Objective To investigate the dosimetric effect of a biological optimization approach combining physical optimization with generalized equivalent uniform dose(gEUD)on hippocampus avoidance whole-brain radiotherapy(HA-WBRT).Methods A retrospective review was conducted of 20 patients with multiple brain metastases who underwent whole-brain radiotherapy at a certain hospital between May 2021 and December 2022.Two radiotherapy plans including plan_DV and plan_gEUD were designed for each patient by using Eclipse V15.6 planning system.Plan_DB used conven-tional dose-volume(DV)physical optimization,and plan_gEUD went through re-optimization with an Upper gEUD function applied to hippocampal region and hippocampal protection zone.Evaluation was carried out in accordance with RTOG 0933 guidance for the absolute values D2%,D98%and D50%received by 2%,98%,and 50%of the target volume in the planning target volume,conformity index(CI),homogeneity index(HI),gradient index(GI)and the dosimetric indexes of hippocampal region,hippocampal protection zone and other organs at risk(OARs).SPSS 26.0 software was used for statistical analysis.Results The two kinds of plans both had the target volume coverage meet the requirements of RTOG 0933 guidance.Plan_gEUD had the D98%,D2%and V105 of the planning target volume lower than those of plan_DV,with the differences being statistically significant(all P<0.05).The two kinds of plans had no significant differences in monitor unit,D50%and Dmax of PTV,HI,CI and GI(all P>0.05).Plan_gEUD had the Dmax and Dmean of hippocampal region and them of hippocampal pro-tection zone lower than those of plan_DV,and the optic nerve Dmax of plan_gEUD was higher than that of plan_DV,with the differences being statistically significant(all P<0.05).There were no statistically significant differences between the two kinds of plans in the Dmax of inner ear,optic chiasm,lens,and eyeball(all P>0.05).Conclusion Physical optimization in the HA-WBRT plan combined with gEUD optimization results in a greater dose reduction to the hippocampus while maintaining target coverage.

Objective:To study the association between subtypes of hypertension and risk for all-cause mortality and cardio-cerebrovascular mortalities in the elderly in communities of Beijing.Methods:The data were collected from the Beijing Healthy Aging Cohort Study. The elderly in 5 urban areas (former Xicheng, former Xuanwu, Fangshan, Haidian and Tongzhou) and 4 rural areas (Yanqing, Miyun, Huairou and Daxing) in Beijing were selected as the study subjects by multi-stage stratified cluster random sampling. The baseline survey was conducted from July 2009 to September 2015. The follow-up was conducted until March 31, 2021, and a total of 6 326 participants were enrolled. Cox proportional hazard regression model was used to analyze the association of SBP, DBP, normal blood pressure, high normal blood pressure, simple systolic hypertension, simple diastolic hypertension and systolic diastolic hypertension with all-cause mortality and cardio-cerebrovascular mortality.Results:By March 31, 2021, the median follow-up time was 6.30 years, the all-cause mortality density was 201.67/10 000 person-years, and the cardio-cerebrovascular mortality density was 90.20/10 000 person-years. Multivariate Cox proportional hazard regression model analysis showed that the risk for all-cause mortality increased by 5.6% ( HR=1.056, 95% CI: 1.020-1.092), and the risk for cardio-cerebrovasculvar mortality increased by 12.5% ( HR=1.125, 95% CI: 1.071-1.182) for every 10 mmHg increase in SBP. The risk for all-cause mortality increased by 8.6% ( HR=1.086, 95% CI: 1.023-1.152), and the risk for cardio-cerebrovascular mortality increased by 19.9% ( HR=1.199, 95% CI: 1.101-1.306) for every 10 mmHg increase in DBP. Compared with the normal blood pressure group, the risk for all-cause mortality increased by 64.8% ( HR=1.648, 95% CI: 1.049-2.591) and the risk for cardio- cerebrovascular mortality increased by 112.8% ( HR=2.128, 95% CI: 1.069-4.233) in the simple diastolic hypertension group. The risk for all-cause mortality increased by 34.4% ( HR=1.344, 95% CI: 1.023-1.467) and the risk for cardio-cerebrovascular mortality increased by 111.3% ( HR=2.113, 95% CI: 1.384-3.225) in the systolic-diastolic hypertension group. Conclusions:In the elderly in communities of Beijing, beside systolic-diastolic hypertension. It is necessary to pay close attention to the simple diastolic hypertension, which has lower prevalence, and give targeted prevention and treatment.

Objective:To investigate the association of urinary albumin-to-creatinine ratio (UACR) in normal range and cardiovascular health (CVH) score with cardio-cerebroascular and all-cause mortality in urban elderly residents in Beijing.Methods:Based on Beijing Healthy Aging Cohort Study, data from 1 817 elderly participants with normal UACR were analyzed, and UACR was used as both continuous and categorical variable. "Life's Essential 8" was used to develop a CVH score. Statistical analysis was performed by using software SPSS 26.0 and R 4.2.1, including two independent samples t-test, χ2 test and non-parametric test. Multivariable Cox proportional hazard regression models stratified by CVH score and the restricted cubic spline were used to analyse the association of UACR with the risk for cardio-cerebrovascular and all-cause mortality. Results:By March 31, 2021, the median follow-up time M ( Q1, Q3) was 11.28 (10.84, 11.36) years, a total of 308 deaths were recorded during follow-up, and the mortality density was 163.87/10 000 person-years. The age of the participants was (71.4±6.6) years, and 1 070 participants were women. The results showed that the risk for both cardio-cerebrovascular disease and all-cause mortality decreased with the decrease of UACR in the low CVH score group ( HR=0.500, 95% CI: 0.341-0.734; HR=0.793, 95% CI: 0.647-0.971), and in the high CVH score group, there was a decreasing trend in the risk for cardio-cerebrovascular mortality with the decrease of UACR ( HR=0.665, 95% CI: 0.447-0.990). Compared with the participants with low CVH score and higher UACR, the risk for cardio-cerebrovascular and all-cause mortality decreased by 68.9% and 45.6%, respectively, in the participants with high CVH score and lower UACR ( HR=0.311, 95% CI: 0.131-0.739; HR=0.544, 95% CI: 0.360-0.822), and the risk for all-cause mortality decreased by 26.7% in the participants with high CVH score and higher UACR ( HR=0.733, 95% CI: 0.542-0.993). Conclusions:In urban elderly residents in Beijing, higher UACR were associated with a significantly increased risk for cardio-cerebrovascular and all-cause mortality, and in the low-CVH score group, decreased UACR was protective factor against cardio-cerebrovascular and all-cause mortality. The combined effect of cardiovascular health status and normal UACR had a greater protection against the risk for cardio-cerebrovascular and all-cause mortality.

Objective:To describe and analyze the distribution characteristics of a body shape index (ABSI) and its association with all-cause mortality in the elderly in communities of Beijing.Methods:The baseline and follow-up data of 10 423 subjects in Beijing Healthy Aging Cohort Study were used. The endpoint outcome was all-cause mortality in follow-up. The associations of ABSI, BMI and waist circumference with all-cause mortality were analyzed with a Cox proportional hazard regression model.Results:The mean follow-up time in this cohort was 6.36 years and the all-cause mortality was 15.27%. The restricted cubic spline results showed that ABSI showed a "U" association with all-cause mortality in the total population. After adjustment for confounding factors, compared with the normal ABSI group, the risk for all-cause mortality was higher in the low ABSI group ( HR=1.69, 95% CI: 1.32-2.17) and high ABSI group ( HR=1.75, 95% CI: 1.40-2.18). Compared with the normal BMI group, low BMI was associated with an increased risk for all-cause mortality ( HR=1.70, 95% CI: 1.40-2.08). Compared with the normal waist circumference group, central obesity was associated with a decreased risk for all-cause mortality ( HR=0.89, 95% CI: 0.80-0.99). The results of gender specific analysis on ABSI association with all-cause mortality were similar to that in total population, but the strength of association varied among different age groups. Cross-grouping results showed that older people with normal BMI and waist circumference and abnormal ABSI had an increased risk of all-cause mortality ( HR=1.91, 95% CI: 1.22-2.99). Conclusions:In Beijing, ABSI is correlated with the risk for all-cause mortality in the elderly population, which is more sensitive and specific than the traditional indicators (BMI and waist circumference). They can be used as one of the physical measurement indicators for all-cause mortality risk prediction in the health risk assessment and management in the elderly.

Objective:To explore the association between physical activity (PA) level and all-cause mortality in the elderly with different obesity status in Beijing.Methods:The study subjects were from the Cardiovascular and Cognitive Healthy Study in Middle-Aged and Elderly Residents of Beijing, a total of 3 746 individuals aged ≥60 years in the baseline survey between 2013 and 2015 were included in the study. Questionnaire survey and physical examination were conducted to collect the basic information of the individuals. The metabolic equivalent of the elderly was used to calculate the PA level, and an international PA questionnaire was used to determine the PA intensity. BMI, waist-to-height ratio (WHtR) and a body shape index (ABSI) were used to evaluate individuals' obesity status. The distribution of different PA levels under different obesity states was described by using bar chart and cumulative percentage bar chart. Cox proportional hazard regression model was used to analyze the correlation between the level of PA and all-cause mortality risk in different types of obesity status.Results:By December 31, 2019, the median follow-up time was 5.46 years, and the mortality density was 244.55/10 000 person-years. Compared with the individuals in high-PA intensity group, the all-cause mortality risk increased by 41% ( HR=1.41, 95% CI: 1.14-1.76) and 122% ( HR=2.22, 95% CI: 1.76-2.81), respectively, in moderate and low PA intensity groups. Compared with the individuals in high-PA intensity-high-obesity group, based on the BMI, the all-cause mortality risk increased by 85% ( HR=1.85, 95% CI: 1.08-3.16) and 250% ( HR=3.50, 95% CI: 2.01-6.10) in those in moderate-PA intensity-high-obesity group and in low-intensity-high-obesity group. Based on the WHtR, the all-cause mortality risk increased by 53% ( HR=1.53, 95% CI: 1.02-2.29) and 218% ( HR=3.18, 95% CI: 2.09-4.86), respectively, in those with moderate-PA intensity-high-obesity and those with low-PA intensity-high-obesity. According to the ABSI, the all-cause mortality risk increased by 120% in those in low-PA intensity-high-obesity group ( HR=2.20, 95% CI: 1.53-3.18). Based on any one of the indicators BMI, WHtR, or ABSI, there was no significant difference in all-cause mortality risk between high-intensity-moderate-obesity group and high-intensity-low-obesity group (all P>0.05). Conclusions:PA level is closely associated with the all-cause mortality risk in the elderly in communities of Beijing. Increasing PA level can not only reduce the all-cause mortality risk but also reduce even eliminate the excess all-cause mortality risk associated with obesity.

Objective:To analyze the association between different lipid indicators and cardio-cerebrovascular mortality in the elderly, identify a better lipid indicator for the risk for cardio-cerebrovascular mortality in the elderly in communities of Beijing.Methods:The elderly aged 60 years and above were selected from the Beijing Healthy Aging Cohort Study from July 2009 to September 2015. Remnant cholesterol (RC) was derived by calculation. The Cox proportional hazard regression models determined the HR and 95% CI incidating the associations of baseline different lipid indicators with cardio-cerebrovascular and all-cause mortality. Results:By March 31, 2021, with a mean follow-up duration of 6.88 years in the study population, a total of 492 cardio-cerebrovascular deaths and 1 056 all-cause deaths wre recorded. The HR values indicating the association between LDL-C, HDL-C, and RC were 0.87 (95% CI: 0.78-0.97), 0.46 (95% CI: 0.35-0.62), and 1.29 (95% CI: 1.14-1.45) for cardio-cerebrovascular mortality, respectively, and 0.93 (95% CI: 0.86-1.00), 0.66 (95% CI: 0.55-0.80) and 1.22 (95% CI: 1.12-1.33) for all-cause mortality. The associations of RC and HDL-C with cardio-cerebrovascular mortality were consistent regardless of hyperlipidemia in the elderly. Subgroup analyses showed that elevated RC was associated with increased risk for cardio-cerebrovascular mortality, and elevated HDL-C was associated with decreased risk for cardio-cerebrovascular mortality in the elderly in different gender, age, smoking status, drinking status, and diabetes status groups in communities of Beijing. Conclusion:RC might be a better potential lipid indicator for the risk for cardio-cerebrovascular mortality in the elderly in communities compared with traditional cholesterol indicator.

Radiotherapy is an important part of the standard treatment regimen for rectal cancer, bringing survival benefits and improved quality of life to patients with rectal cancer. However, the radiotherapy resistance of rectal cancer patients greatly limits the effectiveness of treatment and affects the prognosis of patients. The emergence of nanoparticles provides a new way to improve radiotherapy resistance of rectal cancer, which can overcome radiotherapy resistance by inhibiting DNA damage repair, affecting cell cycle, targeting delivery, enhancing DNA damage, and regulating tumor microenvironment, etc. In this article, complex coordination mechanism leading to radiotherapy resistance in rectal cancer was reviewed, current relevant studies on nanoparticles in improving radiotherapy response in rectal cancer were summarized, and the feasibility and future research direction of the combination of nanoparticles and radiotherapy in clinical treatment of rectal cancer were discussed.

Objective:To study the association between subtypes of hypertension and risk for all-cause mortality and cardio-cerebrovascular mortalities in the elderly in communities of Beijing.Methods:The data were collected from the Beijing Healthy Aging Cohort Study. The elderly in 5 urban areas (former Xicheng, former Xuanwu, Fangshan, Haidian and Tongzhou) and 4 rural areas (Yanqing, Miyun, Huairou and Daxing) in Beijing were selected as the study subjects by multi-stage stratified cluster random sampling. The baseline survey was conducted from July 2009 to September 2015. The follow-up was conducted until March 31, 2021, and a total of 6 326 participants were enrolled. Cox proportional hazard regression model was used to analyze the association of SBP, DBP, normal blood pressure, high normal blood pressure, simple systolic hypertension, simple diastolic hypertension and systolic diastolic hypertension with all-cause mortality and cardio-cerebrovascular mortality.Results:By March 31, 2021, the median follow-up time was 6.30 years, the all-cause mortality density was 201.67/10 000 person-years, and the cardio-cerebrovascular mortality density was 90.20/10 000 person-years. Multivariate Cox proportional hazard regression model analysis showed that the risk for all-cause mortality increased by 5.6% ( HR=1.056, 95% CI: 1.020-1.092), and the risk for cardio-cerebrovasculvar mortality increased by 12.5% ( HR=1.125, 95% CI: 1.071-1.182) for every 10 mmHg increase in SBP. The risk for all-cause mortality increased by 8.6% ( HR=1.086, 95% CI: 1.023-1.152), and the risk for cardio-cerebrovascular mortality increased by 19.9% ( HR=1.199, 95% CI: 1.101-1.306) for every 10 mmHg increase in DBP. Compared with the normal blood pressure group, the risk for all-cause mortality increased by 64.8% ( HR=1.648, 95% CI: 1.049-2.591) and the risk for cardio- cerebrovascular mortality increased by 112.8% ( HR=2.128, 95% CI: 1.069-4.233) in the simple diastolic hypertension group. The risk for all-cause mortality increased by 34.4% ( HR=1.344, 95% CI: 1.023-1.467) and the risk for cardio-cerebrovascular mortality increased by 111.3% ( HR=2.113, 95% CI: 1.384-3.225) in the systolic-diastolic hypertension group. Conclusions:In the elderly in communities of Beijing, beside systolic-diastolic hypertension. It is necessary to pay close attention to the simple diastolic hypertension, which has lower prevalence, and give targeted prevention and treatment.

Objective:To investigate the association of urinary albumin-to-creatinine ratio (UACR) in normal range and cardiovascular health (CVH) score with cardio-cerebroascular and all-cause mortality in urban elderly residents in Beijing.Methods:Based on Beijing Healthy Aging Cohort Study, data from 1 817 elderly participants with normal UACR were analyzed, and UACR was used as both continuous and categorical variable. "Life's Essential 8" was used to develop a CVH score. Statistical analysis was performed by using software SPSS 26.0 and R 4.2.1, including two independent samples t-test, χ2 test and non-parametric test. Multivariable Cox proportional hazard regression models stratified by CVH score and the restricted cubic spline were used to analyse the association of UACR with the risk for cardio-cerebrovascular and all-cause mortality. Results:By March 31, 2021, the median follow-up time M ( Q1, Q3) was 11.28 (10.84, 11.36) years, a total of 308 deaths were recorded during follow-up, and the mortality density was 163.87/10 000 person-years. The age of the participants was (71.4±6.6) years, and 1 070 participants were women. The results showed that the risk for both cardio-cerebrovascular disease and all-cause mortality decreased with the decrease of UACR in the low CVH score group ( HR=0.500, 95% CI: 0.341-0.734; HR=0.793, 95% CI: 0.647-0.971), and in the high CVH score group, there was a decreasing trend in the risk for cardio-cerebrovascular mortality with the decrease of UACR ( HR=0.665, 95% CI: 0.447-0.990). Compared with the participants with low CVH score and higher UACR, the risk for cardio-cerebrovascular and all-cause mortality decreased by 68.9% and 45.6%, respectively, in the participants with high CVH score and lower UACR ( HR=0.311, 95% CI: 0.131-0.739; HR=0.544, 95% CI: 0.360-0.822), and the risk for all-cause mortality decreased by 26.7% in the participants with high CVH score and higher UACR ( HR=0.733, 95% CI: 0.542-0.993). Conclusions:In urban elderly residents in Beijing, higher UACR were associated with a significantly increased risk for cardio-cerebrovascular and all-cause mortality, and in the low-CVH score group, decreased UACR was protective factor against cardio-cerebrovascular and all-cause mortality. The combined effect of cardiovascular health status and normal UACR had a greater protection against the risk for cardio-cerebrovascular and all-cause mortality.

Objective:To describe and analyze the distribution characteristics of a body shape index (ABSI) and its association with all-cause mortality in the elderly in communities of Beijing.Methods:The baseline and follow-up data of 10 423 subjects in Beijing Healthy Aging Cohort Study were used. The endpoint outcome was all-cause mortality in follow-up. The associations of ABSI, BMI and waist circumference with all-cause mortality were analyzed with a Cox proportional hazard regression model.Results:The mean follow-up time in this cohort was 6.36 years and the all-cause mortality was 15.27%. The restricted cubic spline results showed that ABSI showed a "U" association with all-cause mortality in the total population. After adjustment for confounding factors, compared with the normal ABSI group, the risk for all-cause mortality was higher in the low ABSI group ( HR=1.69, 95% CI: 1.32-2.17) and high ABSI group ( HR=1.75, 95% CI: 1.40-2.18). Compared with the normal BMI group, low BMI was associated with an increased risk for all-cause mortality ( HR=1.70, 95% CI: 1.40-2.08). Compared with the normal waist circumference group, central obesity was associated with a decreased risk for all-cause mortality ( HR=0.89, 95% CI: 0.80-0.99). The results of gender specific analysis on ABSI association with all-cause mortality were similar to that in total population, but the strength of association varied among different age groups. Cross-grouping results showed that older people with normal BMI and waist circumference and abnormal ABSI had an increased risk of all-cause mortality ( HR=1.91, 95% CI: 1.22-2.99). Conclusions:In Beijing, ABSI is correlated with the risk for all-cause mortality in the elderly population, which is more sensitive and specific than the traditional indicators (BMI and waist circumference). They can be used as one of the physical measurement indicators for all-cause mortality risk prediction in the health risk assessment and management in the elderly.