1.The effect of different particle activities and tumor shrinkage speed on the dosimetric parameters of the target area after 125I particle implantation
Huimin YU ; Jinxin ZHAO ; Jiantao DONG ; Xuemin DI ; Zhen GAO ; Juan WANG ; Hongtao ZHANG
Journal of Interventional Radiology 2025;34(3):272-277
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.
2.GRK2 inhibits Flt-1+ macrophage infiltration and its proangiogenic properties in rheumatoid arthritis.
Xuezhi YANG ; Yingjie ZHAO ; Qi WEI ; Xuemin ZHU ; Luping WANG ; Wankang ZHANG ; Xiaoyi LIU ; Jiajie KUAI ; Fengling WANG ; Wei WEI
Acta Pharmaceutica Sinica B 2024;14(1):241-255
Rheumatoid arthritis (RA) is an autoimmune disease with a complex etiology. Monocyte-derived macrophages (MDMs) infiltration are associated with RA severity. We have reported the deletion of G-protein-coupled receptor kinase 2 (GRK2) reprograms macrophages toward an anti-inflammatory phenotype by recovering G-protein-coupled receptor signaling. However, as more GRK2-interacting proteins were discovered, the GRK2 interactome mechanisms in RA have been understudied. Thus, in the collagen-induced arthritis mouse model, we performed genetic GRK2 deletion using GRK2f/fLyz2-Cre+/- mice. Synovial inflammation and M1 polarization were improved in GRK2f/fLyz2-Cre+/- mice. Supporting experiments with RNA-seq and dual-luciferase reporter assays identified peroxisome proliferator-activated receptor γ (PPARγ) as a new GRK2-interacting protein. We further confirmed that fms-related tyrosine kinase 1 (Flt-1), which promoted macrophage migration to induce angiogenesis, was inhibited by GRK2-PPARγ signaling. Mechanistically, excess GRK2 membrane recruitment in CIA MDMs reduced the activation of PPARγ ligand-binding domain and enhanced Flt-1 transcription. Furthermore, the treatment of mice with GRK2 activity inhibitor resulted in significantly diminished CIA pathology, Flt-1+ macrophages induced-synovial inflammation, and angiogenesis. Altogether, we anticipate to facilitate the elucidation of previously unappreciated details of GRK2-specific intracellular signaling. Targeting GRK2 activity is a viable strategy to inhibit MDMs infiltration, affording a distinct way to control joint inflammation and angiogenesis of RA.
3.Research on the effects of simulated microgravity on the proliferation of skin stem cells
Siyuan WANG ; Yingsong ZHAO ; Yingjun TAN ; Liujia SHI ; Xuemin YIN ; Jianghai CHEN
Space Medicine & Medical Engineering 2024;35(2):99-104,111
Objective To study the changes and mechanism of skin stem cells in microgravity.Methods The skin stem cells of SD rats were used to establish a suspension culture system and compare the proliferation of skin stem cells with 1G gravity.Results The simulated microgravity significantly affected the velocity of skin stem cell sphere proliferation in suspension culture,which was about 12%higher than the 1G gravity group.Transcriptome sequencing showed that 1673 genes were up-regulated and 1409 genes were downregulated;Calcium signaling;cytokine-cytokine receptor interaction and PPAR pathway were different in the two environments.Conclusion Simulation of microgravity can affect the proliferation behavior of skin stem cells in suspension culture by regulating the expression of key signaling pathways,which provides an experimental basis for further research in spatial microgravity environ ment.
4.Traditional Chinese medicine pattern identification research on health status of astronauts in long term spaceflight
Hongzhi SHI ; Chong XU ; Quanchun FAN ; Junlian LIU ; Shuang ZHAO ; Tao MI ; Chengpu ZHANG ; Xuemin YIN ; Yongzhi LI
Space Medicine & Medical Engineering 2024;35(5):302-306,318
Objective To study traditional Chinese medicine(TCM)syndrome pattern of astronauts in long term spaceflight,and to summarize and elucidate the characteristics and evolvement of their holistic functional status based on TCM Pattern Identification and Classification System.Methods The Digital TCM Diagnostic Instrument and TCM Syndrome Diagnosis Scale were used to collect information from 9 astronauts in three manned missions of China Space Station,through diagnostic methods of observation,palpation and inquiry according to CM theory.Data collection was performed at various stages before,during,and after spaceflight,a total of 32 person-time digital images of tongues and facial complexion and over 2 000 data were collected.Through data mining and analysis using four diagnostic feature fusion methods,the distribution characteristics of TCM pattern among astronauts at different stages of flight and with different physical constitutions were proposed,and the health status and evolution trend of astronauts were evaluated based on the health concept of TCM.Results ⑴The astronauts showed related manifestations of 8 TCM syndromes during long term flight,among which 4 syndromes had higher scores,including Liver Depression Transforming into Fire,Liver and Kidney Yin Deficiency,Heart Kidney Disharmony,and Spleen and Kidney Yang Deficiency.However,their syndrome differentiation were mainly based on Yin and Yang in equilibrium,with only a few individuals showing a brief deviation from the equilibrium state at a certain stage.After long-term adaptation and adjustment,they almost had returned to a state of Yin-Yang equilibrium reestablishment.⑵As the flight time increased,the proportion of Liver Depression Transforming into Fire and Qi and Blood Deficiency in Heart and Spleen syndrome increased month by month,indicating that the psychological and emotional changes and insufficient Qi and blood status during long term flight need to be focused on.⑶Physical constitution had a certain impact on the syndrome patterns during flight,the astronauts with biased constitutions had significantly higher total scores for all syndrome patterns than that of individuals with Normal-constitution,astronauts with Yin deficiency had slightly higher scores for Heart Kidney Disharmony than those with Yang(Qi)deficiency,indicating that personalized TCM conditioning measures should be developed based on the pathogenesis of TCM syndrome during different flight periods,combined with factors such as physical constitution,etc.Conclusion The research has verified the scientific nature and effectiveness of TCM pattern analysis based on"four diagnostic"methods,which could be used for achieving quantitative and comprehensive evaluation of astronaut health status from the perspective of TCM in long-term space flight.
5.Research progress on relationship between N6-adenylate methylation modification and cell transformation and associated mechanism
Zhao ZHAO ; Jingjing ZHENG ; Mingxuan YANG ; Suhua WANG ; Xuemin SHI ; Yuhang ZHAO
Journal of Environmental and Occupational Medicine 2023;40(5):601-608
As a reversible and dynamic epigenetic marker, N6-adenylate methylation (m6A) modification is the most common mRNA modification in eukaryotes. This paper briefly described how m6A can influence RNA splicing, stability, and translation after transcription, and then participate in a variety of signaling pathways and biological and pathological processes, regulating cell proliferation, apoptosis, epithelial mesenchymal transformation (EMT) processes, and tumor invasion and metastasis. In addition, according to current studies, m6A methyltransferases (writers) are believed to promote EMT and tumor development, and readers and erasers both promote and inhibit EMT in different research objects. In this review, we summarized the mechanism of m6A modification and its role in cell transformation, and pointed out the direction of disease treatment.
6.Modification of m6 A in human embryonic lung fibroblasts induced by neodymium oxide exposure and its mechanism
Zhao ZHAO ; Jingjing ZHENG ; Mingxuan YANG ; Suhua WANG ; Xuemin SHI ; Shuwen GAO ; Yuhang ZHAO
Journal of Environmental and Occupational Medicine 2023;40(9):1014-1023
Background Occupational and environmental particulate matter may cause fibrosis, accompanied by RNA m6A modification changes. Neodymium oxide (Nd2O3) can cause mouse lung fibrosis, which contains a large number of fibroblasts. Objective To investigate m6A modification of tumor necrosis factor receptor-associated protein 6/nuclear factor-κB (TRAF6/NF-κB) signaling pathway in fibrosis of human embryonic lung fibroblasts induced by Nd2O3, and identify the key m6A modification sites of TRAF6. Methods Designed concentrations of Nd2O3 (0, 1.563, 3.125, 6.25, 12.5, 25, 50, 100, and 200 mg∙L−1) were infected with HELF cells for 24 and 48 h, and cell viability was detected to determine exposure time and dose. Measurements included indicators of fibrosis [hydroxyproline (HYP) and transforming growth factor-β1 (TGF-β1)], m6A methylation level, methyltransferases (METTL3 and METTL14), demethylases (FTO and ALKBH5), reading proteins (YTHDC2 and YTHDF2), fibrosis-associated genes (collagen-І, vimentin, and α-SMA), and proteins related to signaling pathway (TRAF6, NFKB1, P65, and P-P65). The enrichment of m6A in TRAF6 mRNA was measured by methylated RNA immunoprecipitation-quantitative real-time PCR (MeRIP-qPCR). Results The results of cell viability indicated that 6.25, 12.5, 25 mg∙L−1 Nd2O3 and 48 h exposure time were used for subsequent experiments. After 48 h exposure, compared with the control group, the HYP level in the 25 mg∙L−1 Nd2O3 group was increased, and the levels of TGF-β1 in the 6.25, 12.5, and 25 mg∙L−1 Nd2O3 groups were increased (P<0.05); the overall m6A methylation levels of HELF cells in the 12.5 and 25 mg∙L−1 Nd2O3 groups were increased (P<0.05). At mRNA level, compared with the control group, the mRNA expression levels of methyltransferases METTL3 and METTL14 (6.25, 12.5, and 25 mg∙L−1 Nd2O3) were increased (P<0.05); the mRNA expression level of reading protein YTHDF2 (6.25, 12.5, and 25 mg∙L−1 Nd2O3) was increased (P<0.05), while the mRNA expression level of YTHDC2 (25 mg∙L−1 Nd2O3) was decreased (P<0.05); the mRNA expression levels of demethylases FTO (12.5 and 25 mg∙L−1 Nd2O3) and ALKBH5 (25 mg∙L−1 Nd2O3) were decreased (P<0.05); the mRNA expression levels of fibrosis-related genes vimentin, α-SMA, and collagen-Ⅰ (6.25, 12.5, and 25 mg∙L−1 Nd2O3) were increased (P<0.05); the mRNA expression levels of pathway-related genes TRAF6 (25 mg∙L−1 Nd2O3) and NFKB1 (12.5 and 25 mg∙L−1 Nd2O3) were increased (P<0.05). At protein level, compared with the control group, the expression levels of methyltransferases METTL3 (25 mg∙L−1 Nd2O3) and METTL14 (12.5 and 25 mg∙L−1 Nd2O3) were increased (P<0.05); the expression level of reading protein YTHDF2 (12.5 and 25 mg∙L−1 Nd2O3) was increased, while the expression level of YTHDC2 (25 mg∙L−1 Nd2O3) was decreased (P<0.05); the expression level of demethylase FTO (25 mg∙L−1 Nd2O3) was decreased (P<0.05); the expression level of fibrosis-associated protein vimentin was increased at 25 mg∙L−1 Nd2O3, and the expression levels of α-SMA and collagen-Ⅰ were increased at 12.5 and 25 mg∙L−1 Nd2O3 (P<0.05); the expression levels of TRAF6 and P-P65 were increased at 25 mg∙L−1 Nd2O3 (P<0.05). The MeRIP-qPCR results showed that compared with the control group, the concentrations of m6A in all Nd2O3 groups were significantly increased (P<0.05). Conclusions Upon exposure of HELF cells to Nd2O3, the alterations in fibrosis-related indexes increase the expression of some m6A methylases and decrease the expression of demethylases, thereby increasing the m6A methylase level, and may promote the progression of fibrosis by activating the TRAF6/NF-κB signaling pathway.
7.Quality evaluation of health education guidelines for discharged recipients with solid organ transplantation
Jing SUN ; Shujing HU ; Dongxia YANG ; Xingyu QI ; Xuemin ZHAO ; Hongxia LIU
Chinese Journal of Modern Nursing 2023;29(4):445-453
Objective:To evaluate the guidelines on discharged health education for solid organ transplant recipients at home and abroad, analyze the characteristics of each guideline, so as to provide reference for the development of health education for organ transplantation in China.Methods:This was a guideline quality evaluation study. The guidelines on health education for discharged recipients with solid organ transplantation were searched on the websites of clinical practice guidelines, the websites of transplantation professional associations, and Chinese and English databases at home and abroad through computers. The search time limit was from January 1, 2011 to January 1, 2022. The quality of guidelines that met the inclusion and exclusion criteria was evaluated using the Appraisal of Guidelines for Research and Evaluation Ⅱ (AGREE Ⅱ) .Results:A total of 8 guidelines were included. The overall quality evaluation of the guideline was Grade A ( n=2) and Grade B ( n=6) . In terms of standardized scores in six areas of quality evaluation, the average values of scope and purpose, stakeholder involvement, rigour of development, clarity and presentation, applicability as well as editorial independence were 87.62% (70.37%-100.00%) , 75.46% (44.44%-97.22%) , 66.54% (43.75%-93.06%) , 90.16% (77.78%-96.30%) , 48.18% (20.83%-68.75%) and 74.13% (8.30%-97.22%) , respectively. The recommendations of the guidelines covered 9 aspects: team composition and support services, drug management, infection prevention, complication management, diet and nutrition, daily life and social reintegration, contraception and reproduction, psychological guidance and follow-up review. Conclusions:The development of guidelines for different types of solid organ transplantation varies. The overall quality of the guidelines needs to be improved and the content needs to be refined. In the future, we can learn from foreign high-quality guidelines to carry out localization practice, so as to build a health education related guideline for discharge of solid organ transplantation that is suitable for China's national conditions as soon as possible.
8.Changes of m6A modification in arsenic-induced oxidative stress of human embryonic lung fibroblasts
Jingjing ZHENG ; Zhao ZHAO ; Jiajing ZHANG ; Suhua WANG ; Ning BU ; Xuemin SHI ; Yuhang ZHAO
Journal of Environmental and Occupational Medicine 2022;39(5):499-505
Background Arsenic can be toxic to human by triggering oxidative stress, which is companied by epigenetic modifications. Objective To investigate the modification of N6-methyladenosine (m6A) in human embryonic lung fibroblasts (HELF) during oxidative stress induced by sodium arsenite (NaAsO2). Methods HELF cells were treated by designed concentrations of NaAsO2 (0, 2.5, 5, 10, and 20 μmol·L−1) for 48 h. Cell viability was detected by 3-(4,5-dimethylthia zol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium (MTS) method; the activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) as well as the content of malondialdehyde (MDA) were detected with corresponding kits; the level of m6A methylation in total RNA was detected by enzyme-linked immunosorbent assay; the mRNA expressions of m6A modified enzymes were detected by real-time fluorescence quantitative PCR, including methyltransferase-like 3 (METTL3), methyltransferase-like 14 (METTL14), Wilms' tumor 1-associated protein (WTAP), fat mass and obesity-associated protein (FTO), alkB family of Fe(II)/α-ketoglutarate-dependent dioxygenases 5 (ALKBH5), YTH domain containing protein 2 (YTHDC2), YTH domain family protein 2 (YTHDF2), and YTH domain family protein 3 (YTHDF3); the protein expressions of METTL3, FTO, YTHDC2, YTHDF3, and nuclear factor erythroid 2-related factor 2 (NRF2) were detected by Western blotting. The enrichment of m6A in NRF2 mRNA was detected by RNA methylated immunoprecipitation combined with real-time fluorescence quantitative PCR (MeRIP-qPCR). Results After the 0, 2.5, 5, 10, and 20 μmol·L−1 NaAsO2 treatment, the MTS results showed that compared with the control group, the cell viability of the 20 μmol·L−1 group decreased to 84% (P<0.05). The colorimetry results showed that compared with the control group, the activities of T-SOD in the 10 and 20 μmol·L−1 groups decreased (P<0.05); the activities of GSH-Px in the 2.5 and 10 μmol·L−1 groups decreased (P<0.05); the contents of MDA in the 10 and 20 μmol·L−1 groups increased. The results of enzyme-linked immunosorbent assay showed that the overall m6A methylation levels in the 0, 2.5, 5, 10, and 20 μmol·L−1 groups were (0.193 ± 0.023)%, (0.247 ± 0.021)%, (0.253 ± 0.006)%, (0.233 ± 0.006)%, and (0.262 ± 0.010)%, respectively, and compared with the control group, the m6A methylation levels in all the NaAsO2 treated groups increased (P<0.05). The real-time fluorescence quantitative PCR results showed that compared with the control group, the mRNA relative expression level of METTL3 decreased in the 2.5, 10, and 20 μmol·L−1 groups (P<0.05); the mRNA relative expression level of FTO decreased in the 20 μmol·L−1 group; the mRNA relative expression level of YTHDC2 increased in the 10 and 20 μmol·L−1 groups (P<0.05); the mRNA relative expression level of YTHDF3 increased in the 2.5, 10, and 20 μmol·L−1 groups (P<0.05). The Western blotting results showed that compared with the control group, the relative protein expression of METTL3 decreased in the 10 and 20 μmol·L−1 groups; the relative protein expression of FTO decreased in the 5 and 20 μmol·L−1 groups; the relative protein expression of YTHDC2 decreased in the 20 μmol·L−1 group (P<0.05); the relative nuclear protein expression of NRF2 decreased in the 10 and 20 μmol·L−1 groups (P<0.05). The MeRIP-qPCR results showed that m6A enrichment was significantly increased in the 20 μmol·L−1 NaAsO2 exposure group compared with the control group (P<0.05). After over-expression of FTO, the mRNA and protein relative expression levels of FTO and the relative expression level of nuclear protein of NRF2 in the FTO group were higher than those in the control group (P<0.05); the mRNA and protein relative expression levels of FTO in the NaAsO2 + FTO group and the nuclear protein expression level of NRF2 were higher than those in the NaAsO2 group (P<0.05). Conclusion In the process of oxidative stress induced by NaAsO2, m6A methylation level, m6A modified enzymes, m6A modification of NRF2 mRNA, and NRF2 expression could change in HELF cells.
9.Clinical characteristics of 272 437 patients with different histopathological subtypes of primary esophageal malignant tumors
Lidong WANG ; Liuyu LI ; Xin SONG ; Xueke ZHAO ; Fuyou ZHOU ; Ruihua XU ; Zhicai LIU ; Aili LI ; Jilin LI ; Xianzeng WANG ; Liguo ZHANG ; Fangheng ZHU ; Xuemin LI ; Weixing ZHAO ; Guizhou GUO ; Wenjun GAO ; Xiumin LI ; Lixin WAN ; Jianwei KU ; Quanxiao XU ; Fuguo ZHU ; Aifang JI ; Huixiang LI ; Jingli REN ; Shengli ZHOU ; Peinan CHEN ; Qide BAO ; Shegan GAO ; Haijun YANG ; Jinchang WEI ; Weimin MAO ; Zhanqiang HAN ; Zhiwei CHANG ; Yingfa ZHOU ; Xuena HAN ; Wenli HAN ; Lingling LEI ; Zongmin FAN ; Ran WANG ; Yuanze YANG ; Jiajia JI ; Yao CHEN ; Zhiqiang LI ; Jingfeng HU ; Lin SUN ; Yajie CHEN ; Helin BAI ; Duo YOU
Chinese Journal of Internal Medicine 2022;61(9):1023-1030
Objective:To characterize the histopathological subtypes and their clinicopathological parameters of gender and onset age by common, rare and sparse primary esophageal malignant tumors (PEMT).Methods:A total of 272 437 patients with PEMT were enrolled in this study, and all of the patients were received radical surgery. The clinicopathological information of the patients was obtained from the database established by the State Key Laboratory of Esophageal Cancer Prevention & Treatment from September 1973 to December 2020, which included the clinical treatment, pathological diagnosis and follow-up information of esophagus and gastric cardia cancers. All patients were diagnosed and classified by the criteria of esophageal tumor histopathological diagnosis and classification (2019) of the World Health Organization (WHO). The esophageal tumors, which were not included in the WHO classification, were analyzed separately according to the postoperative pathological diagnosis. The χ 2 test was performed by the SPSS 25.0 software on count data, and the test standard α=0.05. Results:A total of 32 histopathological types were identified in the enrolled PEMT patients, of which 10 subtypes were not included in the WHO classification. According to the frequency, PEMT were divided into common (esophageal squamous cell carcinoma, ESCC, accounting for 97.1%), rare (esophageal adenocarcinoma, EAC, accounting for 2.3%) and sparse (mainly esophageal small cell carcinoma, malignant melanoma, etc., accounting for 0.6%). All the common, rare, and sparse types occurred predominantly in male patients, and the gender difference of rare type was most significant (EAC, male∶ female, 2.67∶1), followed with common type (ESCC, male∶ female, 1.78∶1) and sparse type (male∶ female, 1.71∶1). The common type (ESCC) mainly occurred in the middle thoracic segment (65.2%), while the rare type (EAC) mainly occurred in the lower thoracic segment (56.8%). Among the sparse type, malignant melanoma and malignant fibrous histiocytoma were both predominantly located in the lower thoracic segment (51.7%, 66.7%), and the others were mainly in the middle thoracic segment.Conclusion:ESCC is the most common type among the 32 histopathological types of PEMT, followed by EAC as the rare type, and esophageal small cell carcinoma and malignant melanoma as the major sparse type, and all of which are mainly occur in male patients. The common type of ESCC mainly occur in the middle thoracic segment, while the rare type of EAC mainly in the lower thoracic segment. The mainly sparse type of malignant melanoma and malignant fibrous histiocytoma predominately occur in the lower thoracic segment, and the remaining sparse types mainly occur in the middle thoracic segment.
10.Feasibility of application of deformable image registration to the dosimetry assessment of fractionated brachytherapy for cervical cancer
Qiang ZHAO ; Xiangyang WU ; Xiaobin CHANG ; Tao FENG ; Di YANG ; Ximei QU ; Xuemin WANG ; Jia DENG
Chinese Journal of Radiological Medicine and Protection 2022;42(3):204-209
Objective:To study the differences in the cumulative dose between deformable image registration (DIR) and simple dose-volume histogram (DVH) summation in the fractionated brachytherapy of cervical cancer, and to analyze the feasibility of the application of DIR in the dosimetry assessment of targets and organs-at-risk (OARs) in the brachytherapy.Methods:A retrospective analysis was conducted for 13 cases with primary cervical cancer treated with four fractions of interstitial brachytherapy guided by CT images. The four CT images of each cases were registered using an intensity-based DIR. Then, the cumulative doses (the D2 cm 3, D1 cm 3, and D0.1 cm 3 of the bladder, rectum, intestine, and colon and the D90for targets) after DIR were calculated and compared to those obtained using simple DVH summation. Afterward, the correlation between the dose difference and dice similarity coefficient (DSC) was analyzed. With the dose difference (the remaining dose of OARs caused by the DIR) as limits, a new plan was made for the latest CT to calculate the dose increase to targets. Results:Compared to simple DVH summation, DIR allowed the cumulative doses of the D2 cm 3 and D1 cm 3 of bladder to be decreased by (2.47±1.92) and (2.82±2.73) Gy, respectively on average ( t=-3.65, -2.93, P < 0.05), those of the D2 cm 3, D1 cm 3, and D0.1 cm 3 of rectum to be decreased by (2.05 ± 1.61) Gy, (1.51 ± 1.58), and (3.21 ± 2.50) Gy, respectively on average ( t=-4.02, -3.02, -4.06, P < 0.05), and those of the D2 cm 3, D1 cm 3, and D0.1 cm 3 to be decreased by (1.42 ± 0.99), (1.55 ± 1.28) Gy, and (2.43 ± 1.95) Gy, respectively on average ( t=-3.52, -2.96, -3.06, P < 0.05). There was no significant statistical difference in the D90 of targets, the D0.1 cm 3 of the bladder, and the D2 cm 3, D1 cm 3, D0.1 cm 3 of the colon ( P > 0.05) between both methods, and there was no distinct correlation between DSC and dose difference ( P > 0.05). The DIR increased the dose to targets, with a median value of 150 cGy. However, the accuracy of the DIR should be improved. Conclusions:In clinical practice of multiple fractions of brachytherapy for cervical cancer, it′s still recommended to adopt the simple dose summation method to assess the doses to targets and OARs.

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