Radiation-induced adverse reactions in organs at risk(OAR) is recognized as a significant factor limiting doses to clinical target volumes(CTV). Magnetic ferrite nanoparticles, distinguished by their unique physicochemical properties such as ease of modification and high biocompatibility, have been extensively investigated in the biomedical field. This article reviews the latest advances in research on the application of magnetic ferrite nanoparticles in radiotherapy, focusing on their magnetothermal effect, dose enhancement effect, promotion of ferroptosis, regulation of the cell cycle, and improvement in image-guided quality. Furthermore, this article provides an outlook for future research.

Objective:To compare the clinical efficacy and adverse events of different postoperative radiotherapy strategies (adjuvant radiotherapy versus salvage radiotherapy) and different irradiation fields (prostate bed versus prostate bed + pelvic radiation) in patients after radical prostatectomy for prostate cancer.Methods:This retrospective analysis included clinical data from 115 patients with localized or locally advanced prostate cancer who received intensity-modulated radiotherapy (IMRT) after radical prostatectomy at Beijing Hospital between March 2014 and September 2023. Among them, 40 patients received adjuvant radiotherapy, and 75 received salvage radiotherapy. And 74 patients received irradiation to both the prostate bed and pelvic (prostate bed + pelvic radiation group), while 41 patients received irradiation to the prostate bed alone (prostate bed irradiation group). Comparison was made between the adjuvant radiotherapy group and salvage radiotherapy group, as well as between prostate bed + pelvic radiation group and prostate bed irradiation group, in terms of overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRRFS), and the incidence of adverse events. Clinical characteristics were compared using the chi-square test. Survival rates were calculated using the Kaplan-Meier method and compared using the log-rank test. Prognostic factors affecting survival were analyzed using Cox multivariate regression.Results:The median follow-up duration was 73.1 months. The 5-year OS, PFS and LRRFS rates for the entire cohort were 96.4%, 86.4%, and 93.2%, respectively. A total of 59 patients (51.3%) experienced grade 1-2 acute radiotherapy-related adverse events, while 43 patients (37.4%) experienced grade 1-2 late radiotherapy-related adverse events. No grade ≥ 3 late adverse events were observed. There were no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups ( P = 0.807, 0.996, and 0.976, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). The OS rate in the prostate bed + pelvic radiation group was significantly lower than that in the prostate bed irradiation group ( P = 0.036), while no significant differences were found in PFS or LRRFS ( P = 0.109 and 0.190, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). Multivariable analysis showed no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups, or between the prostate bed and prostate bed + pelvic irradiation groups ( P = 0.756, 0.341, 0.605; 0.938, 0.987, 0.605, respectively). Conclusions:In the era of modern IMRT, both adjuvant and salvage radiotherapy, as well as prostate bed and prostate bed + pelvic irradiation, demonstrate similar efficacy and safety profiles after radical prostatectomy for prostate cancer. Treatment outcomes were favorable, and adverse events were minimal.

Objective:To compare the treatment time stability, inter- and intra-fraction errors, and clinical target volume (CTV) to planning target volume (PTV) margin expansions under different gated window settings in deep inspiration breath hold (DIBH) radiotherapy for breast cancer, and to analyze the correlation between organ at risk (OAR) dose optimization and changes in lung volume.Methods:A retrospective analysis was conducted on 65 patients with left-sided breast cancer who received DIBH radiotherapy after modified radical mastectomy. CT simulation positioning was performed using 2 mm or 3 mm gated window for DIBH, followed by target delineation, treatment planning, and dose verification. During treatment, setup errors guided by cone beam CT (CBCT), intra-fraction monitoring errors, and treatment times were recorded. The coefficient of variation (CV) of treatment time was calculated for both gated window settings. Based on inter- and intra-fraction error distributions, the expansion distance of the CTV were determined using the van Herk formula. Dosimetric differences between DIBH and free-breathing (FB) plans for the left lung, heart, and left anterior descending coronary artery (LAD) were compared. Spearman correlation analysis was performed between the relative increase in left lung volume and the relative reduction in OAR dose. Paired t-tests were used for inter-group comparisons. Results:The mean CV of the 3 mm gated window group was 0.08±0.03, which was lower than that of the 2 mm group (0.10±0.04; t=-3.91, P<0.001). The setup errors of the 2 mm group in the X, Y, and Z directions were (1.27±1.03), (1.68±0.94), (1.90±1.25) mm, respectively-significantly smaller than those of the 3 mm group [(1.81±1.41), (2.07±1.69), (2.93±1.90) mm; t=-5.80, -2.33, -5.33; P<0.001,=0.014,<0.001). Setup errors for both groups were within the 25%-75% range and all below 5 mm. The intra-fraction deviations of the 2 mm group in the X, Y, and Z directions were (0.54±0.33), (0.79±0.44), (0.70±0.53) mm, respectively, significantly smaller than those of the 3 mm group [(0.62±0.43), (0.93±0.66), (0.87±0.67) mm; t=-3.87, -3.46, -2.71,all P<0.001). The mean intra-fraction errors of both groups were within 1 mm, with greater deviations in the Y and Z directions than those in the X direction. The CTV expansion margins for the 2 mm group in the X, Y, and Z directions were 4.21, 5.35, 5.99 mm, respectively, while those for the 3 mm group were 5.81, 6.89, 9.06 mm. Compared with FB, DIBH significantly reduced the doses to the left lung, heart, and LAD (all P<0.01). The increase in left lung volume was moderately negatively correlated with the reduction in left lung D mean ( r=-0.43, P=0.028), and highly negatively correlated with the dose reductions to the heart and LAD (both P<0.001). Conclusions:The variability in respiratory gated window settings can lead to differences in treatment time stability as well as inter- and intra-fraction errors, consequently affecting CTV-to-PTV margins. The DIBH technique demonstrates significant dosimetric benefits in reducing radiation exposure to the left lung, heart, and LAD. Volumetric expansion of the left lung is strongly and inversely correlated with the reduction in radiation dose to both the heart and LAD.

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.

Purpose To explore the relationship between the proportion of HER2 low expression and clinicopatho-logical characteristics of gastric adenocarcinoma patients.Methods Clinical data from 3 779 gastric adenocarcinoma patients who underwent radical resection were collected.HER2 expression was categorized using immunohistochemistry combined with FISH,and the clinicopathological characteristics and prognosis of HER2 low expression gastric adeno-carcinoma patients were analyzed.Results Among the 3 779 gastric adenocarcinoma cases,1 251 cases(33.10％)showed HER2 low expression.Compared with HER2 negative expression,HER2 low expression patients were more likely to be older males,present with well-differentiated Lauren's intestinal-type adenocarcinoma,and have less nerve invasion.Furthermore,compared to HER2 negative expression,they showed higher Ki67 proliferation index and more advanced clinical stage.Meanwhile,compared with patients with HER2 over expression,those with low HER2 expres-sion were more likely to be younger females,present with well-differentiated Lauren's diffuse-type adenocarcinoma,and have more nerve invasion.Furthermore,compared to HER2 over expression,they showed lower Ki67 proliferation index and more advanced clinical stage.There was no significant difference in prognosis between HER2 low expression,HER2 negative,and HER2 over expression groups.Conclusion HER2 low expression have a relatively large propor-tion in gastric adenocarcinoma patients,and HER2-targeted antibody-drug conjugates may provide an effective treatment option for these patients with HER2 low expression.

Radiation-induced adverse reactions in organs at risk(OAR) is recognized as a significant factor limiting doses to clinical target volumes(CTV). Magnetic ferrite nanoparticles, distinguished by their unique physicochemical properties such as ease of modification and high biocompatibility, have been extensively investigated in the biomedical field. This article reviews the latest advances in research on the application of magnetic ferrite nanoparticles in radiotherapy, focusing on their magnetothermal effect, dose enhancement effect, promotion of ferroptosis, regulation of the cell cycle, and improvement in image-guided quality. Furthermore, this article provides an outlook for future research.

Purpose To explore the relationship between the proportion of HER2 low expression and clinicopatho-logical characteristics of gastric adenocarcinoma patients.Methods Clinical data from 3 779 gastric adenocarcinoma patients who underwent radical resection were collected.HER2 expression was categorized using immunohistochemistry combined with FISH,and the clinicopathological characteristics and prognosis of HER2 low expression gastric adeno-carcinoma patients were analyzed.Results Among the 3 779 gastric adenocarcinoma cases,1 251 cases(33.10％)showed HER2 low expression.Compared with HER2 negative expression,HER2 low expression patients were more likely to be older males,present with well-differentiated Lauren's intestinal-type adenocarcinoma,and have less nerve invasion.Furthermore,compared to HER2 negative expression,they showed higher Ki67 proliferation index and more advanced clinical stage.Meanwhile,compared with patients with HER2 over expression,those with low HER2 expres-sion were more likely to be younger females,present with well-differentiated Lauren's diffuse-type adenocarcinoma,and have more nerve invasion.Furthermore,compared to HER2 over expression,they showed lower Ki67 proliferation index and more advanced clinical stage.There was no significant difference in prognosis between HER2 low expression,HER2 negative,and HER2 over expression groups.Conclusion HER2 low expression have a relatively large propor-tion in gastric adenocarcinoma patients,and HER2-targeted antibody-drug conjugates may provide an effective treatment option for these patients with HER2 low expression.

Objective:To compare the clinical efficacy and adverse events of different postoperative radiotherapy strategies (adjuvant radiotherapy versus salvage radiotherapy) and different irradiation fields (prostate bed versus prostate bed + pelvic radiation) in patients after radical prostatectomy for prostate cancer.Methods:This retrospective analysis included clinical data from 115 patients with localized or locally advanced prostate cancer who received intensity-modulated radiotherapy (IMRT) after radical prostatectomy at Beijing Hospital between March 2014 and September 2023. Among them, 40 patients received adjuvant radiotherapy, and 75 received salvage radiotherapy. And 74 patients received irradiation to both the prostate bed and pelvic (prostate bed + pelvic radiation group), while 41 patients received irradiation to the prostate bed alone (prostate bed irradiation group). Comparison was made between the adjuvant radiotherapy group and salvage radiotherapy group, as well as between prostate bed + pelvic radiation group and prostate bed irradiation group, in terms of overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRRFS), and the incidence of adverse events. Clinical characteristics were compared using the chi-square test. Survival rates were calculated using the Kaplan-Meier method and compared using the log-rank test. Prognostic factors affecting survival were analyzed using Cox multivariate regression.Results:The median follow-up duration was 73.1 months. The 5-year OS, PFS and LRRFS rates for the entire cohort were 96.4%, 86.4%, and 93.2%, respectively. A total of 59 patients (51.3%) experienced grade 1-2 acute radiotherapy-related adverse events, while 43 patients (37.4%) experienced grade 1-2 late radiotherapy-related adverse events. No grade ≥ 3 late adverse events were observed. There were no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups ( P = 0.807, 0.996, and 0.976, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). The OS rate in the prostate bed + pelvic radiation group was significantly lower than that in the prostate bed irradiation group ( P = 0.036), while no significant differences were found in PFS or LRRFS ( P = 0.109 and 0.190, respectively), or in the incidence of grade 1-2 acute or late adverse events ( P > 0.05). Multivariable analysis showed no statistically significant differences in OS, PFS, or LRRFS between the adjuvant and salvage radiotherapy groups, or between the prostate bed and prostate bed + pelvic irradiation groups ( P = 0.756, 0.341, 0.605; 0.938, 0.987, 0.605, respectively). Conclusions:In the era of modern IMRT, both adjuvant and salvage radiotherapy, as well as prostate bed and prostate bed + pelvic irradiation, demonstrate similar efficacy and safety profiles after radical prostatectomy for prostate cancer. Treatment outcomes were favorable, and adverse events were minimal.

Objective:To compare the treatment time stability, inter- and intra-fraction errors, and clinical target volume (CTV) to planning target volume (PTV) margin expansions under different gated window settings in deep inspiration breath hold (DIBH) radiotherapy for breast cancer, and to analyze the correlation between organ at risk (OAR) dose optimization and changes in lung volume.Methods:A retrospective analysis was conducted on 65 patients with left-sided breast cancer who received DIBH radiotherapy after modified radical mastectomy. CT simulation positioning was performed using 2 mm or 3 mm gated window for DIBH, followed by target delineation, treatment planning, and dose verification. During treatment, setup errors guided by cone beam CT (CBCT), intra-fraction monitoring errors, and treatment times were recorded. The coefficient of variation (CV) of treatment time was calculated for both gated window settings. Based on inter- and intra-fraction error distributions, the expansion distance of the CTV were determined using the van Herk formula. Dosimetric differences between DIBH and free-breathing (FB) plans for the left lung, heart, and left anterior descending coronary artery (LAD) were compared. Spearman correlation analysis was performed between the relative increase in left lung volume and the relative reduction in OAR dose. Paired t-tests were used for inter-group comparisons. Results:The mean CV of the 3 mm gated window group was 0.08±0.03, which was lower than that of the 2 mm group (0.10±0.04; t=-3.91, P<0.001). The setup errors of the 2 mm group in the X, Y, and Z directions were (1.27±1.03), (1.68±0.94), (1.90±1.25) mm, respectively-significantly smaller than those of the 3 mm group [(1.81±1.41), (2.07±1.69), (2.93±1.90) mm; t=-5.80, -2.33, -5.33; P<0.001,=0.014,<0.001). Setup errors for both groups were within the 25%-75% range and all below 5 mm. The intra-fraction deviations of the 2 mm group in the X, Y, and Z directions were (0.54±0.33), (0.79±0.44), (0.70±0.53) mm, respectively, significantly smaller than those of the 3 mm group [(0.62±0.43), (0.93±0.66), (0.87±0.67) mm; t=-3.87, -3.46, -2.71,all P<0.001). The mean intra-fraction errors of both groups were within 1 mm, with greater deviations in the Y and Z directions than those in the X direction. The CTV expansion margins for the 2 mm group in the X, Y, and Z directions were 4.21, 5.35, 5.99 mm, respectively, while those for the 3 mm group were 5.81, 6.89, 9.06 mm. Compared with FB, DIBH significantly reduced the doses to the left lung, heart, and LAD (all P<0.01). The increase in left lung volume was moderately negatively correlated with the reduction in left lung D mean ( r=-0.43, P=0.028), and highly negatively correlated with the dose reductions to the heart and LAD (both P<0.001). Conclusions:The variability in respiratory gated window settings can lead to differences in treatment time stability as well as inter- and intra-fraction errors, consequently affecting CTV-to-PTV margins. The DIBH technique demonstrates significant dosimetric benefits in reducing radiation exposure to the left lung, heart, and LAD. Volumetric expansion of the left lung is strongly and inversely correlated with the reduction in radiation dose to both the heart and LAD.

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.