1.Quality re-optimization and assessment of radiotherapy plan for rectal cancer
Lin HUANG ; Yimei LIU ; Meining CHEN ; Shaomin HUANG ; Xiaowu DENG ; Yinglin PENG ; Yu ZHANG
Chinese Journal of Medical Physics 2024;41(2):133-138
Objective To evaluate the quality of treatment planning(TP)and re-optimization planning(RP)of radiotherapy for rectal cancer using PlanIQ software,thereby providing methods and tools for the screening and optimization of radiotherapy plans.Methods Twenty patients with rectal cancer who received radiotherapy were selected retrospectively,with 10 cases of intensity-modulated radiotherapy(IMRT)and 10 of volumetric modulated arc therapy(VMAT).(1)TP:IMRT plan involved 5-field irradiation,and VMAT plan involved two 360°arcs.The prescription doses were 50 Gy/25 f for PTV1 and 45 Gy/25 f for PTV2.All plans underwent direct machine parameter optimization and required 95%isodose lines to cover 100%of the target volume.Organs-at-risk(OAR)were limited by reference to tolerated dose standards.After the planning was completed,the plans were reviewed and confirmed by a physician,and the treatment was implemented after dose verification.(2)RP:a physicist with 10 years of experience re-optimized the 20 TP plans,with the irradiation technique and field setting unchanged.The re-optimization involved adjusting planning conditions and parameters based on individual experience until the dose to OAR was minimized while without affecting PTV coverage.The quality of TP plans and RP plans were quantitatively evaluated using PlanIQ software.Non-parametric Wilcoxon signed rank test was performed for dose-volume histogram parameters and plan quality index between two groups.Results The dose-volume histogram parameters in RP plans were superior to those in TP plans,and the differences in the Dmax of PTV1,the V45 Gy and Dmax of small intestine,and the V45 Gy of colon were statistically significant(P<0.05).The quality scores of RP plans for IMRT group,VMAT group and all patients were significantly higher than those of TP plans(P<0.05),with plan quality index of 88.55±3.35 vs 86.61±4.63(P=0.005),89.72±3.15 vs 87.21±3.04(P=0.028),and 89.14±3.22 vs 86.91±3.22(P=0.001),respectively.Conclusion RP can further improve the quality of radiotherapy plan for rectal cancer.PlanIQ software serves as an effective tool for quality control and screening of radiotherapy planning.
2.Comparison of interobserver variations in delineation of target volumes and organs-at-risk for intensity-modulated radiotherapy of nasopharyngeal carcinoma among physicians from different levels of cancer centers
Meining CHEN ; Yimei LIU ; Yinglin PENG ; Qiuying XIE ; Jinping SHI ; Rong HUANG ; Chong ZHAO ; Xiaowu DENG ; Meijuan ZHOU
Chinese Journal of Medical Physics 2024;41(3):265-272
Objective To assess inter-observer variations(IOV)in the delineation of target volumes and organs-at-risk(OAR)for intensity-modulated radiotherapy(IMRT)of nasopharyngeal carcinoma(NPC)among physicians from different levels of cancer centers,thereby providing a reference for quality control in multi-center clinical trials.Methods Twelve patients with NPC of different TMN stages were randomly selected.Three physicians from the same municipal cancer center manually delineated the target volume(GTVnx)and OAR for each patient.The manually modified and confirmed target volume(GTVnx)and OAR delineation structures by radiotherapy experts from the regional cancer center were used as the standard delineation.The absolute volume difference ratio(△V_diff),maximum/minimum volume ratio(MMR),coefficient of variation(CV),and Dice similarity coefficient(DSC)were used to compare the differences in organ delineation among physicians from different levels of cancer centers and among the 3 physicians from the same municipal cancer center.Furthermore,the IOV of GTVnx and OAR among physicians from different levels cancer centers were compared across different TMN stages.Results Significant differences in the delineation of GTVnx were observed among physicians from different levels of cancer centers.Among the 3 physicians,the maximum values of △V_diff,MMR,and CV were 97.23%±83.45%,2.19±0.75,and 0.31±0.14,respectively,with an average DSC of less than 0.7.Additionally,there were considerable differences in the delineation of small-volume OAR such as the left and right optic nerves,chiasm,and pituitary,with average MMR>2.8,CV>0.37,and DSC<0.51.However,relatively smaller differences were observed in the delineation of large-volume OAR such as the brainstem,spinal cord,left and right eyeballs,and left and right mandible,with average△V_diff<42%,MMR<1.55,and DSC>0.7.Compared with the differences among physicians from different levels cancer centers,the differences among the 3 physicians from the municipal cancer center were slightly reduced.Furthermore,there were also differences in the delineation of target volumes for NPC among physicians from different levels cancer centers,depending on the staging of the disease.Compared with the delineation of target volumes for earlier stage patients(stages I or II),the differences among physicians in the delineation of target volumes for advanced stage patients(stages III or IV)were smaller,with average △V_diff and DSC of 98.31%±67.36%vs 69.38%±72.61%(P<0.05)and 0.55±0.08 vs 0.72±0.12(P<0.05),respectively.Conclusion There are differences in the delineation of GTVnx and OAR in radiation therapy for NPC among physicians from different levels of cancer centers,especially in the delineation of target volume(GTVnx)and small-volume OAR for early-stage patients.To ensure the accuracy of multicenter clinical trials,it is recommended to provide unified training to physicians from different levels of cancer centers and review their delineation results to reduce the effect of differences on treatment outcomes.
3.Machine learning-based prediction of long-term mortality in patients with atrial fibrillation and coronary heart disease aged 60 years and over
Min DONG ; Tong ZOU ; Bingfeng PENG ; Jiyun SHI ; Lei XU ; Zuowei PEI ; Yimei QU ; Meihui ZHANG ; Fang WANG ; Jiefu YANG
Chinese Journal of Geriatrics 2022;41(7):804-810
Objective:To establish a long-term mortality rate prediction model for patients aged 60 years and over with atrial fibrillation and coronary heart disease using the machine learning method, and identify the corresponding risk factors of mortality.Methods:In this retrospective cohort study, a total of 329(11 cases lost of follow-up)patients with 183 males(55.6%)and 146 females(44.4%), aged(77.8±7.3)years, and 142 patients aged 80 years or older(43.2%)were selected in our hospitals from January 2013 to March 2015.And their clinical data on atrial fibrillation and coronary heart disease were analyzed.They were divided into the death group(151 cases)and the survival group(167 cases)according to the survival outcome.In addition, 60 patients aged 60 years and over admitted to our hospitals from April to July 2015 with atrial fibrillation and coronary heart disease were selected as external data validation set.The clinical data included age, gender, body mass index, diagnosis, co-morbidity, laboratory indicators, electrocardiogram, echocardiogram, treatment data.These patients were followed up for at least 6 years, and the main adverse cardiovascular and cerebrovascular events(MACCE), including death, were recorded.Finally, the data of the enrolled patients were randomly divided into the training set and the test set according to the ratio of 9∶1, Different models were established to predict the long-term mortality of patients with atrial fibrillation and coronary heart disease by machine learning algorithm.The optimal model was established by substituting external data(60 cases)into the model for verification and comparison.The top 20 risk factors for mortality were determined by Shapley additive explanation(SHAP)algorithm.Results:A total of 329 hospitalized patients were included in this study, the overall median follow-up time was 77.0 months(95% CI: 54.0~84.0), 11 cases lost during follow-up(3.3%), and 151 cases died(45.9%). The analysis found that the areas under the ROC curve for a support vector machine(SVM)model, k-Nearest Neighbor(KNN)model, decision tree model, random forest model, ADABoost model, XGBoost model and logistic regression model were 0.76, 0.75, 0.75, 0.91, 0.86, 0.85 and 0.81, respectively.The random forest model had the highest prediction efficiency, with the accuracy of 0.789 and F1 value of 0.806, which was better than the logistic regression model[the Area Under Receiver Operating Characteristic Curve(AUC): 0.91 vs.0.81, P<0.05]. D-dimer, age, number of MACCE, left ventricular ejection fraction, serum albumin level, anemia, New York Heart Association(NYHA)grade, history of old myocardial infarction, estimated glomerular filtration rate(eGFR)and resting heart rate were important risk factors for predicting long-term mortality. Conclusions:The random forest model based on machine learning method can predict the long-term mortality of patients with atrial fibrillation and coronary heart disease aged 60 years and over, have a good identification ability.Its accuracy is higher than that of the traditional Logistic regression model.Reducing the long-term mortality and improving the long-term outcomes can be achieved by intervening on D-dimer levels, correcting hypoproteinemia and anemia, improving cardiac function and controlling resting ventricular rates.
4.Clinical application effect of modified nasopharyngeal swab sampling for 2019 novel coronavirus nucleic acid detection
Siyuan MA ; Yimei LUO ; Tianyu HU ; Zaichun YOU ; Jianguo SUN ; Shiyong YU ; Zhiqiang YUAN ; Yizhi PENG ; Gaoxing LUO ; Zhi XU
Chinese Journal of Burns 2020;36(8):679-685
Objective:To study the clinical application effect of modified nasopharyngeal swab sampling for 2019 novel coronavirus nucleic acid detection.Methods:This study covered the period from January 14 to March 1, 2020.The supine position method and the protective face screen were used to collect nasopharyngeal swabs from February 24 onwards, before which, the nasopharyngeal swabs were collected by sitting position method. All the patients who were diagnosed with suspected/confirmed 2019 novel coronavirus infection were admitted from February 19 with the nasopharyngeal swabs collected outside the hospital before admission. (1) Thirty-four swabbing operators meeting the inclusion criteria of the study were recruited in this retrospective cohort study. They were grouped according to the collection method of nasopharyngeal swabs. Sixteen operators of Wuhan Taikang Tongji Hospital who applied the supine position method and the protective face screen were included in supine position method+ protective face screen group (15 males and 1 female, aged 34-49 years); 18 operators (12 from the First Affiliated Hospital of Army Medical University (the Third Military Medical University), 1 from Wuhan Jiangxia Mobile Cabin Hospital, 5 from the East District of People′s Hospital of Wuhan University) who applied the traditional sitting position method were included in sitting position method group (2 males and 16 females, aged 25-49 years). In supine position method+ protective face screen group, when collecting sample, the patient lay flat and wore a special protective face screen for nasopharyngeal swab sampling, with neck slightly extending and face turning to the opposite side of the operator about 10°. The self-designed questionnaire was used to investigate the cooperation, the incidence of nausea, coughing, sneezing, and struggling of patients evaluated by the operators, the operation time for a single swab sample, the fear of operation and the perceived exposure risk of operators in the two groups. (2) Sixty-five patients (22 males and 43 females, aged 25-91 years) admitted to Wuhan Taikang Tongji Hospital who successively received the sitting position method and supine position method+ protective face screen for nasopharyngeal swabs sampling and with complete nucleic acid detection results were included. The positive rates of nucleic acid detection by the two sampling methods of nasopharyngeal swabs of the patients were statistically analyzed. (3) Forty-one patients who could express their feelings accurately were selected out of those 65 patients (12 males and 29 females, aged 27-83 years). The comfort of patients in the process of sampling by the two methods was investigated. (4) Thirty-four patients (10 males and 24 females, aged 25-83 years) with two or more consecutive negative results of nucleic acid detection of nasopharyngeal swabs by sitting position method were selected from the above 65 patients. The positive rate of nucleic acid detection of nasopharyngeal swab of patients by supine position method+ protective face screen, i. e. negative to positive rate was statistically analyzed. Data were statistically analyzed with t test, Wilcoxon signed rank test, and chi-square test. Results:(1) Compared with those of sitting position method group, the cooperation score of patients evaluated by the operators in supine position method+ protective face screen group was significantly higher ( Z=-4.928, P<0.01), the incidence of nausea, choking cough, sneezing, and struggling of patients evaluated by the operators, and the fear of operation score and the perceived exposure risk score of operators in supine position method+ protective face screen group were significantly lower ( Z=-5.071, -5.046, -4.095, -4.397, -4.174, -5.049, P<0.01), and the operation time for a single swab sample in supine position method+ protective face screen group was significantly longer ( t=223.17, P<0.01). (2) The positive rate of nucleic acid detection of nasopharyngeal swabs by supine position method+ protective face screen was 60.00% (39/65), which was obviously higher than 41.54% (27/65) by sitting position method ( χ2=4.432, P<0.05). (3) The comfort score of the 41 patients during nasopharyngeal swabs sampling by supine position method+ protective face screen was significantly higher than that by sitting position method ( Z=-5.319, P<0.01). (4) Of the 34 patients with two or more consecutive negative results of nucleic acid detection of nasopharyngeal swabs by sitting position method, the rate of negative to positive of nucleic acid detection was 26.47% (9/34) after sampling by supine position method+ protective face screen. Conclusions:Compared with the traditional sitting position method, detection of 2019 novel coronavirus nucleic acids of nasopharyngeal swabs collected by supine method combined with protective face screen is worth promoting, because of its better comfort of patients, low exposure risk for operators, in addition to reducing in the false negative result to some extent, which may help reduce false recurrence of discharged patients.
5. The clinical observation of serum specific biomarkers in patients with chronic graft-versus-host disease
Ting CHEN ; Xiaoping LI ; Cheng ZHANG ; Peiyan KONG ; Qiangguo GAO ; Lun TANG ; Rui WANG ; Shijie YANG ; Lei GAO ; Yao LIU ; Li GAO ; Yimei FENG ; Jun RAO ; Xiangui PENG ; Xi ZHANG
Chinese Journal of Hematology 2019;40(11):948-952
Objective:
Chronic graft-versus-host disease (cGVHD) is a major long-term complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . It is important to study the changes of serum biomarkers expression in patients for early diagnosis and treatment.
Methods:
The expression levels of five serum protein markers (IL-1b, IL-16, CXCL9, CCL19, CCL17) in patients with or without cGVHD after allo-HSCT were detected by liquid suspension microarray.
Results:
Compared with the control group without cGVHD, the expression levels of CXCL9 and CCL17 in serum of patients with cGVHD were significantly increased (
7.The expression of immune regulatory factors in thymoma with myasthenia gravis
Hui ZHANG ; Peng ZHANG ; Yimei LIU ; Yuan CHEN ; Xin LI ; Peng LYU ; Yuanguo WANG
Chinese Journal of Thoracic and Cardiovascular Surgery 2017;33(3):155-159
Objective To investigate the expression of Aire,Foxp3,AchR and other immune factors in human thymoma tissue and plasma and explore their role in myasthenia gravis with thymoma.Methods T lymphocyte subsets,immunoglobulin and other immune factors in plasma were compared,and the Expression of Aire,Foxp3 and AchR were examined in thymoma by reverse transcriptional polymerase chain reaction and immunohistochemical staining,and the results were analyzed by SPSS statistics software.Results The ratio of CD4 + to CD8 + T lymphocyte was much higher in plasma,while the expressions of Aire,Foxp3 and AchR at mRNA and protein level were much lower in thymoma patients with myasthenia gravis,and related to Ossermann subtype,WHO subgroup and Masaoka stage.The differences were statistically significant (P < 0.05).Conclusion The ratio of CD4 + to CD8 + T lymphocyte and the abnormal expressions of Aire and Foxp3could used as an indicator of immune state in thymoma patient with myasthenia gravis and play an important role in the development of thymoma with myasthenia gravis,but the mechanism is indefinite.
8.Research progress in benchmark dose in risk assessment of long-team exposure toxicity
Hui PENG ; Qiaofang LI ; Jian YIN ; Tingfen ZHANG ; Jiabin GUO ; Yimei WANG ; Shuangqing PENG
Military Medical Sciences 2016;40(10):851-855
The purpose of risk assessment is to evaluate the permissible exposure level under specific risk factors.To extrapolate the human acceptable daily intake (ADI) and/or reference dose (RfD), the traditional method uses the no-observed-adverse-effect level ( NOAEL ) to quantify toxicity after being divided by uncertainty factor.There are many limitations with NOAEL method in safety evaluation,for it relies too much on experimental design.Benchmark dose ( BMD) approach is a more reliable method with many advantages.BMD approach and its analysis software, the advantages of BMD over NOAEL, the application and methodological perfection in risk assessment of long-team exposure toxicity are presented in this review.
9.Establishment of normal reference ranges for clinical pathology indexes of Beagle dogs in GLP system
Li JIA ; Yimei WANG ; Lijun ZHANG ; Lizhong LI ; Shuangqing PENG
Military Medical Sciences 2016;40(2):147-149
Objective To establish the normal reference ranges of clinical pathology for Beagle dogs in the Good Laboratory Practice ( GLP ) system.Method Sixteen biochemical indexes , seventeen hematological indexs and three coagulation function indexes of 117 Beagle dogs were detected , and the mean value of each index and the normal reference ranges were calculated and compared .Results Only alkaline phosphatase ( ALP ) from the biochemical items was significantly different between males and females (P<0.01),which was higher among males than among females .Three in-dexes of hematology were significantly different between males and females (P<0.01),with red blood cell(RBC), hemo-globin(HGB)and hematocrit(HCT)lower among males than among females.The coagulation function items were not signif-icantly different between the two sexes .Conclusion Some indexes of clinical pathology were significantly different between males and females , which should be considered during statistic analysis on toxicity .Our study has established the normal reference range of clinical pathology for Beagle dogs in the GLP system , which provides reference for toxicity tests .
10.Repeated dose toxicity of Tangwang Mingmu granules in Sprague-Dawley rats
Hui PENG ; Zengming ZHAO ; Li JIA ; Yulei SHU ; Jun HE ; Tingfen ZHANG ; Lizhong LI ; Xiushu HE ; Ye LIU ; Zenglin LIAN ; Jun ZHAO ; Yimei WANG ; Shuangqing PENG
Military Medical Sciences 2016;40(12):978-983
Objective To observe toxic symptoms and signs , toxic damage extents and reversibility in rats after oral administration of Tangwang Mingmu granules .Methods Four dose groups with 40 rats in each group were designed in this study, including control group fed with distilled water and three groups at different dosages of the test drug .Tangwang Mingmu granules were orally administered to SD rats at the dosage of 8.4, 4.2 and 2.1 g/kg for 3 weeks and 14.0, 8.4 and 4.2 g/kg for 23 weeks, for 26 consecutive weeks .The general state of the rats was observed every day , while body mass and food consumption were calculated once a week .Halfway through and at the end of the administration (13 and 26 weeks) and after four weeks of recovery, parameters of body mass, hematology, hematological biochemistry, organ/body mass ratio and histopathology were measured .Results Compared with the control group at the same time-point, body mass of male rats in the other three groups was slightly reduced .Food consumption in high and medium dose groups was reduced (P<0.05), MCHC, ALT, TBIL and Na +in high dose group were decreased (P<0.05), TP, ALB and D-BIL were increased (P<0.05), the mean body mass and relative organ weight of thymus in medium dose male rats were decreased (P<0.05), relative organ weight of the liver and kidney in high dose male rats was increased (P<0.05), and focal chronic inflammation to different extent was observed in the liver , kidney and prostate gland .No dose-effect relationship was found in these perturbations that were all within the normal range of animals .No significant drug-related pathological changes were found.Conclusion The NOAEL of Tangwang Mingmu granules is considered to be 14.0 g/kg body mass/day (equal to 50 times the proposed clinical adult dosage ) for the 26-week repeated dose oral toxicity study in male andfemale rats.

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