29%). GTV coverage of non-adaptive plans was below the prescribed coverage in 228/600 fractions (38%), with 90 (15%) failing by more than 10%. For CTV coverage of non-adaptive plans, the changes were less than 5%. Online adaptative plans improved GTV and CTV coverage significantly (p<0.001) to 99%. The adaptive plans also had lower dose to whole brain than non-adaptive plans (p<0.001).

CONCLUSION

Significant inter-fractional tumor changes could be found during radiotherapy in patients with glioblastoma treated by the 1.5 T MR-Linac. Daily MR-guided re-optimization of treatment plans corrected for day-to-day anatomical variations and resulted in adequate target coverage in all fractions.

Adaptive Auto-Segmentation for MRI-Guided Online Adaptive Radiotherapy of Cervical Carcinoma

PURPOSE/OBJECTIVE(S)

Accurate and efficient delineation of organs and targets on session images is critical in MRI-guided online adaptive radiotherapy (MRgOART). This study proposes a registration-guided deep learning image segmentation framework to assist online delineation of cervical carcinoma.

MATERIALS/METHODS

A total of 300 T2-weighted MR images were acquired for patients with cervical carcinoma treated by a 1.5T Unity MR-Linac. The CTV, bladder, rectum, pelvic bone and femoral joints were delineated on each MRI by the same radiation oncologist. To overcome these obstacles to online MRI segmentation, we propose a registration-guided DL (RgDL) segmentation framework that integrates image registration algorithms and DL segmentation models. Firstly, the DL segmentation model was trained using nnU-net. Then, for each treatment fraction, the deformable image registration (DIR) algorithm generates initial contours from previous treatment fraction, which were used as guidance by DL model to obtain the accurate current segmentation. The segmentation accuracy of alone DIR, DL and RgDL were evaluated by dice similarity coefficients (DSC) and other distance-based metrics.

RESULTS

Compared to the baseline approaches using the DIR and the DL alone, RgDL achieved a DSC of 91.12% on CTV, higher than DIR and DL alone by 15.54% and 10.13%. The DSC of RgDL were improved to 95.58%, 93.65%, 87.8% and 94.84% for bladder, pelvic bone, rectum and femoral joints, higher than DIR and DL alone by 9.61% on average.

CONCLUSION

The proposed adaptive auto-segmentation method can achieve accurate and efficient segmentation and potentially overcome these obstacles to MRgOART.

Influence of Eyes Movement on Lens Dose during MR-Guided Radiotherapy for Brain Tumor

PURPOSE/OBJECTIVE(S)

Modern radiotherapy techniques achieve highly conformal target doses while avoiding organs at risk such as lens. The magnitude of eyes movement and its influence on lens dose is unclear. The lens dose is relevant for cataract formation. This study aims to evaluate the movement-range of lens and its influence on dose distribution during MR-guided radiotherapy for brain cancer patients.

MATERIALS/METHODS

Fifty patients with brain cancer who were treated with MR-guided radiotherapy on 1.5 T MR-Linac were included in this study. All patients underwent a pre-treatment MRI and post-treatment MRI for each fraction. The eyes and lens were delineated on each MR image by a radiation oncologist. The reference treatment plans based original CT were recalculated on each MRI by "adapt to position" workflow. Then, we created planning risk volume (PRV) for lens by adding population margin and reoptimized the reference plans to evaluate the dose changes for lens. Inter-fraction and intrafraction variability for eyes and lens were evaluated with the Dice similarity coefficient (DSC), the Hausdorff distance (HD) and mean distance to agreement (MDA). Differences in daily dose (Dmax and Dmean) for eyes and lens were assessed.

RESULTS

A total of 300 MR images were analyzed in this study. The eyes motion was observed (minimum DSC: 0.57; maximum HD: 10.53; maximum MDA: 3.13). And the obvious lens motion also was found (minimum DSC: 0.01; maximum HD: 10.78; maximum MDA: 5.68). The maximum dose changes for eyes were up to 34.1% and the mean dose changes were up to 18.1%. The maximum dose changes for lens were up to 97.9% and the mean dose changes for eyes were up to 89%. When the reoptimized plans were generated by PRV lens, the dose changes were decreased nearly to 0.

CONCLUSION

Eyes movements in all radiotherapy fractions result in higher lens doses and potentially increase cataract formation rate. Adding margin expansions in treatment planning, to account for eyes motion, is the feasible approach to limit lens dose.

Pilot Study of a Novel Ring Gantry-Based PET/CT Linear Accelerator in Patients with Prostate Cancer Receiving [18F]-DCFPyL for PSMA PET Imaging

PURPOSE/OBJECTIVE(S)

The RefleXion X1® system is a hybrid PET imaging-radiotherapy system that uses real-time positron emissions from a PET tracer to deliver biologically guided radiotherapy (BgRT). This study (NCT05470699) evaluated the hypothesis that the X1 PET imaging subsystem would be able to detect [18F]-DCFPyL PSMA PET signal sufficient to generate a deliverable BgRT plan in patients with prostate cancer.

MATERIALS/METHODS

Patients with prostate cancer scheduled for a diagnostic [18F]-DCFPyL PSMA PET scan as part of standard of care were eligible. Upon completion of the diagnostic PSMA PET scan, images were transferred to the radiotherapy planning system for target identification and contouring. If at least one PET avid tumor lesion was identified, the patient was then scanned on the X1 unit. BgRT planning was performed on each X1 scanned patient. The target lesion volume, activity concentration (AC) and normalized target signal (NTS) were acquired. Successful and deliverable BgRT plans required that the target AC was ≥ 5 kBq/ml and NTS ≥ 2.7.

RESULTS

Twenty-six patients underwent [18F]-DCFPyL PET scans (13 with rising PSA after surgery or radiotherapy, 6 with known metastases and 7 with newly diagnosed high-risk prostate cancer). Median (range) PSA was 3.40 (0.04-122). In 16 patients a PET avid tumor was identified and contoured for planning (4 lymph nodes, 5 bone, 6 prostate gland, and 1 prostate bed). In 13 patients the target lesion was visualized on the X1 PET scan, while in 3 patients the target lesion was too close to the bladder to be clearly visualized. BgRT planning was feasible and met standard of care published SBRT organ dose constraints in 8 patients (3 prostate gland, 3 bone, 2 lymph nodes). BgRT planning was not feasible in 8 patients due to insufficient AC, low NTS or proximity of the target lesion to the PET avid bladder. The accompanying table compares median (range) target volume, AC and NTS for feasible versus not feasible plans.

CONCLUSION

This is the first study to investigate the feasibility of using [18F]-DCFPyL PET imaging for BgRT plan generation on the X1 system in patients with prostate cancer. Lesions that are relevant to radiotherapy of prostate cancer can be visualized including lymph node and bone metastases. A dedicated BgRT workflow with PSMA PET imaging on the X1 at 60 minutes post injection will result in higher target AC and will optimize BgRT planning. PET avid lesions < 1 cm or close to the bladder may make BgRT planning challenging. [18F]-DCFPyL-guided BgRT is technically feasible using the RefleXion X1. BgRT using targeted PET radiopharmaceuticals to biologically guide external beam radiotherapy represents a promising new dimension in radiation oncology and warrants further investigation.

Linking the Mechanics of Chewing to Biology of the Junctional Epithelium

The capacity of a tissue to continuously alter its phenotype lies at the heart of how an animal is able to quickly adapt to changes in environmental stimuli. Within tissues, differentiated cells are rigid and play a limited role in adapting to new environments; however, differentiated cells are replenished by stem cells that are defined by their phenotypic plasticity. Here we demonstrate that a Wnt-responsive stem cell niche in the junctional epithelium is responsible for the capability of this tissue to quickly adapt to changes in the physical consistency of a diet. Mechanical input from chewing is required to both establish and maintain this niche. Since the junctional epithelium directly attaches to the tooth surface via hemidesmosomes, a soft diet requires minimal mastication, and consequently, lower distortional strains are produced in the tissue. This reduced strain state is accompanied by reduced mitotic activity in both stem cells and their progeny, leading to tissue atrophy. The atrophied junctional epithelium exhibits suboptimal barrier functions, allowing the ingression of bacteria into the underlying connective tissues, which in turn trigger inflammation and mild alveolar bone loss. These data link the mechanics of chewing to the biology of tooth-supporting tissues, revealing how a stem cell niche is responsible for the remarkable adaptability of the junctional epithelium to different diets.

Dosimetric Plan Evaluation of Biology Guided Radiotherapy Using [18F]-DCFPyL PSMA Radiotracer in Patients with Prostate Cancer

PURPOSE/OBJECTIVE(S)

The X1 system represents a cutting-edge solution in radiotherapy delivery, with its capability to perform Biology Guided Radiotherapy (BgRT). The system utilizes real-time positron emission tomography (PET) signal as biological fiducials to provide tracked dose delivery and is initially available for use with [18F]-Fluorodeoxyglucose (FDG). The aim of this research study is to assess the quality of BgRT treatment plans for prostate cancer using patients' PSMA PET images obtained on the X1 system.

MATERIALS/METHODS

Sixteen patients with at least one PET-avid tumor identified on their whole-body diagnostic PSMA PET scan were selected. These patients were scanned on X1 following their diagnostic scan without additional radiotracer administration. Based on the X1 PET images, a BgRT plan was created for each patient, with the prescription dose determined by the location of treatment sites. The planning objectives of organs-at-risk (OARs) were established in accordance with the 2018 Timmerman guidelines. Target coverage objective was the dose covering 95% (D95%) of the planning target volume (PTV) to be higher than 100%. The following parameters were analyzed: PTV D95%, the minimal dose (Dmin) of gross tumor volume (GTV), plan maximum dose (Dmax), conformity index (CI), gradient index (GI), and maximum point dose (D0.03cc) to the nearest OARs. The X1 BgRT planning system also generated dose volume histogram (DVH) bounds, which model variations in BgRT delivery. The low boundary of GTV Dmin, representing the minimum GTV dose in the worst-case scenario, was recorded.

RESULTS

BgRT plans were created for all patients, except for one where the target signal was indistinguishable from the bladder. The prescription dose was 2700 cGy or 3000 cGy in 3 fractions for lymph node lesions, 2400 cGy to 3000 cGy in 3 fractions for bone metastasis, and 4500 cGy in 5 fractions for lesions in prostate. All plans met the dose constraints for OARs as per the Timmerman guidelines. The Dmax of all plans was 129.9% ± 6.9% (mean ± standard deviation). The PTV D95% and GTV Dmin were 101.7% ± 1.0% and 111.0% ± 7.6%, respectively. The low boundary of GTV Dmin was 95.9% ± 5.8%. The CI and GI were 1.22 ± 0.11 and 9.40 ± 2.12, respectively. The D0.03cc to nearest OARs was 84.6% ± 25.4%. The estimated treatment time was 699 ± 228 seconds.

CONCLUSION

This study is a pioneering effort to evaluate the quality of BgRT plans for prostate cancer patients using the [18F]-DCFPyL PSMA radiotracer. Our results showed that all BgRT plans met the planning objectives defined in the Timmerman protocol. BgRT with [18F]-DCFPyL represents a promising treatment modality for patients with prostate cancer. Further research is needed to validate this approach, including a comprehensive assessment of the dosimetric and tracking accuracy through physical measurements.

Radiotherapy Combined with PD-L1 Antibody Exerts a Synergistic Anti-tumor Effect in a Mouse Model of Esophageal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

The combination of radiotherapy and immune checkpoint inhibitors (ICIs) has been shown to exert synergistic anti-tumor effects in various tumors. In esophageal squamous cell carcinoma (ESCC), several clinical trials of radiotherapy combined with ICIs are undergoing or have been finished. However, the efficacy and action mechanisms of radiotherapy combined with ICIs is still not clear in ESCC. Our study aimed to investigate whether radiotherapy improved the anti-cancer effect of PD-L1 antibody and the effect of this combination therapy on tumor-immune microenvironment.

MATERIALS/METHODS

The mouse esophageal cancer cell line mEC25 was implanted into the armpits of female C57 mice. When the tumor volume grew to 150-250 mm3, the mice were randomly divided into different groups including control group (administration of IgG antibody), radiotherapy group (12 Gy at 4 Gy per fraction), PD-L1 antibody group (200 mg/kg i.p. for three times) and combination group (fractionated radiation combined with PD-L1 antibody was delivered on day 1, day 4 and day 7, the day when fractionated radiation began was recorded as day 1).The mice were sacrificed on the 1st, 3rd and 7th day after the treatment was ended. The tumor, spleen and draining lymph nodes of the mice were collected and analyzed using flow cytometry (FCM), and the tumor volume and survival time of mice were calculated.

RESULTS

Compared with radiotherapy or PD-L1 antibody alone, the combination therapy significantly prolonged the survival time of mice and decreased the growth rate of xenograft tumors FCM analysis showed that the combination therapy significantly increased the infiltration and cytotoxicity of effector T cells and reduced the proportion of M2 macrophages in tumor, spleen and lymph nodes. In addition, in tumor and spleen, the proportion of regulatory T cells (Tregs) decreased in the group of combination therapy. In tumor, spleen, and lymph nodes, the proportion of central memory T cell (TCM) was increased in the group of combination therapy.

CONCLUSION

The anti-tumor effect of radiotherapy combined with PD-L1 antibody is superior to single treatment in the mouse model of esophageal cancer. Radiotherapy can shape tumor-immune microenvironment, allowing the infiltration of effector T cells and exclusion of immune-suppressive cells such as M2 macrophages and Tregs.

Comparison of AI-Based Auto-Segmentation Quality with Different Daily IGRT Imaging Modalities for Adaptive Radiotherapy Treatment Planning

PURPOSE/OBJECTIVE(S)

Modern AI-based auto-segmentation tools may be applied on daily computed tomography (CT) images in an image-guided radiotherapy course to facilitate evaluation of anatomical variations and adaptive treatment planning. However, most AI auto-segmentation models are trained with high-quality diagnostic or planning CT image data. This study aims to evaluate and compare auto-segmentation quality by an AI-based auto-segmentation system with different daily CT imaging modalities.

MATERIALS/METHODS

We retrospectively retrieved daily IGRT images for sixty patients. Among them, twenty patients were treated on helical tomotherapy with daily megavoltage CT (MVCT) scans, twenty patients were treated on conventional Linacs with daily cone-beam CT (CBCT) scans, and twenty patients were treated on a biology-guided radiotherapy (BgRT)-capable machine with daily fan-beam kilovoltage CT (kVCT) scans. With each treatment modality, ten patients received daily CT scans in the pelvic region while the other ten received daily CT scans in the thoracic region. An auto-segmentation system using a convolutional neural network algorithm was trained in-house with historical treatment planning CT and contouring data to generate auto-segmentation models for the pelvic and thoracic regions, respectively. Normal organs were first delineated the auto-segmentation system on the daily CT images and then drawn by an experienced planner. A set of metrics including the dice similarity coefficient (DSC), Jaccard similarity index, and Hausdorff distance were used to evaluate the quality of the auto segmentation results compared with manual contours.

RESULTS

The auto-segmentation contours on the kVCT images showed higher average DSC compared to those on the MVCT and CBCT images for all the major organs in both the pelvic and thoracic regions including the bladder, rectum, bowel, left and right femurs, esophagus, heart, left and right lung, and spinal cord. With the kVCT images, the average DSC ranged from 0.52±0.22 to 0.996±0.005. In the pelvic region, the largest absolute difference in DSC was observed for the bowel volume with an average DSC of 0.69±0.16, 0.49±0.27, and 0.32±0.25 for the kVCT, MVCT, and CBCT images, respectively (p-value < 0.05 with unpaired t-tests between kVCT and the other two imaging modalities); in the thoracic region, the largest absolute difference in DSC was observed for the esophagus with an average DSC of 0.63±0.16, 0.22±0.08, and 0.15±0.18 for the kVCT, MVCT, and CBCT images, respectively (p-value < 0.05 with unpaired t-tests between kVCT and the other two imaging modalities). Similar results were observed with other metrics.

CONCLUSION

The AI-based auto segmentation system showed improved agreement with manual contouring when using kVCT images from the BgRT capable machine compared to MVCT or CBCT images. However, manual correction is necessary on auto-segmentation results from all imaging modalities especially for organs with limited contrast from surrounding tissues.

The Role of Esophagography in the Diagnosis of Orthotopic Esophageal Squamous Cell Carcinoma in a Mouse Mode

PURPOSE/OBJECTIVE(S)

Animal models play an irreplaceable role in pre-clinical studies of various tumors, mainly including xenogeneic/homograft subcutaneous tumor models. However, the subcutaneous transplanted tumor model is separated from the microenvironment of the primary tissue and fail to accurately simulate the growth of tumor cells in vivo. Therefore, orthotopic tumor models play an increasingly important role. For esophageal squamous cell carcinoma, chemotherapy-induced methods have successfully established mouse models of esophageal squamous cell carcinoma, but past experiments have found that it is still a challenge to confirm the success of the mouse model of esophageal cancer. The pathological diagnosis of the esophageal cancer tissue obtained from the killed mouse model remains the gold standard, but it also represents a lost opportunity to evaluate the efficacy of subsequent treatment. Notedly, esophagography is the primary examination for clinical patients with esophageal cancer. Therefore, the aim of this study is to evaluate whether esophagography can be used to establish a successful in situ mouse model of esophageal cancer.

MATERIALS/METHODS

Referring to previous literature, we used the chemical drug 4-Nitroquinoline N-oxide (4-NQO) to induce orthotopic tumor model: A certain amount of 4-NQO was dissolved in propylene glycol to make a 2% stock solution, and then dissolved in 200ml of sterile water for the daily drinking water of mice. The water was kept in the dark and replaced once a week. After 16 weeks of induction, the drinking water was replaced by the same volume of sterile water and continued to be fed for 12 weeks. The mice were subsequently subjected to esophagography: First, the mice were fixed on a plastic plate, and the gavage needle was slowly inserted into the stomach, then slowly withdrawn out and gradually injected with meglumine diphosphate, with a total amount of 0.1-0.2ml. Then the radiolucent film was taken immediately, and three positions were selected, including the plain film, the standing film and the lateral film. After that, the mice were sacrificed and the esophagus of the mice was isolated and embedded in sections for pathological and immunohistochemical diagnosis. Finally, the results were compared with the imaging results.

RESULTS

Based on the comparison of imaging and pathological results, we found that most of the esophageal segments with filling defects on esophagography were pathologically diagnosed as esophageal squamous cell carcinoma, and another part were diagnosed as esophageal papilloma. Compared with CT and MRI, esophagography has the advantages of simple operation and less consumable materials.

CONCLUSION

We found that esophagography is a new non-invasive auxiliary diagnostic method for the successful establishment of an orthotopic mouse model of esophageal squamous cell carcinoma.