1.Construction and analysis of machine learning models for preoperative prediction of glioma grading and isocitrate dehydrogenase mutation status
Yuting WANG ; Junle ZHU ; Shuang QIN ; Saifei SUN ; Xin ZHANG ; Qi LÜ
Chinese Journal of Clinical Medicine 2026;33(1):3-15
Objective To construct machine learning models based on preoperative inflammatory and radiological features for the prediction of glioma grading and isocitrate dehydrogenase (IDH) mutation status, and to analyze application values of these models and identify the optimal predictive models. Methods A retrospective analysis was conducted on the data of pathologically confirmed glioma patients admitted to Tongji Hospital Affiliated to Tongji University from March 2019 to March 2023. LASSO regression was used to screen feature variables, and predictive models were constructed based on logistic regression (LR), random forest (RF), support vector machine (SVM), gradient boosting decision tree (XGBoost) and K-nearest neighbor (KNN) algorithms. The model performance was comprehensively evaluated using metrics including discrimination ability, area under the precision-recall curve (AUC), accuracy, F1 score and Brier score. The DeLong test was adopted to compare the AUC values among different models; Friedman rank-sum test was used to determine the overall performance differences of the models, with the Nemenyi test applied for multiple comparison correction. Results In the task of glioma grading prediction, the LR model achieved the highest comprehensive score (0.726), and no significant difference was observed between the LR model and the other four models; age was positively correlated with glioma grading (P=0.003). In the task of IDH mutation status prediction, the XGBoost model obtained the highest comprehensive score (0.832), which was superior to the LR (0.762, P=0.035) and KNN models (0.754, P=0.025), while no statistical differences were found between the XGBoost model and the RF or SVM models. Conclusions The LR model for glioma grading prediction and XGBoost model for IDH mutation prediction constructed based on a task-oriented strategy achieve a favorable interpretability while ensuring optimized performance, thereby providing reliable decision support for the individualized diagnosis and treatment of glioma.
2.Trends in global burden due to visceral leishmaniasis from 1990 to 2021 and projections up to 2035
Guobing YANG ; Aiwei HE ; Yongjun LI ; Shan LÜ ; Muxin CHEN ; Liguang TIAN ; Qin LIU ; Lei DUAN ; Yan LU ; Jian YANG ; Shizhu LI ; Xiaonong ZHOU ; Jichun WANG ; Shunxian ZHANG
Chinese Journal of Schistosomiasis Control 2025;37(1):35-43
Objective To investigate the global burden of visceral leishmaniasis (VL) from 1990 to 2021 and predict the trends in the burden of VL from 2022 to 2035, so as to provide insights into global VL prevention and control. Methods The global age-standardized incidence, prevalence, mortality and disability-adjusted life years (DALYs) rates of VL and their 95% uncertainty intervals (UI) were captured from the Global Burden of Disease Study 2021 (GBD 2021) data resources. The trends in the global burden of VL were evaluated with average annual percent change (AAPC) and 95% confidence interval (CI) from 1990 to 2021, and gender-, age-, country-, geographical area- and socio-demographic index (SDI)-stratified burdens of VL were analyzed. The trends in the global burden of VL were projected with a Bayesian age-period-cohort (BAPC) model from 2022 to 2035, and the associations of age-standardized incidence, prevalence, mortality, and DALYs rates of VL with SDI levels were examined with a smoothing spline model. Results The global age-standardized incidence [AAPC = -0.25%, 95% CI: (-0.25%, -0.24%)], prevalence [AAPC = -0.06%, 95% CI: (-0.06%, -0.06%)], mortality [AAPC = -0.25%, 95% CI: (-0.25%, -0.24%)] and DALYs rates of VL [AAPC = -2.38%, 95% CI: (-2.44%, -2.33%)] all appeared a tendency towards a decline from 1990 to 2021, and the highest age-standardized incidence [2.55/105, 95% UI: (1.49/105, 4.07/105)], prevalence [0.64/105, 95% UI: (0.37/105, 1.02/105)], mortality [0.51/105, 95% UI: (0, 1.80/105)] and DALYs rates of VL [33.81/105, 95% UI: (0.06/105, 124.09/105)] were seen in tropical Latin America in 2021. The global age-standardized incidence and prevalence of VL were both higher among men [0.57/105, 95% UI: (0.45/105, 0.72/105); 0.14/105, 95% UI: (0.11/105, 0.18/105)] than among women [0.27/105, 95% UI: (0.21/105, 0.33/105); 0.06/105, 95% UI: (0.05/105, 0.08/105)], and the highest mortality of VL was found among children under 5 years of age [0.24/105, 95% UI: (0.08/105, 0.66/105)]. The age-standardized incidence (r = -0.483, P < 0.001), prevalence (r = -0.483, P < 0.001), mortality (r = -0.511, P < 0.001) and DALYs rates of VL (r = -0.514, P < 0.001) correlated negatively with SDI levels from 1990 to 2021. In addition, the global burden of VL was projected with the BAPC model to appear a tendency towards a decline from 2022 to 2035, and the age-standardized incidence, prevalence, mortality and DALYs rates were projected to be reduced to 0.11/105, 0.03/105, 0.02/105 and 1.44/105 in 2035, respectively. Conclusions Although the global burden of VL appeared an overall tendency towards a decline from 1990 to 2021, the burden of VL showed a tendency towards a rise in Central Asia and western sub-Saharan African areas. The age-standardized incidence and prevalence rates of VL were relatively higher among men, and the age-standardized mortality of VL was relatively higher among children under 5 years of age. The global burden of VL was projected to continue to decline from 2022 to 2035.
3.Progress in role of P2X4R in neuropathic pain caused by peripheral nerve injury
Yan WANG ; Yahui WANG ; Yan WANG ; Fei PEI ; Lijie LÜ ; Tianyi LI ; Shujin WANG ; Huan QIN
Chinese Journal of Pathophysiology 2025;41(10):2023-2029
In recent years,there has been a significant rise in the incidence of peripheral nerve injury(PNI),highlighting the urgent need for effective treatment strategies.The inflammation and pain hypersensitivity associated with PNI greatly diminish patients'quality of life.Although there are promising treatment approaches for nerve injury,the com-plex pathological mechanisms underlying neuropathic pain caused by PNI present significant challenges for clinical manage-ment.Extensive research has established that the development of neuropathic pain is closely linked to nerve conduction and related signaling molecules.Among these,P2X4 receptor(P2X4R),an ATP-dependent ion channel,is involved in nerve signal transmission and associated pathways-plays a crucial role in the progression of neuropathic pain.This article offers a comprehensive overview of the function and distribution of P2X4R,investigates its pathological mechanisms in PNI-induced neuropathic pain,and elucidates its relationship with peripheral neuropathic pain disorders.Through this explo-ration,we aim to provide valuable insights that could inform the development of novel clinical strategies for pain management.
4.Exploring alterations in white matter fiber tracts of Parkinson's disease patients via automated fiber quantification method
Ru TONG ; Sai WANG ; Hongze LÜ ; Kun QIN ; Yuxi WANG ; Pengyu ZHU ; Wen CHEN
Journal of Practical Radiology 2025;41(10):1604-1608
Objective To explore the characteristic changes in white matter microstructure in Parkinson's disease(PD)patients via automated fiber quantification(AFQ)technology,providing a basis for the identification and diagnosis of PD,and to analyze the feasibility of combining the AFQ method with support vector machine(SVM)in the diagnosis of PD.Methods Forty patients with primary PD(PD group)and 20 healthy controls(HC)(HC group)were prospectively selected.The AFQ technology was applied for white matter fiber tract analysis.Statistical analyses were performed using FSL(v6.0)software and SPSS 27.0 software.Independent-sample t-tests were conducted for comparisons between groups in AFQ analysis.The AFQ method was used to analyze the relationship between diffusion tensor imaging(DTI)parameters and Montreal Cognitive Assessment(MoCA)scores.Results(1)The results of AFQ analysis revealed that compared with the HC group,the PD group exhibited significantly lower fractional anisotropy(FA)values in the right cingulum bundle,left cingulum bundle hippocampus,and left uncinate fasciculus,with no differences in the FA values of the remaining 17 fiber tracts.Moreover,PD group demonstrated higher mean diffusivity(MD)values in the left cingulum bundle,left cingulum bundle hippocampus,left inferior frontal occipital fasciculus,left inferior longitudinal fasciculus,left superior longitudinal fasciculus,and left uncinate fasciculus.These differences were statistically significant(P<0.05),while no significant differences were found in the MD values of the remaining 14 fiber tracts.Furthermore,the MD values of the left inferior frontal occipital fasciculus,and left inferior longitudinal fasciculus were negatively correlated with the MoCA scores.(2)The classification results of SVM showed that the best results were achieved when combining the differential nodes of FA and MD as classification features,with an area under the curve(AUC)of 0.922,an accuracy of 84.81%,a sensitivity of 87.50%,and a specificity of 82.05%.Conclusion The DTI parameters in PD patients can serve as potential biomarkers for diagnosis.The AFQ methods provides an effective approach for detecting alterations white matter tract integrity,offering important insights for the identification and diagnosis of PD.The best results are achieved when combining the differential nodes of FA and MD as classification features.
5.Chemical constituents from the sticks and leaves of Croton cascarilloides and their biological activities
Yu-jie LÜ ; Hui-qin CHEN ; Hao WANG ; Jing-zhe YUAN ; Wen-li MEI ; Shou-bai LIU ; Hao-fu DAI
Chinese Traditional Patent Medicine 2025;47(7):2249-2254
AIM To study the chemical constituents from the sticks and leaves of Croton cascarilloides Raeusch.and their biological activities.METHODS The 95%ethanol extract from the sticks and leaves of C.cascarilloides was isolated and purified by MCI,silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.LPS-induced NO RAW264.7 cell model induced by LPS was used to evaluate its anti-inflammatory activity in vitro.GES-1 injury model induced by taurocholic acid was used to screen the gastric mucosal protection activity.RESULTS Fourteen compounds were isolated and identified as bullatantriol(1),(-)-boscialin(2),(+)-dehydrovomifoliol(3),3-(hydroxylacetyl)-indole(4),pinoresinol(5),3,7-dimethyl-octa-1,7-diene-3,6-ol(6),(+)-syringaresinol(7),curcasinlignan B(8),cleomiscosin C(9),cleomiscosinD(10),2,6-dimethyl-octa-1,7-dien-3,6-diol(11),vanillin(12),vanillic acid(13),methyl vanillate(14).Compound 4 had certain anti-inflammatory activity,with IC50 values of 73.62 μmol/L.The protective rates of 25 μmol/L compounds 1-4,6,9-12 and 14 on gastric mucosal epithelial cells were 30.07%,34.18%,23.91%,30.92%,17.51%,19.69%,31.76%,22.46%,30.56%and 14.49%,respectively.CONCLUSION Compounds 1-14 are isolated from this plant for the first time.Compound 4 shows anti-inflammatory activity,1-4,6,9-12 and 14 show different degrees of gastric mucosal epithelial cell protective activity.
6.Clinical observation of point injection at Zusanli(ST36)plus abdominal point application for gastrointestinal dysfunction after laparoscopic surgery
Huanfeng TANG ; Dawei YUAN ; Hua WANG ; Ruxue SU ; Limin QIN ; Jingrui LIU ; Bingtao LÜ ; Jue HONG
Journal of Acupuncture and Tuina Science 2025;23(1):36-42
Objective:To observe the effect of point injection at Zusanli(ST36)plus abdominal point application on gastrointestinal dysfunction after laparoscopic surgery.Methods:A total of 204 patients with gastrointestinal dysfunction after laparoscopic surgery were recruited and divided into four groups using the random number table method,with 51 cases in each group.The control group received conventional postoperative intervention.In addition to the treatment in the control group,the point injection group was given point injection at Zusanli(ST36),the application group was offered abdominal point application,and the integrated group received point injection at Zusanli(ST36)and abdominal point application.The treatment lasted 3 consecutive days in all four groups.The recovery time of gastrointestinal function indicators and the incidence rate of postoperative nausea and vomiting(PONV)were observed and recorded.Before and after treatment,the visual analog scale(VAS)was used to assess abdominal pain intensity,the venous blood type 1 helper T cells/type 2 helper T cells(Th1/Th2)was determined,the serum levels of interleukin(IL)-6 and interferon(IFN)-γ were detected using the enzyme-linked immunosorbent assay,and the plasma levels of motilin and gastrin were measured using radioimmunoassay.Results:Compared to the control group,the first exhaust time,the first defecation time,and the time of restoring fluid diet came earlier in the other three groups(P<0.05)and were earlier in the integrated group than in the point injection and application groups(P<0.05).The point injection,application,and integrated groups had a lower PONV incidence rate than the control group,and the integrated group was lower than the point injection and application groups(P<0.05).The intra-group comparisons showed that the VAS score and the levels of IL-6 and INF-γ decreased after treatment in all four groups(P<0.05);the point injection,application,and integrated groups were lower than the control group(P<0.05),and the integrated group was lower than the point injection and application groups(P<0.05).The intra-group comparisons also demonstrated that the levels of Th1/Th2,motilin,and gastrin increased after the intervention in the four groups(P<0.05);the point injection,application,and integrated groups were higher than the control group(P<0.05),and the integrated group was higher than the point injection and application groups(P<0.05).Conclusion:Point injection at Zusanli(ST36)plus abdominal point application can encourage postoperative exhaust,defecation,and the recovery of diet fluid,alleviate postoperative abdominal pain,reduce PONV,balance Th1/Th2,and regulate the secretion of motilin and gastrin in patients with gastrointestinal dysfunction after laparoscopic surgery.
7.Effects of Heixiaoyao Powder on neuroinflammation in APP/PS1 mice via ATP/P2X7R/NF-κB signaling pathway
Zhi-peng MENG ; Yu-jie LÜ ; Yun-yun HU ; Jiao YANG ; Yi-qin CHEN ; Hu-ping WANG
Chinese Traditional Patent Medicine 2025;47(1):51-57
AIM To investigate the effects of Heixiaoyao Powder on neuroinflammation in APP/PS1 transgenic mice.METHODS The 16-week-old male APP/PS1 transgenic mice were randomly divided into the model group,the BBG group(P2X7R specific antagonist,30 mg/kg)and high,medium and low dose Heixiaoyao Powder groups of(22.10,11.05,5.53 g/kg),in contrast to the male C57BL/6J mice of the same age and the same strain of the blank groups,with 12 mice in each group.When normal saline by gavage was dosed upon the blank group and the model group,and the other groups were treated with corresponding drug by gavage.After 90 days of administration,the mice had their learning and memory ability detected by Morris water maze test;their hippocampal pathological changes observed with HE staining;their MyD88 expression detected by immunofluorescence staining;their hippocampal levels of pro-inflammatory factors(TNF-α,IL-6),anti-inflammatory factors(IL-10),ATP and amyloid protein β(Aβ)detected by ELISA;their hippocampal mRNA expressions of P2X7R,TLR4,MyD88 and NF-κB-P65 detected by RT-qPCR method;and their hippocampal protein expressions of P2X7R,TLR4,MyD88,NF-κB-P65 and p-NF-κB-P65 detected by Western blot.RESULTS Compared with the blank group,the model group demonstrated prolonged escape latency and reduced frequency in crossing platform(P<0.01);decreased number of hippocampal neurons,deranged neurons,and darker cytoplasm staining;increased immunofluorescence expression of hippocampal MyD88(P<0.01);decreased IL-10 level(P<0.01);increased levels of TNF-α,IL-6,ATP and Aβ(P<0.01);increased mRNA and protein expressions ofP2X7R,TLR4 and MyD88(P<0.01),and increased protein expression of p-NF-κB-P65(P<0.01).Compared with the model group,the groups intervened with Heixiaoyao Powder or BBG demonstrated shortened escape latency and increased frequency in crossing platform(P<0.01);more number of neatly arranged hippocampal neurons;increased hippocampal IL-10 level(P<0.01),decreased levels of TNF-α,IL-6,ATP and Aβ(P<0.05,P<0.01);decreased mRNA and protein expressions of P2X7R,TLR4 and MyD88(P<0.05,P<0.01);and decreased protein expression of p-NF-κB-P65(P<0.05,P<0.01).Except the low dose Heixiaoyao Powder group,the other treatment groups shared decreased immunofluorescence expression of MyD88(P<0.05,P<0.01).CONCLUSION Heixiaoyao Powder can significantly improve the learning and memory ability of APP/PS1 model mice,and its mechanism may lie in its function in alleviating cerebral neuroinflammation by reducing the abnormal Aβ aggregation via inhibiting the activation of ATP/P2X7R/NF-κB signaling pathway.
8.Prevalence of Schistosoma japonicum infections in wild rodents in key areas during the elimination phase
Chao LÜ ; Xiaojuan XU ; Jiajia LI ; Ting FENG ; Hai ZHU ; Yifeng LI ; Ling XU ; Zhihong FENG ; Huiwen JIANG ; Xiaoqing ZOU ; Wenjun WEI ; Zhiqiang QIN ; Yang HONG ; Shiqing ZHANG ; Jing XU
Chinese Journal of Schistosomiasis Control 2025;37(5):475-481
Objective To investigate the prevalence of Schistosoma japonicum infections in wild rodents in schistosomiasis-endemic areas of China, so as to provide insights into formulation of technical guidelines for monitoring of and the precise control strategy for S. japonicum infections in wild rodents during the elimination phase. Methods Two administrative villages where schistosomiasis was historically highly prevalent were selected each from Dongzhi County, Anhui Province, and Duchang County, Jiangxi Province as study villages. Wild rodents were captured from study villages with baited traps or cages at night in June and September, 2021. The number of rodents captured was recorded, and the rodent species was characterized based on morphologi-cal characteristics. Liver tissues were sampled from captured rodents for macroscopical observation of the presence of egg granu- lomas, and S. japonicum infection was detected simultaneously using liver tissue homogenate microscopy, examinations of mesenteric tissues for parasites, and modified Kato-Katz thick smear technique (Kato-Katz technique). A positive S. japonicum infection was defined as detection of S. japonicum eggs or adult worms by any of these methods. The rate of wild rodent capture and prevalence of S. japonicum infections in wild rodents were compared in different study villages and at different time periods, and the detection of S. japonicum infections in wild rodents was compared by different assays. Results The overall rate of wild ro- dent capture was 8.28% (237/2 861) in Dongzhi County, and the wild rodent capture rates were 9.24% (133/1 439) and 7.31% (104/1 422) in two study villages (χ2 = 3.503, P = 0.061), and were 8.59% (121/1 409) and 7.99% (116/1 452) in June and September, 2021, respectively (χ2 = 0.337, P = 0.561). The overall rate of wild rodent capture was 3.72% (77/2 072) in Duchang County, and the wild rodent capture rates were 6.91% (67/970) and 0.91% (10/1 102) in two study villages (χ2 = 51.901, P < 0.001), and were 4.13% (39/945) and 3.37% (38/1 127) in June and September, 2021, respectively (χ2 = 0.815, P = 0.365). Rattus norvegicus was the predominant rodent species captured in both counties, accounting for 70.04% (166/237) of all captured wild rodents in Dongzhi County and 88.31% (68/77) in Duchang County. No S. japonicum infection was detected in wild rodents captured in Duchang County. Nevertheless, the overall prevalence of S. japonicum infections was 51.05% (121/237) in wild rodents captured in Dongzhi County, with prevalence rates of 50.38% (67/133) and 51.92% (54/104) in two study villages (χ2 = 0.098, P = 0.755), and 54.31% (63/116) and 47.93% (58/121) in September and June, 2021, respectively (χ2 = 0.964, P = 0.326). Of 237 wild rodents captured in Dongzhi County, there were 140 (59.07%) rodents with visible hepatic egg granulomas, 117 (49.47%) tested positive for S. japonicum eggs by liver tissue homogenate microscopy, 34 (14.35%) tested positive for S. japonicum eggs with Kato-Katz technique; however, no adult S. japonicum worms were detected in mesenteric tissues. In addition, hepatic egg granulomas were found in all wild rodents tested positive for S. japonicum eggs with liver tissue homogenate microscopy. Conclusions The rate of wild rodent capture and prevalence of S. japonicum infection in wild rodents vary greatly in schistosomiasis-endemic areas of China, and the prevalence of S. japonicum infection is slightly higher in wild rodents captured in autumn than in summer. Liver tissue is recommended as the preferred sample for surveillance of S. japonicum infection in wild rodents, and a combination of macroscopical observation of hepatic egg granulomas and liver tissue homogenate microscopy may be a standard method for surveillance of S. japonicum infection in wild rodents.
9.Exploration of the efficacy and safety of indocyanine green in the evaluation and localization of breast cancer surgical margins:a single-center,observational cohort study
Gang LÜ ; Guangqing WANG ; Yan ZHENG ; Qin TANG ; Fei CHEN ; Xudong YU ; Shengqi XU ; Fayang TANG ; Jibiao ZHU
China Oncology 2025;35(8):776-783
Background and purpose:In breast cancer surgery,margin status assessment significantly impacts patient prognosis,with positive margins indicating higher recurrence and metastasis risks.Ensuring complete tumor resection is thus critical for surgical success.Indocyanine green(ICG)has garnered attention for its potential real-time imaging of breast cancer lesions under near-infrared light.This study employed ICG for intraoperative assessment of breast cancer lesion margin status and further explored the possibility of optimizing the safe margin distance surround the lesion in normal breast tissue.Methods:Clinical data of patients admitted to the Department of Thyroid and Breast Surgery,the Fourth Affiliated Hospital of Anhui Medical University(Affiliated Chaohu Hospital),from December 2021 to September 2022 were collected.A retrospective clinical study was conducted on breast cancer patients who were randomly assigned to either the ICG group or the conventional surgery group.Two to three hours before surgery,patients in the ICG group received a peripheral intravenous injection of 0.5 mg/kg ICG.Intraoperative fluorescence imaging was performed on the specimen before and after resection,as well as on the residual cavity.Near-infrared fluorescence imaging equipment was used to quantitatively measure fluorescence intensity of resected lesions at 4 directions(12,3,6,and 9 o'clock)and detect fluorescence in the residual cavity after lesion removal.Specimens were promptly sent to the pathology department for pathological examination,and safety margins of normal breast tissue in the 4 directions were recorded.The Strengthening the Reporting of Observational Studies in Epidemiology(STROBE)checklist was followed for this study.This study was approved by the Ethics Committee of the Fourth Affiliated Hospital of Anhui Medical University(Affiliated Chaohu Hospital)(No.KYXM-202310-46).Results:This study included 50 breast cancer patients,with 24 in the ICG group and 26 in the traditional surgery group.In the ICG group,fluorescence signals were detected at all lesion sites.Specifically,fluorescence density values at the lesion center,margin,and surrounding normal breast tissue were measured as 251.08±10.73,208.08±19.74,and 156.76±16.47,respectively,showing a gradual decrease from center outward with statistically significant differences(P<0.05).Additionally,fluorescence ratios between the lesion center and margin,and center and surrounding normal tissue,were 1.22±0.13 and 1.62±0.19,respectively.After resection,abnormal fluorescence was observed in 2 of 24 cases in the residual cavity,with 1 case being invasive carcinoma with ductal carcinoma in situ and the other normal breast tissue.Ultimately,this study demonstrated that ICG achieved a sensitivity of 95.9%and a specificity of 97.9%in margin assessment.After specimen resection,the safety margins of normal glandular tissue surrounding the lesion were measured.The safety widths for the ICG group and the concurrent breast cancer surgery group were(8.36±6.42)mm and(15.08±4.75)mm,respectively.This difference was statistically significant(P<0.05).Conclusion:ICG is a real-time,efficient,and cost-effective tracer that can be used to determine breast cancer margins,with excellent sensitivity and specificity.For early-stage breast cancer patients who are eligible for breast-conserving surgery,this tracer helps to reduce the amount of healthy breast tissue that is removed around the lesion.
10.Preliminary study for automatically verifying treatment isocenter based on markers
Dongxia LÜ ; Wenhua WANG ; Wei QIN ; Min WANG ; Xiaowei WEI ; Feiyue SHI ; Hongbing JIANG
Chinese Journal of Medical Physics 2025;42(1):1-6
Objective To propose a novel method for verifying the isocenter in radiotherapy based on markers and conduct a preliminary test. Methods A feasibility experiment was conducted on wooden box phantom for radiotherapy resetting. Fifteen groups of displacement data were randomly generated,corresponding to the position deviations of the isocenter in the radiotherapy plan relative to the original isocenter. According to each set of displacement data,with the aid of movable lasers and a CT scanning couch,CT scanning was performed with two sets of markers (3 per set) affixed to the phantom which were corresponding to the original and treatment isocenters,respectively. In the Eclipse treatment planning system,the coordinate data of the original and treatment isocenters were manually verified,and the difference of coordinate data was calculated to obtain the actual displacement value. The treatment isocenter position was finally confirmed by comparing with the actual displacement. In addition,the study attempts to use threshold segmentation algorithm to automatically detect metal markers and obtain coordinate values of the original isocenter on patient-positioned CT images. In the wooden box experiment,the absolute value of the difference between the actual displacement value and the planned displacement value (?d) was used to represent the position accuracy of treatment isocenter,and the deviation value obtained with threshold segmentation algorithm for isocenter detection was ?s. Results The ?d in the X (left-right),Y (superior-inferior) and Z (anterior-superior) directions was (0.83±0.37) mm,0 (0,0.5) mm and (0.45±0.29) mm,respectively. The ?s in the X,Y and Z directions was (0.46±0.22) mm,0 (0,0.5) mm and (0.33±0.29) mm,respectively. The mean values of ?s in 3 directions were all lower than 2 mm,within the range of permissible clinical positioning error. Conclusion The method of automatically verifying treatment isocenter position based on markers is feasible,and the study provides a useful reference for radiotherapy resetting using CT simulator.

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