1.Application of deep learning in automatic segmentation of clinical target volume in brachytherapy after surgery for endometrial carcinoma
Xian XUE ; Kaiyue WANG ; Dazhu LIANG ; Jingjing DING ; Ping JIANG ; Quanfu SUN ; Jinsheng CHENG ; Xiangkun DAI ; Xiaosha FU ; Jingyang ZHU ; Fugen ZHOU
Chinese Journal of Radiological Health 2024;33(4):376-383
Objective To evaluate the application of three deep learning algorithms in automatic segmentation of clinical target volumes (CTVs) in high-dose-rate brachytherapy after surgery for endometrial carcinoma. Methods A dataset comprising computed tomography scans from 306 post-surgery patients with endometrial carcinoma was divided into three subsets: 246 cases for training, 30 cases for validation, and 30 cases for testing. Three deep convolutional neural network models, 3D U-Net, 3D Res U-Net, and V-Net, were compared for CTV segmentation. Several commonly used quantitative metrics were employed, i.e., Dice similarity coefficient, Hausdorff distance, 95th percentile of Hausdorff distance, and Intersection over Union. Results During the testing phase, CTV segmentation with 3D U-Net, 3D Res U-Net, and V-Net showed a mean Dice similarity coefficient of 0.90 ± 0.07, 0.95 ± 0.06, and 0.95 ± 0.06, a mean Hausdorff distance of 2.51 ± 1.70, 0.96 ± 1.01, and 0.98 ± 0.95 mm, a mean 95th percentile of Hausdorff distance of 1.33 ± 1.02, 0.65 ± 0.91, and 0.40 ± 0.72 mm, and a mean Intersection over Union of 0.85 ± 0.11, 0.91 ± 0.09, and 0.92 ± 0.09, respectively. Segmentation based on V-Net was similarly to that performed by experienced radiation oncologists. The CTV segmentation time was < 3.2 s, which could save the work time of clinicians. Conclusion V-Net is better than other models in CTV segmentation as indicated by quantitative metrics and clinician assessment. Additionally, the method is highly consistent with the ground truth, reducing inter-doctor variability and treatment time.
2.Literature analysis of output dose verification for linear accelerators in China
Hongbo WANG ; Xiangbo WAN ; Qinfu ZHANG ; Xiaojun CHENG ; Xian XUE ; Zhijian HE ; Jinsheng CHENG ; Yuexin GUO ; Quanfu SUN
Chinese Journal of Radiological Medicine and Protection 2024;44(12):1034-1042
Objective:To analyze the current situation of dosimetry audits for linear accelerators in China comprehensively based on the literature, including the range of output dose deviation and the qualified rate of output dose deviation.Methods:Literature search including non-full-text was carried out in CNKI database for literature on output dose verification using dosimeter comparison and quality control test, respectively. Data extraction and analysis were carried out for each kind of eligible literature. The data on the number of tested linear accelerators, the number of qualified linear accelerators, the qualified rate of output dose deviation and the range of output dose deviation were extracted, and the total qualified rate of output dose deviation was calculated based on the total number of tested linear accelerators and the total number of qualified linear accelerators. The data on qualified rate of output dose deviation and output dose deviation in past years were sorted out and their trend was analyzed.Results:A total of 11 literatures using dosimeter comparison method for output dose verification were retrieved, and the total qualified rate of the output dose deviation reported in these literatures was 90.7%. The qualified rate of the output dose deviation in the early years was either as low as 75% or as high as 100%, and remained around 90% in recent years. A total of 19 literatures using quality control test method for output dose verification were retrieved, and the total qualified rate of X-ray and electron beam output dose deviation reported in these literatures was 86.5% and 78.4%, respectively. Of the 12 data on X-ray output dose qualified rate in 2014-2019, 8 were below 90.0% and 4 were above 90.0%. Of the 7 data on X-ray output dose qualified rate in 2020-2023, 2 were below 90.0% and 5 were greater than or equal to 90.0%. The qualified rate of electron beam output dose was 46.2%-80.0% before 2021 and 100% from 2021 to 2023.Conclusions:The qualified rate of the output dose deviation of linear accelerators in China reported in the literature in recent years is on the rise, but the total qualified rate of the output dose deviation of linear accelerators in China is still lower than in developed countries. In order to ensure the therapeutic effect of the patients undergoing radiotherapy, measures should be taken to reduce the output dose deviation of linear accelerators and improve the level of qualified rate of output dose verification.
3.Literature analysis of output dose verification for linear accelerators in China
Hongbo WANG ; Xiangbo WAN ; Qinfu ZHANG ; Xiaojun CHENG ; Xian XUE ; Zhijian HE ; Jinsheng CHENG ; Yuexin GUO ; Quanfu SUN
Chinese Journal of Radiological Medicine and Protection 2024;44(12):1034-1042
Objective:To analyze the current situation of dosimetry audits for linear accelerators in China comprehensively based on the literature, including the range of output dose deviation and the qualified rate of output dose deviation.Methods:Literature search including non-full-text was carried out in CNKI database for literature on output dose verification using dosimeter comparison and quality control test, respectively. Data extraction and analysis were carried out for each kind of eligible literature. The data on the number of tested linear accelerators, the number of qualified linear accelerators, the qualified rate of output dose deviation and the range of output dose deviation were extracted, and the total qualified rate of output dose deviation was calculated based on the total number of tested linear accelerators and the total number of qualified linear accelerators. The data on qualified rate of output dose deviation and output dose deviation in past years were sorted out and their trend was analyzed.Results:A total of 11 literatures using dosimeter comparison method for output dose verification were retrieved, and the total qualified rate of the output dose deviation reported in these literatures was 90.7%. The qualified rate of the output dose deviation in the early years was either as low as 75% or as high as 100%, and remained around 90% in recent years. A total of 19 literatures using quality control test method for output dose verification were retrieved, and the total qualified rate of X-ray and electron beam output dose deviation reported in these literatures was 86.5% and 78.4%, respectively. Of the 12 data on X-ray output dose qualified rate in 2014-2019, 8 were below 90.0% and 4 were above 90.0%. Of the 7 data on X-ray output dose qualified rate in 2020-2023, 2 were below 90.0% and 5 were greater than or equal to 90.0%. The qualified rate of electron beam output dose was 46.2%-80.0% before 2021 and 100% from 2021 to 2023.Conclusions:The qualified rate of the output dose deviation of linear accelerators in China reported in the literature in recent years is on the rise, but the total qualified rate of the output dose deviation of linear accelerators in China is still lower than in developed countries. In order to ensure the therapeutic effect of the patients undergoing radiotherapy, measures should be taken to reduce the output dose deviation of linear accelerators and improve the level of qualified rate of output dose verification.
4.Assessment of Prospective Cancer Risks from Occupational Exposure to Ionizing Radiation—Introduction to IAEA TECDOC 1985
XUE Xian ; SU Yinping ; ZHANG Pinhua ; SUN Quanfu
Chinese Journal of Radiological Health 2022;31(5):531-534
Abstract
As part of the human environment, ionizing radiation can produce adverse tissue reactions known as determinist-
ic effects at sufficiently high exposure levels, and cause stochastic effects (cancer and genetic diseases), where single cells
with mutations can trigger somatic or genetic effects, even at low exposure levels. Given the unfavorable health effects of ra-
diation, a comprehensive technical report is warranted to address the measurement and control of radiation exposure levels.
The Assessment of Prospective Cancer Risks from Occupational Exposure to Ionizing Radiation published by the Internation-
al Atomic Energy Agency fills this gap. This paper outlines the methodology of prospective cancer risk assessment for work-
ers occupationally exposed to radiation, which provides a flexible framework based on radiobiology, risk modeling, and epi-
demiological data and a new tool for managing occupational radiation exposure and assessing potential risks from occupa-
tional radiation exposure.
5.Calcium/also a double-edged sword?
Chinese Pharmacological Bulletin 2003;0(11):-
Calcium supplement is needed for Chinese people.Calcium antagonists are also used in China.Authors suggest that calcium owns dual direction effects like a double-edged sword.Based on the knowledge of calcium metabolism,the adverse drugs reactions of excessive calcium supplement and the harmful effects of cellular calcium overload are introduced.Scientific and efficient application of calcium agents and calcium antagonists is expected.
6.Role of β-adrenoceptor at different stages of bronchial asthma
Haipeng GAO ; Youhua LIN ; Quanfu XUE ; Lirong WANG ; Guangjin ZHU ; Qiping ZHAO ; Yuzhi CHEN
Chinese Medical Journal 2001;114(12):1317-1319
Objective To investigate the changes of β-adrenergic receptor (βAR) in peripheral lymphocytes and β2AR mRNA levels at different stages of bronchial asthma. Methods β2AR density and β2AR mRNA level in peripheral lymphocytes, cAMP and cGMP levels in blood plasma were estimated by radioligand binding assay, radioimmunoassay and RT-PCR.Results (1) Maximum bound volume (Bmax) and equilibrium dissociation constant (Kd) of β2AR of lymphocyte in asthma patients at remission stage were markedly higher than that in normal subjects, while cAMP levels in blood plasma showed no difference. Bmax of β2AR and cAMP levels in asthma patients at acute exacerbation stage were significantly lower than that in normal subjects, and Kds between these two groups were not much different. (2) Expression of β2ARmRNA in peripheral lymphocytes of asthmatics at remission stage was not significantly different compared with that in normals. Conclusions Amount and function of βAR and β2ARmRNA levels are related to asthmatic conditions. Changes of βAR and β2ARmRNA in asthma might rather be a pathological change accompanied by the course of the disease than a primary defect.
7.The therapeutic effect of frequency spectrum equipment of the rat epilepsy model and the influence on the pia microcirculatory blood flow volume
Yunqing WU ; Qin SI ; Baoqiang WU ; Shunling DAI ; Quanfu XUE ; Huimin SHAN ; Zibin YANG
Chinese Journal of Rehabilitation Theory and Practice 2000;6(4):145-148
The epilepsy symptom and the pia microcirculatory blood flow volume (PMBFV) were investigated in epilepsy rat model induced by strychnine and the changes after treatment by using faradized frequency spectrum therapeutic equipment were observed. The epilepsy symptom was improved and the PMBFV increased after treatment. The convulsion seizure time was delayed, the seizure frequency and convulsion time were reduced, and the epilepsy even was not appeared in some cases. Results suggested that this improvement might be related to the change of PMBFV.
8.Response change of rat mesenteric microvessels to noradrenaline during endotoxic shock
Chinese Journal of Pathophysiology 1989;0(06):-
The response of rat mesenteric microvessels to noradrenaline (NA) in different stages of endotoxic shock was investigated by using vital microscope with video television recorder. It was found that the diameter of the microvessels showed a dose-dependent decrease to local NA application from the low to high concentration. The constricted response curve was remained unchanged at the experimental duration. The constricted response to NA was increased significantly at early stage of shock but was decreased at late stage (both P
9.Ca~(2+) signaling and pancreatitis
Chinese Pharmacological Bulletin 1987;0(03):-
To date, pancreatitis lacks of specific pharmacological therapy. Recently, it has been found that cytosolic Ca2+ overload causes pancreatitis. This article summarized the earliest events of Ca2+ transport in pancreatic acinar cell during pancreatitis and the influence of bile, alcohol, and hyperlipidaemia.Abnormal Ca2+ signal can be inhibited by caffeine. Based on these results, potential therapeutic targets are suggested.
10.The effect of isobaric hypoxia on the density of subtypes of ? and ? adrenoceptors in rat lung
Chinese Journal of Pathophysiology 1986;0(03):-
Rats were kept in isobaric hypoxic chamber (O_2=10%)for ? , ? and 4 weeks(6h/day, 6days/week). The lung adrenoceptors were measured by radioligand bindingtechnique. Results showed that the ? adrenoceptor increased at 1st week of hypoxia and de-creased significantly at 2nd and 4th weeks of hypoxia. The change of ?_2 adrenoceptor wasconsistant with that of total ? adrenoceptor but the decrease was more significant. By con-trast, the ?_2 adrenoceptor increased significantly all the time. No change of Kd valuewas found in this study. The data indicated that the changes of adrenoceptors induced byhypoxia caused the domination of pulmonary vasoconstriction which may play a role inthe developement of hypoxic pulmonary hypertension.


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