1.Coronary artery stenosis associated with right ventricular dysfunction in acute pulmonary embolism: A case-control study.
Yuejiao MA ; Jieling MA ; Dan LU ; Yinjian YANG ; Chao LIU ; Liting WANG ; Xijie ZHU ; Xianmei LI ; Chunyan CHENG ; Sijin ZHANG ; Jiayong QIU ; Jinghui LI ; Mengyi LIU ; Kai SUN ; Xin JIANG ; Xiqi XU ; Zhi-Cheng JING
Chinese Medical Journal 2025;138(16):2028-2036
BACKGROUND:
The potential impact of pre-existing coronary artery stenosis (CAS) on right ventricular (RV) function during acute pulmonary embolism (PE) episodes remains underexplored. This study aimed to investigate the association between pre-existing CAS and RV dysfunction in patients with acute PE.
METHODS:
In this multicenter, case-control study, 89 cases and 176 controls matched for age were enrolled at three study centers (Peking Union Medical College Hospital, Fuwai Hospital, and the Second Affiliated Hospital of Harbin Medical University) from January 2016 to December 2020. The cases were patients with acute PE with CAS, and the controls were patients with acute PE without CAS. Coronary artery assessment was performed using coronary computed tomographic angiography. CAS was defined as ≥50% stenosis of the lumen diameter in any coronary vessel >2.0 mm in diameter. Conditional logistic regression analysis was used to evaluate the association between CAS and RV dysfunction.
RESULTS:
The percentages of RV dysfunction (19.1% [17/89] vs. 44.6% [78/176], P <0.001) and elevated systolic pulmonary artery pressure (sPAP) (19.3% [17/89] vs. 39.5% [68/176], P = 0.001) were significantly lower in the case group than those in the control group. In the multivariable logistic regression model, CAS was independently and negatively associated with RV dysfunction (adjusted odds ratio [OR]: 0.367; 95% confidence interval [CI]: 0.185-0.728; P = 0.004), and elevated sPAP (OR: 0.490; 95% CI: 0.252-0.980; P = 0.035), respectively.
CONCLUSIONS
Pre-existing CAS was significantly and negatively associated with RV dysfunction and elevated sPAP in patients with acute PE. This finding provides new insights into RV dysfunction in patients with acute PE with pre-existing CAS.
Humans
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Pulmonary Embolism/complications*
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Case-Control Studies
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Male
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Ventricular Dysfunction, Right/physiopathology*
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Female
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Middle Aged
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Aged
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Coronary Stenosis/complications*
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Logistic Models
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Adult
2.Genetically predicted waist circumference and risk of atrial fibrillation
Wenting WANG ; Jiang-Shan TAN ; Jingyang WANG ; Wei XU ; Liting BAI ; Yu JIN ; Peng GAO ; Peiyao ZHANG ; Yixuan LI ; Yanmin YANG ; Jinping LIU
Chinese Medical Journal 2024;137(1):82-86
Introduction::Observational studies have revealed an association between waist circumference (WC) and atrial fibrillation (AF). However, it is difficult to infer a causal relationship from observational studies because the observed associations could be confounded by unknown risk factors. Therefore, the causal role of WC in AF is unclear. This study was designed to investigate the causal association between WC and AF using a two-sample Mendelian randomization (MR) analysis.Methods::In our two-sample MR analysis, the genetic variation used as an instrumental variable for MR was acquired from a genome-wide association study (GWAS) of WC (42 single nucleotide polymorphisms with a genetic significance of P <5 × 10 –8). The data of WC (from the Genetic Investigation of ANthropometric Traits consortium, containing 232,101 participants) and the data of AF (from the European Bioinformatics Institute database, containing 55,114 AF cases and 482,295 controls) were used to assess the causal role of WC on AF. Three different approaches (inverse variance weighted [IVW], MR–Egger, and weighted median regression) were used to ensure that our results more reliable. Results::All three MR analyses provided evidence of a positive causal association between high WC and AF. High WC was suggested to increase the risk of AF based on the IVW method (odds ratio [OR] = 1.43, 95% confidence interval [CI], 1.30–1.58, P = 2.51 × 10 -13). The results of MR–Egger and weighted median regression exhibited similar trends (MR–Egger OR = 1.40 [95% CI, 1.08–1.81], P = 1.61 × 10 -2; weighted median OR = 1.39 [95% CI, 1.21–1.61], P = 1.62 × 10 -6). MR–Egger intercepts and funnel plots showed no directional pleiotropic effects between high WC and AF. Conclusions::Our findings suggest that greater WC is associated with an increased risk of AF. Taking measures to reduce WC may help prevent the occurrence of AF.
3.Age-related changes of alveolar bone in maxillary posterior based on cone-beam CT
Meng ZHAO ; Liting JIANG ; Yiming GAO
Journal of Shanghai Jiaotong University(Medical Science) 2024;44(10):1273-1278
Objective·To measure and analyze age-related changes in cortical bone thickness and alveolar bone height and width in the posterior teeth of the maxilla.Methods·Cone-beam CT(CBCT)data of the implant patients in the Department of Stomatology,Ruijin Hospital,Shanghai Jiao Tong University School of Medicine were collected from January 2019 to December 2022.There were 40 cases in the youth group(18?30 years)and 40 cases in the elderly group(≥60 years),with a male-to-female ratio of 1∶1.The i-Dixel software was used to measure the thickness of buccal and palatal cortical bone,and the width and height of alveolar bone in three regions of the posterior teeth of the maxilla on the side with regular dentition(part Ⅰ:between the first and the second premolar of maxillary;part Ⅱ:between the second premolar and the first molar of maxillary;part Ⅲ:between the first and the second molar of maxillary),and the differences between different groups were compared.Results·In part Ⅲ,the buccal cortical bone thickness of the elderly men[(1.49±0.29)mm]was significantly greater than that of the young men[(1.11±0.34)mm](P<0.001).In part Ⅰ and Ⅱ,the thickness of palatal cortical bone in the elderly women[part Ⅰ:(1.27±0.30)mm;part Ⅱ:(1.28±0.27)mm]was significantly smaller than that in the young women[part Ⅰ:(1.70±0.32)mm;part Ⅱ:(1.58±0.61)mm](P<0.05).The width of alveolar bone showed a trend of being smaller in the elderly group than in the young group in all three regions,but there were significant differences only between the elderly males[part Ⅱ:(8.61±1.15)mm;part Ⅲ:(11.06±2.40)mm]and the young males[part Ⅱ:(10.29±1.69)mm;part Ⅲ:(13.39±1.59)mm]in the part Ⅱ and Ⅲ(P<0.05).The alveolar bone height in part Ⅰ andⅡ was significantly greater in elderly men and women than that in the young men and women,respectively(P<0.05).In the elderly group,the thickness of buccal cortical bone in men was significantly greater than that in women in part Ⅰ and Ⅲ(P<0.05).Conclusion·The thickness of palatal cortical bone in female maxillary posterior teeth significantly decreases with age;the width of alveolar bone in maxillary posterior region shows a narrowing trend with age,especially in elderly men;the height of alveolar bone in the maxillary posterior region of the elderly increases significantly.
4.Construction of a model based on multipoint full-layer puncture biopsy for predicting pathological complete response after neoadjuvant therapy for locally advanced rectal cancer
Ying JIN ; Zhiwei ZHAI ; Liting SUN ; Pingdian XIA ; Hang HU ; Chongqiang JIANG ; Baocheng ZHAO ; Hao QU ; Qun QIAN ; Yong DAI ; Hongwei YAO ; Zhenjun WANG ; Jiagang HAN
Chinese Journal of Gastrointestinal Surgery 2024;27(4):403-411
Objective:To investigate the value of transanal multipoint full-layer puncture biopsy (TMFP) in predicting pathological complete response (pCR) after neoadjuvant radiotherapy and chemotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to establish a predictive model for providing clinical guidance regarding the treatment of LARC.Methods:In this multicenter, prospective, cohort study, we collected data on 110 LARC patients from four hospitals between April 2020 and March 2023: Beijing Chaoyang Hospital of Capital Medical University (50 patients), Beijing Friendship Hospital of Capital Medical University (41 patients), Qilu Hospital of Shandong University (16 patients), and Zhongnan Hospital of Wuhan University (three patients). The patients had all received TMFP after completing standard nCRT. The variables studied included (1) clinicopathological characteristics; (2) clinical complete remission (cCR) and efficacy of TMFP in determining pCR after NCRT in LARC patients; and (3) hospital attended, sex, age, clinical T- and N-stages, distance between the lower margin of the tumor and the anal verge, baseline and post-radiotherapy serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 concentrations, chemotherapy regimen, use of immunosuppressants with or without radiotherapy, radiation therapy dosage, interval between surgery and radiotherapy, surgical procedure, clinical T/N stage after radiotherapy, cCR, pathological results of TMFP, puncture method (endoscopic or percutaneous), and number and timing of punctures. Single-factor and multifactorial logistic regression analysis were used to determine the factors affecting pCR after NCRT in LARC patients. A prediction model was constructed based on the results of multivariat analysis and the performance of this model evaluated by analyzing subject work characteristics (ROC), calibration, and clinical decision-making (DCA) curves. pCR was defined as complete absence of tumor cells on microscopic examination of the surgical specimens of rectal cancer (including lymph node dissection) after NCRT, that is, ypT0+N0. cCR was defined according to the Chinese Neoadjuvant Rectal Cancer Waiting Watch Database Study Collaborative Group criteria after treatment, which specify an absence of ulceration and nodules on endoscopy; negative rectal palpation; no tumor signals on rectal MRI T2 and DWI sequences; normal serum CEA concentrations, and no evidence of recurrence on pelvic computed tomography/magnetic resonance imaging.Results:Of the 110 patients, 45 (40.9%) achieved pCR after nCRT, which was combined with immune checkpoint inhibitors in 34 (30.9%). cCR was diagnosed before puncture in 38 (34.5%) patients, 43 (39.1%) of the punctures being endoscopic. There were no complications of puncture such as enterocutaneous fistulae, vaginal injury, prostatic injury, or presacral bleeding . Only one (2.3%) patient had a small amount of blood in the stools, which was relieved by anal pressure. cCR had a sensitivity of 57.8% (26/45) for determining pCR, specificity of 81.5% (53/65), accuracy of 71.8% (79/110), positive predictive value 68.4% (26/38), and negative predictive value of 73.6% (53/72). In contrast, the sensitivity of TMFP pathology in determining pCR was 100% (45/45), specificity 66.2% (43/65), accuracy 80.0% (88/110), positive predictive value 67.2% (45/67), and negative predictive value 100.0% (43/43). In this study, the sensitivity of TMFP for pCR (100.0% vs. 57.8%, χ 2=24.09, P<0.001) was significantly higher than that for cCR. However, the accuracy of pCR did not differ significantly (80.0% vs. 71.8%, χ 2=2.01, P=0.156). Univariate and multivariate logistic regression analyses showed that a ≥4 cm distance between the lower edge of the tumor and the anal verge (OR=7.84, 95%CI: 1.48-41.45, P=0.015), non-cCR (OR=4.81, 95%CI: 1.39-16.69, P=0.013), and pathological diagnosis by TMFP (OR=114.29, the 95%CI: 11.07-1180.28, P<0.001) were risk factors for pCR after NCRT in LARC patients. Additionally, endoscopic puncture (OR=0.02, 95%CI: 0.05-0.77, P=0.020) was a protective factor for pCR after NCRT in LARC patients. The area under the ROC curve of the established prediction model was 0.934 (95%CI: 0.892-0.977), suggesting that the model has good discrimination. The calibration curve was relatively close to the ideal 45° reference line, indicating that the predicted values of the model were in good agreement with the actual values. A decision-making curve showed that the model had a good net clinical benefit. Conclusion:Our predictive model, which incorporates TMFP, has considerable accuracy in predicting pCR after nCRT in patients with locally advanced rectal cancer. This may provide a basis for more precisely selecting individualized therapy.
5.Therapeutic effect of evodiamine on atopic dermatitis in rat models
Su JIANG ; Xinxiang LYU ; Yanhong CUI ; Liting LYU ; Dongxia LI
Basic & Clinical Medicine 2024;44(9):1256-1262
Objective To evaluate the therapeutic effect of evodiamine(Evo)on atopic dermatitis(AD)in rat models by regulating the cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/cAMP response ele-ment binding protein(CREB)signaling pathway.Methods A rat model of AD was established by administration of multiple doses of 2,4-dinitrochlorobenzene(DNCB).The animals were randomly divided into AD group,Evo-low-dose(Evo-L,5 mg/kg)group,Evo-high-dose(Evo-H,10 mg/kg)group,Evo-H+H-89(5 mg/kg)group and dexamethasone(0.1 mg/kg)group.Normal rats were used as the control group and then the degree of skin damage of rats in each group was scored.Abdominal blood was taken to detect the levels of interleukin-4(IL-4),cAMP,and tumor necrosis factor-α(TNF-α)in serum;Skin lesion tissue was collected to detect pathological change,counting of mast cells,PKA/CREB related protein expression and expression of IL-4 and TNF-α mRNA in the tissue.Results Compared with control group,the level of cAMP in serum,the expression of p-PKA/PKA,and p-CREB/CREB in skin lesions of AD group were reduced,the severity score of skin lesions,level of IL-4 and TNF-α,epidermal thickness,number of mast cells and mRNA expression of IL-4 and TNF-α in skin lesion tissues were all significantly increased(P<0.05).Compared with AD group,the level of cAMP in serum,the expression of p-PKA/PKA,and p-CREB/CREB in skin lesions in Evo-L group,Evo-H group,and dexamethasone group were increased,the severity score of skin lesions,level of IL-4 and TNF-α,epidermal thickness,number of mast cells,and mRNA expression of IL-4 and TNF-α in skin lesion tissues all reduced(P<0.05).Compared with the Evo-H group,the level of cAMP in serum,the expression of p-PKA/PKA,and p-CREB/CREB in skin lesions in Evo-H+H-89 group was reduced and the severity score of skin lesion,level of IL-4 and TNF-α,epidermal thickness,num-ber of mast cells,and mRNA expression of IL-4 and TNF-α in skin lesion tissues significantly increased(P<0.05).Conclusions Evo inhibits inflammatory response and pathological damage through regulation of cAMP/PKA/CREB signaling pathway in AD rat models.
6.Construction of a model based on multipoint full-layer puncture biopsy for predicting pathological complete response after neoadjuvant therapy for locally advanced rectal cancer
Ying JIN ; Zhiwei ZHAI ; Liting SUN ; Pingdian XIA ; Hang HU ; Chongqiang JIANG ; Baocheng ZHAO ; Hao QU ; Qun QIAN ; Yong DAI ; Hongwei YAO ; Zhenjun WANG ; Jiagang HAN
Chinese Journal of Gastrointestinal Surgery 2024;27(4):403-411
Objective:To investigate the value of transanal multipoint full-layer puncture biopsy (TMFP) in predicting pathological complete response (pCR) after neoadjuvant radiotherapy and chemotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to establish a predictive model for providing clinical guidance regarding the treatment of LARC.Methods:In this multicenter, prospective, cohort study, we collected data on 110 LARC patients from four hospitals between April 2020 and March 2023: Beijing Chaoyang Hospital of Capital Medical University (50 patients), Beijing Friendship Hospital of Capital Medical University (41 patients), Qilu Hospital of Shandong University (16 patients), and Zhongnan Hospital of Wuhan University (three patients). The patients had all received TMFP after completing standard nCRT. The variables studied included (1) clinicopathological characteristics; (2) clinical complete remission (cCR) and efficacy of TMFP in determining pCR after NCRT in LARC patients; and (3) hospital attended, sex, age, clinical T- and N-stages, distance between the lower margin of the tumor and the anal verge, baseline and post-radiotherapy serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 concentrations, chemotherapy regimen, use of immunosuppressants with or without radiotherapy, radiation therapy dosage, interval between surgery and radiotherapy, surgical procedure, clinical T/N stage after radiotherapy, cCR, pathological results of TMFP, puncture method (endoscopic or percutaneous), and number and timing of punctures. Single-factor and multifactorial logistic regression analysis were used to determine the factors affecting pCR after NCRT in LARC patients. A prediction model was constructed based on the results of multivariat analysis and the performance of this model evaluated by analyzing subject work characteristics (ROC), calibration, and clinical decision-making (DCA) curves. pCR was defined as complete absence of tumor cells on microscopic examination of the surgical specimens of rectal cancer (including lymph node dissection) after NCRT, that is, ypT0+N0. cCR was defined according to the Chinese Neoadjuvant Rectal Cancer Waiting Watch Database Study Collaborative Group criteria after treatment, which specify an absence of ulceration and nodules on endoscopy; negative rectal palpation; no tumor signals on rectal MRI T2 and DWI sequences; normal serum CEA concentrations, and no evidence of recurrence on pelvic computed tomography/magnetic resonance imaging.Results:Of the 110 patients, 45 (40.9%) achieved pCR after nCRT, which was combined with immune checkpoint inhibitors in 34 (30.9%). cCR was diagnosed before puncture in 38 (34.5%) patients, 43 (39.1%) of the punctures being endoscopic. There were no complications of puncture such as enterocutaneous fistulae, vaginal injury, prostatic injury, or presacral bleeding . Only one (2.3%) patient had a small amount of blood in the stools, which was relieved by anal pressure. cCR had a sensitivity of 57.8% (26/45) for determining pCR, specificity of 81.5% (53/65), accuracy of 71.8% (79/110), positive predictive value 68.4% (26/38), and negative predictive value of 73.6% (53/72). In contrast, the sensitivity of TMFP pathology in determining pCR was 100% (45/45), specificity 66.2% (43/65), accuracy 80.0% (88/110), positive predictive value 67.2% (45/67), and negative predictive value 100.0% (43/43). In this study, the sensitivity of TMFP for pCR (100.0% vs. 57.8%, χ 2=24.09, P<0.001) was significantly higher than that for cCR. However, the accuracy of pCR did not differ significantly (80.0% vs. 71.8%, χ 2=2.01, P=0.156). Univariate and multivariate logistic regression analyses showed that a ≥4 cm distance between the lower edge of the tumor and the anal verge (OR=7.84, 95%CI: 1.48-41.45, P=0.015), non-cCR (OR=4.81, 95%CI: 1.39-16.69, P=0.013), and pathological diagnosis by TMFP (OR=114.29, the 95%CI: 11.07-1180.28, P<0.001) were risk factors for pCR after NCRT in LARC patients. Additionally, endoscopic puncture (OR=0.02, 95%CI: 0.05-0.77, P=0.020) was a protective factor for pCR after NCRT in LARC patients. The area under the ROC curve of the established prediction model was 0.934 (95%CI: 0.892-0.977), suggesting that the model has good discrimination. The calibration curve was relatively close to the ideal 45° reference line, indicating that the predicted values of the model were in good agreement with the actual values. A decision-making curve showed that the model had a good net clinical benefit. Conclusion:Our predictive model, which incorporates TMFP, has considerable accuracy in predicting pCR after nCRT in patients with locally advanced rectal cancer. This may provide a basis for more precisely selecting individualized therapy.
7.Effect of tanshinone ⅡA on angiotensin Ⅱ-induced proliferation and migration of vascular smooth muscle cells
Liting LIU ; Zhiqian XIONG ; Yan JIANG ; Chaojiang SU ; Shuai ZHANG ; Zongyang LIU
Journal of China Medical University 2024;53(5):439-445
Objective To determine whether Tanshinone ⅡA(Tan ⅡA)has an effect on angiotensin Ⅱ(Ang Ⅱ)-induced prolifera-tion and migration of vascular smooth muscle cells(VSMCs),phenotypic switching,or autophagy.Methods In this study,murine aortic smooth muscle cell lines were treated with Ang Ⅱ to establish a model of cell proliferation.Different concentrations of Tan ⅡA were added and effects on cell proliferation and migration were determined by cell counting using a CCK-8 assay and a cell scratch assay,respectively.Alpha-smooth muscle actin(α-SMA),a marker of contractile VSMCs,was detected by Western blotting.Expression levels of osteopontin(OPN)and the autophagy-related proteins(p62,Beclin-1,LC3A/B)were assayed to determine the effect of Tan ⅡA on VSMC phenotypic transformation and autophagy.Cells were treated with the autophagy inhibitor 3-methyladenine(3-MA),combined with Tan ⅡA,and then cell proliferation,migration and expression levels of phenotypic markers and autophagy-related proteins were assessed.Results After Ang Ⅱ treatment,the proliferation and migratory capacity of VSMCs was significantly enhanced,and phenotypic transformation was sig-nificantly inhibited by Ang Ⅱ.Western blotting revealed that Ang Ⅱ reduced the expression of α-SMA,increased the expression of OPN,p62,Beclin-1,and LC3A/B,and that these effects increased with higher Tan ⅡA concentrations.After the addition of 3-MA to the treated cells,the proliferation and migration of VSMCs induced by Ang Ⅱ was inhibited,the expression of α-SMA was increased,and the expres-sion of OPN,p62,Beclin-1,and LC3A/B was decreased,which was consistent with the effect of Tan ⅡA.Conclusion Tan ⅡA may have inhibitory effects on phenotypic transformation,proliferation,migration,and autophagy of Ang Ⅱ-treated VSMC,suggesting that the inhi-bition of the proliferation and migration may be regulated by autophagy.
8.A study on sensory processing characteristics of preschool children with autism spectrum disorder
Lian JIANG ; Liting CHU ; Chenhuan MA ; Lingyan CHEN ; Mengfan LI ; Lizhu PAN ; Peiying ZHU ; Yu WANG
Shanghai Journal of Preventive Medicine 2022;34(10):955-959
ObjectiveTo explore the sensory processing characteristics of preschool children with autism spectrum disorder (ASD), and to provide a theoretical basis for early screening and intervention training of ASD. MethodsA total of 215 preschool children with ASD and170 typically developed (TD) children were investigated with a basic situation questionnaire and sensory processing measure (SPM). The two groups were stratified according to age and gender, and the differences of scores in sensory domains were compared to analyze the sensory processing characteristics of preschool children with ASD. ResultsThe scores of social participation, vision, hearing, touch, taste and smell, body awareness, balance and motion, planning and ideas, and total sensory system in children with ASD were all higher than those in children with TD (all P<0.01). The highest degree of abnormality was found in hearing and the lowest degree in taste and smell in children with ASD. The results of Spearman correlation analysis showed that in the 4-year-old and 5-year-old children with ASD, the scores of vision (rs=-0.200, P= 0.033) and hearing (rs=-0.194, P=0.040) decreased with age. There was no correlation between the scores of other developmental quotients and age (all P>0.05). Boys and girls with ASD had higher scores in all developmental quotients than TD children (P<0.01). However, there was no significant gender difference in any developmental quotients of ASD children (all P>0.05). ConclusionSensory processing abnormalities are common in preschool children with ASD, which are different from those of TD children in multiple sensory domains. Sensory processing abnormalities may be used as an indicator for early screening of ASD, and it is necessary to conduct corresponding intervention training for sensory processing abnormalities in children with ASD.
9.Effects of tissue heterogeneity on dose evaluation of brachytherapy for cervical cancer
Ailin WU ; Xiao JIANG ; Aidong WU ; Lei ZHU ; Yidong YANG ; Yunqin LIU ; Liting QIAN
Chinese Journal of Radiological Medicine and Protection 2021;41(7):486-491
Objective:To evaluate the impacts of tissue heterogeneity on dose calculation of cervical brachytherapy by comparing the doses calculated by two clinically used dose calculation method and the CT image-based Monte Carlo (MC) method.Methods:This study retrospectively selected 11 patients with cervical cancer treated with 3D brachytherapy in Anhui Provincial Cancer Hospital from January 2018 to June 2020. The dose distribution of each plan was calculated via three methods, dose calculation method described in American Association of Physicist in Medicine(AAPM) Task Group No. 43 Report (TG43-BT), Acuros BV(BV-BT) used to perform accurate dose calculations in high-dose-rate (HDR) brachytherapy with phantom heterogeneity, and CT image-based EGSnrc tool kit used to perform Monte Carlosimulation (MC-BT). The dose volumes( V3 Gy, V6 Gy, V9 Gy, and V12 Gy), target volume doses( D98, D90, D50), D2 cm 3 of organs at risk (OARs) calculated by the three methods were compared. Results:The HRCTV D90obtained by TG43-BT was 6.274 Gy, which was even overestimated by around 5% compared to the result calculated by MC-BT. Meanwhile, TG43-BT overestimated the dose volumesand the target volume doses compared to MC-BT.Except for D50 and V12 Gy, the differences between the doses to tumor calculated by BV-BT and MC-BT were not statistically significant( P>0.05). There was also no significant statistical difference between the D2 cm 3 of rectum, small intestine, and sigmoid calculated by BV-BT and MC-BT ( P>0.05). In contrast, the dose to D2 cm 3 of bladder determined by MC-BT was 4.609 Gy, which was notably higher than those deter mined by TG43-BT and BV-BT. Conclusions:TG43-BT overestimated the doses to tumor targets and most OARs since the effects of tissue heterogeneity were not taken into consideration. BV-BT performed efficient calculation and most of the dose distributionin target volume and OARs obtained by BV-BT were consistent with that calculated by MC-BT. Nevertheless, low accuracy occurred for the regions near the sources and full bladder, which warrants further caution in clinical evaluation.
10.Impacts of the composition and density of tissue on the dose distribution of implanted 125I seeds
Ailin WU ; Xiao JIANG ; Aidong WU ; Lei ZHU ; Yidong YANG ; Yunqin LIU ; Liting QIAN
Chinese Journal of Radiological Medicine and Protection 2021;41(11):813-817
Objective:To investigate the impacts of the composition and physical density of tissue on the dose distribution of implanted 125I seeds, in order to provide references for the clinical dose calculation and assessment of implanted radioactive particles. Methods:The OncoSeed 6711 physical model of 125I seeds was established using thes of twareegs_brachy and was validated through the calculation of dose rate constant and the radial dose function [ g( r)] in water. Then, based on the element composition and physical density of different types of tissue, the g( r) and absorbed dose ratein water, prostate, breast, muscle, and bone were calculated. Results:The calculated dose rate constant (0.950 cGy·h -1·U -1) and g( r)in water approached the values in related literature. The absorbed dose in bone was 6.042 times than that in water at a distance of 0.05 cm from the implanted source. The difference between the absorbed doses in breast and water was more than 10% at a distance of less than 1.7 cm from the implanted source. The difference between the absorbed doses in prostate/muscle and water was less than 5% at the same radial location. Conclusions:The dose distribution of 125I seeds in some types of human tissue is significantly different from that in water, which should be carefully considered in clinical dose calculation.

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