Objective:To investigate the feasibility and optimal expansion width of replacing the left anterior descending coronary artery (LADCA) with the region of heart sparing (RHS) to reduce cardiac radiation dose during breast cancer radiotherapy.Methods:Retrospective analysis was conducted on data from 88 patients with left-sided breast cancer who underwent radiotherapy at 2 centers: Nanfang Hospital of Southern Medical University (50 cases for the training set, 15 cases for the internal test set) and Ganzhou Hospital of Nanfang Hospital (23 cases for the external test set) from March 2022 to January 2024. All patients had left-sided invasive ductal carcinoma with axillary lymph node metastasis, and had undergone modified radical mastectomy and chemotherapy. Based on simulation CT images, 2 radiation oncologists delineated the LADCA and 8 RHSs. The RHSs were delineated by expanding the LADCA contour by 0.5 cm increments, totaling 8 expansions. The RHS widths were defined as 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 cm. The nnU-Net model was trained for 3D automatic segmentation of the LADCA and RHSs. Model performance was evaluated using the Dice similarity coefficient (DSC), relative volume error (RVE), sensitivity, specificity, and 95% Hausdorff distance (HD95). Additionally, the minimum, maximum, and average relative dose variations (RDV) as well as V5% and V20% indicators were calculated for the LADCA and each RHS. Correlation analysis was performed using the least squares regression, with the slope and coefficient of determination ( R2) employed to evaluate the accuracy of the model fitting, the relationship between the LADCA and RHS, and the degree of their correlation, thereby assessing the substitutive effect of the RHS for the LADCA. Results:The DSC for the LADCA was 0.415, while the DSCs for RHS widths of 0.5 cm and 4.0 cm were 0.718 and 0.835, respectively. Overall, the automatic segmentation performance improved with increasing RHS width. The DSC, RVE, sensitivity, specificity, and HD95 for the external test set were largely consistent with those of the internal test set, demonstrating the model's good robustness across different datasets. All RDVmin values were negative, while RDVmax and RDVmean showed a positive correlation with RHS width. RDVmean increased from 39.01% to 75.89% as the RHS width increased. In the correlation analysis, the slopes for RHS widths of 1.5 cm and 2.0 cm were 0.95 and 1.05, respectively, with R2 values and coefficients of variation of 0.79 and 0.73, and 21.11% and 24.03%, respectively. Conclusions:The automatic segmentation model trained on nnU-Net can accurately segment RHSs. Based on geometric and dosimetric indicators, a 1.5 cm-wide RHS is the most suitable substitute for the LADCA, effectively limiting the radiation dose to the LADCA without compromising target dose coverage.

Objective:To investigate the feasibility and optimal expansion width of replacing the left anterior descending coronary artery (LADCA) with the region of heart sparing (RHS) to reduce cardiac radiation dose during breast cancer radiotherapy.Methods:Retrospective analysis was conducted on data from 88 patients with left-sided breast cancer who underwent radiotherapy at 2 centers: Nanfang Hospital of Southern Medical University (50 cases for the training set, 15 cases for the internal test set) and Ganzhou Hospital of Nanfang Hospital (23 cases for the external test set) from March 2022 to January 2024. All patients had left-sided invasive ductal carcinoma with axillary lymph node metastasis, and had undergone modified radical mastectomy and chemotherapy. Based on simulation CT images, 2 radiation oncologists delineated the LADCA and 8 RHSs. The RHSs were delineated by expanding the LADCA contour by 0.5 cm increments, totaling 8 expansions. The RHS widths were defined as 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 cm. The nnU-Net model was trained for 3D automatic segmentation of the LADCA and RHSs. Model performance was evaluated using the Dice similarity coefficient (DSC), relative volume error (RVE), sensitivity, specificity, and 95% Hausdorff distance (HD95). Additionally, the minimum, maximum, and average relative dose variations (RDV) as well as V5% and V20% indicators were calculated for the LADCA and each RHS. Correlation analysis was performed using the least squares regression, with the slope and coefficient of determination ( R2) employed to evaluate the accuracy of the model fitting, the relationship between the LADCA and RHS, and the degree of their correlation, thereby assessing the substitutive effect of the RHS for the LADCA. Results:The DSC for the LADCA was 0.415, while the DSCs for RHS widths of 0.5 cm and 4.0 cm were 0.718 and 0.835, respectively. Overall, the automatic segmentation performance improved with increasing RHS width. The DSC, RVE, sensitivity, specificity, and HD95 for the external test set were largely consistent with those of the internal test set, demonstrating the model's good robustness across different datasets. All RDVmin values were negative, while RDVmax and RDVmean showed a positive correlation with RHS width. RDVmean increased from 39.01% to 75.89% as the RHS width increased. In the correlation analysis, the slopes for RHS widths of 1.5 cm and 2.0 cm were 0.95 and 1.05, respectively, with R2 values and coefficients of variation of 0.79 and 0.73, and 21.11% and 24.03%, respectively. Conclusions:The automatic segmentation model trained on nnU-Net can accurately segment RHSs. Based on geometric and dosimetric indicators, a 1.5 cm-wide RHS is the most suitable substitute for the LADCA, effectively limiting the radiation dose to the LADCA without compromising target dose coverage.

Objective To study the expression of epidermal growth factor receptor (EGFR) in cervical car-cinoma and cervical intraepithelial neoplasia(CIN),and to elucidate its relation with the genesis, infiltration, metas-tasis and prognosis of cervical carcinoma. Methods EGFR was determined by means of S-P immunohistochemistry in tissue of 100 cases of cervical carcinoma,60 cases of CIN and 40 cases of controls. Results The overexpression rates of EGFR were 0% (0/40), 51.67% (31/60),78.00% (78/100), respectively in normal cervical epithelium, CIN and cervical tumor tissues. The overexpression rate of EGFR was significantly higher in cervical tumor tissue than in control group(P<0.01). The overexpression of EGFR didn't demonstrate significant association with clinical staging, tumor size, pathological type, differentiation, cervical invasion depth, cervical canal invasion, lymphnode me-tastasis or the prognosis of cervical neoplasm (P>0.05). Conclusion Overexpression of EGFR is worsened with the severity of cervical lesion, suggesting that overexpression of EGFR is correlated with the genesis of cervical neo-plasms,which may be a valuable biological indicator of cervical carcinoma,but is not correlated with clinical patho-logical features and prognosis of cervical carcinoma.

Objective To evaluate the clinical effect of ambulatory labor analgesia used in latent phase of the first stage of labor, which include labor progress, Apgar score after ambulatory labor analgesia begun to use when the cervix was different size dilatated. Methods Seventy-five parturient primiparas who had no complication were randomly divided into three groups: group Ⅰ: ambulatory labor analgesia was begun to use when the cervix was 1.0 cm dilated, group Ⅱ: ambulatory labor analgesia was begun to use when the cervix was 2-3 cm dilated, group Ⅲ: control group without use of ambulatory labor analgesia. Analgesic effects were observed, changes of uterine contraction were recorded by fetal monitor. Meanwhile, total stage of labor ,outcome of delivery and Apgar score were recorded. Results Duration of total stage of labor had no significant difference between group Ⅰ and group Ⅲ.The duration of the first labor stage was significantly longer in group Ⅰ than that in group Ⅱ(P

Objective To explore safety of severe preeclampsia by amniotic infusion therapy.Methods 58 cases with severe preeclampsia during 28 to 34 weeks pregnancy had been practised intravenous infusion as controls(37 cases).Results Ultrasound guided amnioinfusion were all succesful in therapy group,there was no maternal complication.Statistical difference was found in premature infant apgar score between therapy group and control group.The incidence of respiratory distress syndrome was 3.4%,whereas that of the control group was 35.1%(P