OBJECTIVE:To assess the efficacy and safety of transcranial magnetic stimulation in the treatment of refractory depression and to compare the differences in efficacy between various transcranial magnetic stimulation treatment protocols in refractory depression,thereby providing a theoretical basis for the clinical selection of transcranial magnetic stimulation treatment protocols.METHODS:A comprehensive search was conducted across multiple databases,including PubMed,Embase,Cochrane Library,Web of Science,CNKI,WanFang Data,CBM and VIP.The search terms were"transcranial magnetic stimulation,treatment-resistant depression,randomized controlled trial"in Chinese,and"depressive disorder,treatment-resistant,transcranial magnetic stimulation,randomized controlled trial"in English.The objective was to identify randomized controlled trials on the treatment of patients with refractory depression published from the establishment of the databases to September 2024.The quality of the included studies was evaluated using the Cochrane risk of bias assessment tool,version 5.1.0,and the Physiotherapy Evidence Database scale.Meta-analysis of the outcome indicators was conducted using the Review Manager 5.4 and Stata 18.0 software.RESULTS:(1)Following a comprehensive review,20 randomized controlled trials were included in the analysis.All of the trials were assessed to be of high or very high quality according to the Physiotherapy Evidence Database scale.(2)Meta-analysis results showed that,compared with the sham stimulation group,high-frequency repetitive transcranial magnetic stimulation could significantly reduce the scores of Hamilton Depression Rating Scale[mean difference(MD)=-3.89,95％confidence interval(CI):-6.14 to-1.65,P＜0.05)or the Montgomery Depression Rating Scale(MD=-3.97,95％CI:-6.57 to-1.36,P＜0.05).(3)The probability ranking results of the network Meta-analysis showed that,in terms of the Hamilton Depression Rating Scale score,the probability ranking results were as follows:high-frequency repetitive transcranial magnetic stimulation(69.9％)＞intermittent theta burst stimulation(62.8％)＞bilateral theta pulse stimulation(57.5％)＞low-frequency repetitive transcranial magnetic stimulation(54.9％)＞bilateral sequential transcranial magnetic stimulation(49.0％)＞transcranial pulsed electromagnetic field(37.0％)＞sham stimulation(18.9％).And in terms of the Montgomery Depression Rating Scale score,the probability ranking results were as follows:high-frequency repetitive transcranial magnetic stimulation(93.3％)＞bilateral theta pulse stimulation(50.3％)＞sham stimulation(45.9％)＞low-frequency repetitive transcranial magnetic stimulation(32.1％)＞bilateral sequential transcranial magnetic stimulation(28.4％).CONCLUSION:Transcranial magnetic stimulations can improve the depressive symptoms of patients with treatment-resistant depression.Among them,the high-frequency repetitive transcranial magnetic stimulation mode has the best effect on improving the depressive symptoms of patients with treatment-resistant depression,followed by the intermittent θ burst stimulation mode.

OBJECTIVE:To assess the efficacy and safety of transcranial magnetic stimulation in the treatment of refractory depression and to compare the differences in efficacy between various transcranial magnetic stimulation treatment protocols in refractory depression,thereby providing a theoretical basis for the clinical selection of transcranial magnetic stimulation treatment protocols.METHODS:A comprehensive search was conducted across multiple databases,including PubMed,Embase,Cochrane Library,Web of Science,CNKI,WanFang Data,CBM and VIP.The search terms were"transcranial magnetic stimulation,treatment-resistant depression,randomized controlled trial"in Chinese,and"depressive disorder,treatment-resistant,transcranial magnetic stimulation,randomized controlled trial"in English.The objective was to identify randomized controlled trials on the treatment of patients with refractory depression published from the establishment of the databases to September 2024.The quality of the included studies was evaluated using the Cochrane risk of bias assessment tool,version 5.1.0,and the Physiotherapy Evidence Database scale.Meta-analysis of the outcome indicators was conducted using the Review Manager 5.4 and Stata 18.0 software.RESULTS:(1)Following a comprehensive review,20 randomized controlled trials were included in the analysis.All of the trials were assessed to be of high or very high quality according to the Physiotherapy Evidence Database scale.(2)Meta-analysis results showed that,compared with the sham stimulation group,high-frequency repetitive transcranial magnetic stimulation could significantly reduce the scores of Hamilton Depression Rating Scale[mean difference(MD)=-3.89,95％confidence interval(CI):-6.14 to-1.65,P＜0.05)or the Montgomery Depression Rating Scale(MD=-3.97,95％CI:-6.57 to-1.36,P＜0.05).(3)The probability ranking results of the network Meta-analysis showed that,in terms of the Hamilton Depression Rating Scale score,the probability ranking results were as follows:high-frequency repetitive transcranial magnetic stimulation(69.9％)＞intermittent theta burst stimulation(62.8％)＞bilateral theta pulse stimulation(57.5％)＞low-frequency repetitive transcranial magnetic stimulation(54.9％)＞bilateral sequential transcranial magnetic stimulation(49.0％)＞transcranial pulsed electromagnetic field(37.0％)＞sham stimulation(18.9％).And in terms of the Montgomery Depression Rating Scale score,the probability ranking results were as follows:high-frequency repetitive transcranial magnetic stimulation(93.3％)＞bilateral theta pulse stimulation(50.3％)＞sham stimulation(45.9％)＞low-frequency repetitive transcranial magnetic stimulation(32.1％)＞bilateral sequential transcranial magnetic stimulation(28.4％).CONCLUSION:Transcranial magnetic stimulations can improve the depressive symptoms of patients with treatment-resistant depression.Among them,the high-frequency repetitive transcranial magnetic stimulation mode has the best effect on improving the depressive symptoms of patients with treatment-resistant depression,followed by the intermittent θ burst stimulation mode.

ObjectiveTo develop a nomogram-based risk prediction model for chronic obstructive pulmonary disease (COPD) incidence among the community-dwelling population aged 40 years old and above, so as to provide targeted references for the screening and prevention of COPD. MethodsBased on a natural population cohort in suburban Shanghai, a total of 3 381 randomly selected participants aged ≥40 years underwent pulmonary function tests between July and October 2021. Cox stepwise regression analysis was used to develop overall and gender-specific risk prediction models, along with the construction of corresponding risk nomograms. Model predictive performance was evaluated using the C-indice, area under the curve (AUC) values, and Brier score. Stability was assessed through 10-fold cross-validation and sensitivity analysis. ResultsA total of 3 019 participants were included, with a median follow-up duration of 4.6 years. The COPD incidence density was 17.22 per 1 000 person-years, significantly higher in males (32.04/1 000 person-years) than that in females (7.38/1 000 person-years) (P<0.001). The overall risk prediction model included the variables such as gender, age, education level, BMI, smoking, passive smoking, and respiratory comorbidities. The male-specific model incorporated the variables such as age, BMI, respiratory comorbidities, and smoking, while the female-specific model included age, marital status, respiratory comorbidities, and pulmonary tuberculosis history. The C-indices for the overall, male-specific, and female-specific models were 0.829, 0.749, and 0.807, respectively. The 5-year AUC values were 0.785, 0.658, and 0.811, with Brier scores of 0.103, 0.176, and 0.059, respectively. Both 10-fold cross-validated C-indices and sensitivity analysis (excluding participants with a follow-up duration of <6 months) yielded C-indices were above 0.740. ConclusionThis study developed concise and practical overall and gender-specific COPD risk prediction models and corresponding nomograms. The models demonstrated robust performance in predicting COPD incidence, providing a valuable reference for identifying high-risk populations and formulating targeted screening and personalized management strategies.

ObjectiveTo observe the clinical efficacy of the stasis-dispelling and detoxifying therapy in endometriosis （EMs） patients with the syndrome of kidney deficiency and blood stasis and the effects of this therapy on the expression levels of proteins related to the c-Jun N-terminal kinase （JNK） signaling pathway. MethodsA total of 72 patients with EMs due to kidney deficiency and blood stasis who met the criteria at the Integrated Traditional Chinese and Western Medicine Center for Reproduction and Genetics of the Affiliated Hospital of Shandong University of Traditional Chinese Medicine from March 2024 to February 2025 were selected and randomized into a treatment group and a control group， with 36 patients in each group. Another 36 patients undergoing in vitro fertilization-embryo transfer （IVF-ET） due to male factors alone were selected as the blank group. The treatment group took the Zishen Quyu Jiedu formula orally， while the control group and the blank group took placebos. The treatment course encompassed the cycle before ovarian stimulation and the oocyte retrieval cycle. The TCM syndrome score of kidney deficiency and blood stasis， as well as the serum level of cancer antigen 125 （CA125）， were evaluated at the time of enrollment （before treatment） and on the trigger day （after treatment）. Serum levels of sex hormones were measured on day 2 of the menstrual cycle. On the trigger day， the duration and dosage of gonadotropin （Gn） administration and the serum levels of hormones on the day of human chorionic gonadotropin （HCG） injection were assessed. Embryo outcomes were evaluated 3 days after oocyte retrieval， and clinical pregnancy rates were assessed 28 days after embryo transfer. The baseline data of three groups were observed. The TCM syndrome scores and serum CA125 levels before and after treatment were compared between the treatment and control groups. The baseline endocrine levels， Gn days， Gn dosage， hormone levels on the day of HCG administration， number of oocytes retrieved， number of 2 pronucleus （2PN） fertilizations， number of available embryos， high-quality embryo rate， and clinical pregnancy rate were also assessed in all three groups. Six patients from each group were selected for determination of the protein levels of JNK， c-Jun， and nuclear receptor subfamily 4 group A member 2 （NR4A2） in ovarian granulosa cells （GCs） on the day of oocyte retrieval by Western blot. Results（1） There were no statistically significant differences in the baseline data among three groups， indicating comparability. （2） Compared with the baseline within the same group， the treatment group showed a decrease in the syndrome score of kidney deficiency and blood stasis after treatment. After treatment， serum CA125 levels decreased in both groups （P<0.05）， with a more substantial reduction in the treatment group， resulting in a difference between the two groups （P<0.05）. （3） There were no significant differences among three groups in terms of baseline serum levels of follicle-stimulating hormone （FSH）， luteinizing hormone （LH）， estradiol （E₂）， and progesterone （P）， as well as the duration and dosage of Gn administration and the serum levels of LH， E₂， and P on the day of HCG administration. （4） For embryo outcomes， the number of oocytes retrieved， 2PN fertilizations， available embryos， and high-quality embryo rates in the treatment group and the blank group were higher than those in the control group （P<0.05）， and the treatment group and the blank group had similar 2PN fertilizations. （5） There were differences in clinical pregnancy rate among three groups （P<0.05）， and the treatment group had higher pregnancy rate than the control and blank groups. （6） The protein levels of JNK， c-Jun， and NR4A2 in the GCs of the treatment group were lower than those in the control group （P<0.01） and close to those in the blank group （P<0.01）. （7） No obvious adverse reactions were observed in any of the subjects during the clinical observation process. ConclusionZishen Quyu Jiedu formula can ameliorate the clinical symptoms of patients with EMs due to kidney deficiency and blood stasis， reduce the serum CA125 level， increase the number of oocytes retrieved， 2PN fertilizations， available embryos， and high-quality embryo rate， and improve pregnancy outcomes. The mechanism may involve downregulating the levels of JNK， c-Jun， and NR4A2 to reduce the apoptosis of ovarian GCs and improve the ovarian function in the patients.

ObjectiveTo observe the clinical efficacy of the stasis-dispelling and detoxifying therapy in endometriosis （EMs） patients with the syndrome of kidney deficiency and blood stasis and the effects of this therapy on the expression levels of proteins related to the c-Jun N-terminal kinase （JNK） signaling pathway. MethodsA total of 72 patients with EMs due to kidney deficiency and blood stasis who met the criteria at the Integrated Traditional Chinese and Western Medicine Center for Reproduction and Genetics of the Affiliated Hospital of Shandong University of Traditional Chinese Medicine from March 2024 to February 2025 were selected and randomized into a treatment group and a control group， with 36 patients in each group. Another 36 patients undergoing in vitro fertilization-embryo transfer （IVF-ET） due to male factors alone were selected as the blank group. The treatment group took the Zishen Quyu Jiedu formula orally， while the control group and the blank group took placebos. The treatment course encompassed the cycle before ovarian stimulation and the oocyte retrieval cycle. The TCM syndrome score of kidney deficiency and blood stasis， as well as the serum level of cancer antigen 125 （CA125）， were evaluated at the time of enrollment （before treatment） and on the trigger day （after treatment）. Serum levels of sex hormones were measured on day 2 of the menstrual cycle. On the trigger day， the duration and dosage of gonadotropin （Gn） administration and the serum levels of hormones on the day of human chorionic gonadotropin （HCG） injection were assessed. Embryo outcomes were evaluated 3 days after oocyte retrieval， and clinical pregnancy rates were assessed 28 days after embryo transfer. The baseline data of three groups were observed. The TCM syndrome scores and serum CA125 levels before and after treatment were compared between the treatment and control groups. The baseline endocrine levels， Gn days， Gn dosage， hormone levels on the day of HCG administration， number of oocytes retrieved， number of 2 pronucleus （2PN） fertilizations， number of available embryos， high-quality embryo rate， and clinical pregnancy rate were also assessed in all three groups. Six patients from each group were selected for determination of the protein levels of JNK， c-Jun， and nuclear receptor subfamily 4 group A member 2 （NR4A2） in ovarian granulosa cells （GCs） on the day of oocyte retrieval by Western blot. Results（1） There were no statistically significant differences in the baseline data among three groups， indicating comparability. （2） Compared with the baseline within the same group， the treatment group showed a decrease in the syndrome score of kidney deficiency and blood stasis after treatment. After treatment， serum CA125 levels decreased in both groups （P<0.05）， with a more substantial reduction in the treatment group， resulting in a difference between the two groups （P<0.05）. （3） There were no significant differences among three groups in terms of baseline serum levels of follicle-stimulating hormone （FSH）， luteinizing hormone （LH）， estradiol （E₂）， and progesterone （P）， as well as the duration and dosage of Gn administration and the serum levels of LH， E₂， and P on the day of HCG administration. （4） For embryo outcomes， the number of oocytes retrieved， 2PN fertilizations， available embryos， and high-quality embryo rates in the treatment group and the blank group were higher than those in the control group （P<0.05）， and the treatment group and the blank group had similar 2PN fertilizations. （5） There were differences in clinical pregnancy rate among three groups （P<0.05）， and the treatment group had higher pregnancy rate than the control and blank groups. （6） The protein levels of JNK， c-Jun， and NR4A2 in the GCs of the treatment group were lower than those in the control group （P<0.01） and close to those in the blank group （P<0.01）. （7） No obvious adverse reactions were observed in any of the subjects during the clinical observation process. ConclusionZishen Quyu Jiedu formula can ameliorate the clinical symptoms of patients with EMs due to kidney deficiency and blood stasis， reduce the serum CA125 level， increase the number of oocytes retrieved， 2PN fertilizations， available embryos， and high-quality embryo rate， and improve pregnancy outcomes. The mechanism may involve downregulating the levels of JNK， c-Jun， and NR4A2 to reduce the apoptosis of ovarian GCs and improve the ovarian function in the patients.

OBJECTIVES: To investigate the association between methylation levels of tumor suppressing subtransferable candidate 1 (TSSC1) and melanophilin (MLPH) genes in peripheral blood and coronary heart disease (CHD) in Chinese population. METHODS: This case-control study was conducted in 86 CHD patients and 95 healthy individuals, whose methylation levels of TSSC1 and MLPH genes in peripheral blood were determined using mass spectrometry. Mann-Whitney U test was used to compare the methylation levels in different subgroups. The correlation of TSSC1 and MLPH gene methylation levels with age and gender were evaluated using Spearman correlation coefficient and contingency coefficient, respectively. RESULTS: Compared with the healthy individuals, the CHD patients showed a significant correlation between MLPH hypermethylation and myocardial infarction (MI) (MLPH_CpG_2.7: P=0.045; MLPH_CpG_3/cg06639874: P=0.049; MLPH_CpG_5: P=0.019), and this correlation was even stronger in individuals below 65 years of age (MLPH_CpG_2.7: P=0.014; MLPH_CpG_4: P=0.001) and in male subjects (MLPH_CpG_2.7: P=0.004; MLPH_CpG_3/cg06639874: P=0.044). The methylation level of TSSC1 gene in peripheral blood was not found to correlate with CHD or its subtypes. CONCLUSIONS Our findings suggest a correlation of MLPH hypermethylation in peripheral blood with CHD and MI in Chinese population, especially in individuals below 65 years and in male individuals.
Humans ; DNA Methylation ; Male ; Female ; Middle Aged ; Case-Control Studies ; Aged ; Coronary Disease/blood* ; Adult ; CpG Islands

Objective To explore the efficacy of Yishen Yangyin Gujing Prescription[derived from Zuogui Wan(Bolus for Replenishing Kidney-Yin)]for the treatment of diabetic nephropathy in type 2 diabetes mellitus(T2DM)with qi and yin deficiency syndrome,and to observe its effects on inflammatory responses,pancreatic β-cell function and renal function.Methods A total of 162 T2DM patients with diabetic nephropathy of qi and yin deficiency syndrome who admitted to the Affiliated Hospital of Shaanxi University of Chinese Medicine from May 2020 to July 2023 were randomly divided into an observation group and a control group according to the random number table method,with 81 cases in each group.The control group was given conventional western medicine treatment for lowering blood pressure and renal protection,while the observation group was treated with Yishen Yangyin Gujing Prescription on the basis of treatment for the control group.The course of treatment for the two groups covered 12 weeks.Before and after the treatment,the changes in the outcomes of the two groups were observed,and the outcomes included the total scores of traditional Chinese medicine(TCM)syndrome,insulin sensitivity index,insulin secretion index,24-h urine total protein quantification(24hUTP),and serum levels of glycosylated hemoglobin(HbA1c),fasting insulin(FINS),fasting blood glucose(FBG),serum creatinine(SCr),blood urea nitrogen(BUN),transforming growth factor β1(TGF-β1),NLRP3 inflammasome,interleukin 6(IL-6),superoxide dismutase(SOD)and sphingosine-1-phosphate(S1P).After treatment,the clinical efficacy of the two groups of patients was compared.Results(1)After 12-week treatment,the total effective rate of the observation group was 93.83%(76/81),and that of the control group was 83.95%(68/81).The intergroup comparison showed that the efficacy of the observation group was significantly superior to that of the control group(χ2=9.163,P<0.05).(2)After treatment,the insulin sensitivity index and insulin secretion index in the two groups of patients were increased(P<0.05)and the total scores of TCM syndromes were decreased(P<0.05)when compared with those before treatment,and the increase of insulin sensitivity index and insulin secretion index as well as the decrease of the total scores of TCM syndrome in the observation group was significantly superior to that in the control group(P<0.05).(3)After treatment,the serum levels of HbA1c,FINS,FBG,SCr,BUN and 24hUTP in the two groups of patients were decreased when compared with those before treatment(P<0.05),and the decrease of the above indicators in the observation group was significantly superior to that in the control group(P<0.05).(4)After treatment,the serum TGF-β1,IL-6,and NLRP3 inflammasome levels in the two groups of patients were decreased(P<0.05)and the serum S1P and SOD levels were increased(P<0.05)when compared with those before treatment,and the decrease of serum TGF-β1,IL-6,and NLRP3 inflammasome levels as well as the increase of serum S1P and SOD levels in the observation group was significantly superior to that in the control group(P<0.05).Conclusion For T2DM patients with diabetic nephropathy of qi and yin deficiency syndrome,the combined use of western medicine and Yishen Yangyin Gujing Prescription treatment is helpful to alleviate inflammatory response,improve the function of pancreatic β-cells,regulate the blood glucose level,improve renal function,and enhance the clinical efficacy.

Objective To discuss the effect of different particle activities and tumor shrinkage speed on the dosimetric parameters of the target area at the same prescription dose after 125I particle implantation.Methods A 6cm-sized cube tumor model was outlined by using a computerized three-dimensional treatment planning system(3D-TPS)with a prescription dose(PD)of 100 Gy,and 125I particle activities of 0.4 mCi and 0.8 mCi were selected.Assuming that the tumor shrinks centripetally after seed implantation and that the 125I particles were uniformly and centripetally concentrated without shedding or wandering,the tumor volume shrank at different rates every month after implantation(0,5％,10％,15％,20％,25％,30％,35％,40％,45％and 50％),according to the different activities of 125I particles,the experiments were divided into A1-K1 group(0.4 mCi)and A2-K2 group(0.8 mCi).Based on the 125I particle decay law,the validation program(using TPS simulation of the A1-K1 group and A2-K2 group at postoperative 1,2,3,4,5 and 6 months)obtained the dose received by 90％of the target volume(D90)in the two groups with different 125I particle activities at different postoperative time points,the percentages of the target volume covered by the 100％,150％and 90％prescription dose(V100,V150,V90),and the mean dose(Dmean).By comparing the differences in D90,V100,V150,V90 and Dmean after tumor implantation of 125I particles with different activities,the dosimetric impact of the tumor target area shrinking at a rate of 0～50％after implantation of 125I particles with different activities into tumor tissues was analyzed.Results When the monthly shrinkage rate of the tumor target area was≤30％,there was no obvious difference in D90 between the 0.4 mCi group and 0.8 mCi group in 1～6 months after surgery.When the monthly shrinkage rate of the tumor target area was＞30％,the D90 of 0.8 mCi group was higher than that of 0.4 mCi group;when the monthly shrinkage rate of the tumor target area was＜25％,the V90 of 0.4 mCi group was higher than that of 0.8 mCi group,and the changes of V90 of the two groups tended to be the same in the 5th～6th month after surgery.When the monthly shrinkage rate of the tumor target area was ≥30％,the V90 of 0.8 mCi group was higher than that of 0.4 mCi group,and with the increasing of shrinkage rate,the difference between the two groups become more and more significant,the results of V100 were consistent with those of V90.When the monthly shrinkage rate of tumor target area＜35％,V150 of 0.4 mCi group was higher than that of 0.8 mCi group,when the monthly shrinkage rate of tumor target area ≥35％,V150 of 0.8 mCi group was higher than that of 0.4 mCi group,and with the increasing of shrinkage rate,the difference between the two groups become more and more prominent.When the monthly shrinkage rate of tumor target area＜25％,Dmean of 0.4 mCi group was higher than that of 0.8 mCi group,when the monthly shrinkage rate of tumor target area ≥25％,Dmean of 0.8 mCi group was higher than that of 0.4 mCi group,and with the increasing of shrinkage rate,the difference between the two groups become more and more obvious.Conclusion With the same prescription dose,when the tumor target area shrinks at a rate of＜30％per month,the activity of 125I particles has little effect on D90,and all V90,V100,V150 and Dmean in the low activity group are higher than those in the high activity group,meanwhile the homogeneity of the target area is relatively good;when the monthly shrinkage rate of tumor target area ≥35％,all D90,V90,V100,V150 and Dmean in the high activity group are higher than those in the low activity group,and the duration of the presence of high-dose area is long.This difference becomes more obvious with the increasing of the monthly shrinkage rate of the target area.

Objective To investigate the effect of different strand lengths of 125I seeds with the same activity on the dose of different reference points around the seeds.Methods The scanned images were transferred to the three-dimensional treatment planning system(3D-TPS)according to DICOM format.The target volume was delineated at 5 mm and 10 mm above and below the center of the phantom,and a 0.8 mCi seeds strand was simulated.The 1-20 seeds were arranged with an equal spacing of 5 mm(5 mm-100 mm).The 5 mm points above and below the center of the seeds strand were defined as point A and point A',and the 10 mm points above and below the center were defined as point B and point B'.5 mm above and below the edge of the seeds strand on the left side were defined as AL points and AL'points,and 5 mm above and below the edge of the seeds strand on the right side were defined as AR points and AR'points.Similarly,points 10 mm above the above mentioned positions were defined as BL points,BL'points,BR points,BR'points.The average dose symmetry points were measured at AL,AL',AR,and 5 mm,10 mm,15 mm and 20 mm inside AR' of the 45 mm-100 mm seeds strand.The dose at the center was compared with the dose at the end points.The dose at the center point A was compared with the average dose at the symmetry points of 5 mm,10 mm,15 mm and 20 mm inside of the end points AL,AL',AR and AR',and the dose at each point was curve fitting.The correlation between each point and seeds strands of different lengths was analyzed.Results There was a positive correlation between the dose and the length of each point.There was no statistically significant difference between the center point and the end point.There was a statistically significant difference in dosage at points 5 mm and 10 mm inside from point A,while there was no statistically significant difference in dosage at points 15 mm and 20 mm inside from point A.The dose of A,A',B and B' point increased steadily with the increase of seed chain length,and the fitting curves were obtained respectively:y=e(-0.620/x+5.28)(R2=0.992),y=e(-0.640/x+5.34)(R2=0.987),y=e(-0.82/x+4.80)(R2=0.984),y=e(-0.82/x+4.83)(R2=0.9g1).Conclusion The doses at points A,A',B,and B'are positively correlated with seeds strand length and have a high degree of stability.Point A can be used as a reference point for the target area dose of the seeds strand,and point B can be used as a reference point for the dose to critical organs.The dose at other positions is more variable and thus has a certain degree of uncertainty as a reference point for the seeds strand dose.

Objective To investigate the relationship between the absorbed dose and implantation duration at the target area and at the critical organ dose reference points in the application of radioactive 125I seed strands for the treatment of intraluminal tumors.Methods A self-developed 125I seed strand arc template with a 30-degree angle was used to place 10 seeds(each with activity of 1.0mCi)into the template.CT-based DICOM images were transferred to a treatment planning system(TPS)for dose calculation.Absorbed doses at multiple time points(from day 5 to day 90 with a 5-day interval)were measured at following four specific locations:point A'(5 mm inside the arc center),point A(5 mm outside the arc center),point B(10 mm outside the arc center),and point B'(10 mm inside the arc center).The TPS was first used to calculate the expected absorbed doses,followed by actual absorbed dose measurements over the 90-day period.The expected absorbed doses were calculated,and then the actual absorbed doses were calculated.The time-dose relationship of the above points was analyzed,and the curves and equations were obtained.Results The expected absorbed doses at points A',A,B,and B'were 221.36,196.39,115.78,and 136.32 Gy,respectively.The time(x)-dose(y)relationships of all the above points followed a quadratic function relationship in the form of y=c+bx-ax2.Within the time range of 5-90 days,the actual absorbed dose increased with the prolongation of time,and the increase speed showed a pattern of first fast and then slow.The increase in speed was fast within 20 days,than became stable between 20-75 days,and after 75 days the increase in speed became to slow down.Conclusion When using 125I seed strands to treat intraluminal tumors,the actual absorbed dose of the tumor needs to be accurately calculated based on the implantation duration.The actual absorbed dose initially accumulates rapidly and decreases significantly after 75 days.It is recommended to replace the 125I seed strand with a new one after implanting it for approximately 75 days.