Objective:To investigate whether there is an association between the total dose of breast cancer radiotherapy, the mean dose of radiation field involving the heart and its substructures, and the long-term incidence of coronary heart disease (CHD) in patients.Methods:A retrospective analysis was conducted on 1125 patients with breast cancer who received radiotherapy with radiation fields involving the hear at Beijing Hospital from January 2009 to June 2022. The heart and its substructures of 54 patients were manually delineated, trained an automatic delineation model, and applied this model to the original radiotherapy planning images to automatically extract dosimetric parameters for the heart and substructures in the original plan. Based on the follow-up results, 1125 breast cancer patients were categorized into the CHD event group ( n=19) and non-event group ( n=1106). Wilcoxon rank-sum test, Chi-square test and adjustment for confounding factors using inverse probability weighting were used to compare the mean radiation dose received by the heart and its substructures, age at presentation, history of smoking, history of alcohol consumption, history of hypertension, and history of diabetes between two groups. The influencing factors of CHD were analyzed by univariate and multivariate logistic regression models. Results:The mean heart dose ( P=0.035), mean dose of right atrium ( P=0.049), right coronary artery ( P=0.013), septum ( P=0.045), and right ventricle ( P=0.039) of the event group were higher than that of the non-event group, and the differences were statistically significant. History of alcohol consumption was an independent risk factor for long-term CHD events in the breast cancer patients ( OR=7.35,95% CI: 1.56-25.58, P=0.004). After adjusting for confounding factors using inverse probability weighting, age at presentation was an independent risk factor for long-term CHD events ( OR=1.03, 95% CI: 1.01-1.05, P=0.004). Conclusions:In the breast cancer population with traditional high-risk factors of CHD receiving radiotherapy, the possibility of CHD probably remains high even if the dose of radiation field involving the heart and its substructures is low. Compared to traditional risk factors of CHD, the mean dose to the heart and its substructures in the radiation field of breast cancer patients exerts less impact on the occurrence of CHD after radiotherapy.

Objective:To investigate whether there is an association between the total dose of breast cancer radiotherapy, the mean dose of radiation field involving the heart and its substructures, and the long-term incidence of coronary heart disease (CHD) in patients.Methods:A retrospective analysis was conducted on 1125 patients with breast cancer who received radiotherapy with radiation fields involving the hear at Beijing Hospital from January 2009 to June 2022. The heart and its substructures of 54 patients were manually delineated, trained an automatic delineation model, and applied this model to the original radiotherapy planning images to automatically extract dosimetric parameters for the heart and substructures in the original plan. Based on the follow-up results, 1125 breast cancer patients were categorized into the CHD event group ( n=19) and non-event group ( n=1106). Wilcoxon rank-sum test, Chi-square test and adjustment for confounding factors using inverse probability weighting were used to compare the mean radiation dose received by the heart and its substructures, age at presentation, history of smoking, history of alcohol consumption, history of hypertension, and history of diabetes between two groups. The influencing factors of CHD were analyzed by univariate and multivariate logistic regression models. Results:The mean heart dose ( P=0.035), mean dose of right atrium ( P=0.049), right coronary artery ( P=0.013), septum ( P=0.045), and right ventricle ( P=0.039) of the event group were higher than that of the non-event group, and the differences were statistically significant. History of alcohol consumption was an independent risk factor for long-term CHD events in the breast cancer patients ( OR=7.35,95% CI: 1.56-25.58, P=0.004). After adjusting for confounding factors using inverse probability weighting, age at presentation was an independent risk factor for long-term CHD events ( OR=1.03, 95% CI: 1.01-1.05, P=0.004). Conclusions:In the breast cancer population with traditional high-risk factors of CHD receiving radiotherapy, the possibility of CHD probably remains high even if the dose of radiation field involving the heart and its substructures is low. Compared to traditional risk factors of CHD, the mean dose to the heart and its substructures in the radiation field of breast cancer patients exerts less impact on the occurrence of CHD after radiotherapy.

In this study,the loop-mediated isothermal amplification(LAMP)method was used to develop a rapid and simple detection system for porcine circovirus type 2(PCV2).According to the PCV2 sequences published in GenBank,multiple LAMP primers were designed targeting conserved sequences of PCV2.Using the DNA extracted from PCV2 isolates HUN-09 and SD-09 as the template,LAMP reactions in a PCV2 LAMP system was performed,the amplification products were detected by adding SYBR Green I and could be observed directly by the naked eye.The results showed highly-efficient and specific amplification in 30 min at 63℃ with a LAMP real-time turbidimeter.Furthermore,PCV2 DNA templates,with a detection limit of 5.5×10-5ng of nucleic acid,indicated that this assay was highly sensitive.The results obtained with the naked eye after SYBR Green I staining were consistent with those detected by the real-time turbidimeter,showing the potential simplicity of interpretation of the assay results.The LAMP assay appeared to have greater accuracy than PCR and virus isolation for the analysis of 18 clinical samples.In addition it offers higher specificity and sensitivity,shorter reaction times and simpler procedures than the currently available methods of PCV2 detection.It is therefore a promising tool for the effective and efficient detection of PCV2.