Pub Date : 2020-02-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.02.004
Xue-Lei Tian, X. Lu, Jiang-bin Feng, Yumin Lyu, Mei Tian, Qing-Jie Liu
Objective To study the effects of sex, age, length of service, type of work and annual effective radiation dose on nucleoplasmic bridge (NPB) in the peripheral blood lymphocytes of radiation workers. Methods The peripheral blood samples of 100 radiation workers in Henan province were collected and the NPB in peripheral blood lymphocytes were measured by CBMN assay. The frequencies of NPB formation and NPB-containing cells were calculated, and the effects of various factors on NPB incidence were analyzed statistically. Results The NPB frequency in radiation workers was higher than that in healthy people (Z=-8.123, P<0.01). Except for sex, the factors of age, length of service, type of work and annual effective dose had significant influences on NPB (χ2= 7.202-45.571, P<0.05). Conclusions NPB reflects the effect of low-dose long-term chronic irradiation on the occupational radiation workers. Key words: Nucleoplasmic bridges; Radiation worker; Influence factors; Ionizing radiation
{"title":"Influence factors of nucleoplasmic bridge frequencies in the peripheral blood lymphocytes of radiation workers","authors":"Xue-Lei Tian, X. Lu, Jiang-bin Feng, Yumin Lyu, Mei Tian, Qing-Jie Liu","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.02.004","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.02.004","url":null,"abstract":"Objective \u0000To study the effects of sex, age, length of service, type of work and annual effective radiation dose on nucleoplasmic bridge (NPB) in the peripheral blood lymphocytes of radiation workers. \u0000 \u0000 \u0000Methods \u0000The peripheral blood samples of 100 radiation workers in Henan province were collected and the NPB in peripheral blood lymphocytes were measured by CBMN assay. The frequencies of NPB formation and NPB-containing cells were calculated, and the effects of various factors on NPB incidence were analyzed statistically. \u0000 \u0000 \u0000Results \u0000The NPB frequency in radiation workers was higher than that in healthy people (Z=-8.123, P<0.01). Except for sex, the factors of age, length of service, type of work and annual effective dose had significant influences on NPB (χ2= 7.202-45.571, P<0.05). \u0000 \u0000 \u0000Conclusions \u0000NPB reflects the effect of low-dose long-term chronic irradiation on the occupational radiation workers. \u0000 \u0000 \u0000Key words: \u0000Nucleoplasmic bridges; Radiation worker; Influence factors; Ionizing radiation","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"20 1","pages":"94-98"},"PeriodicalIF":0.0,"publicationDate":"2020-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89919061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.02.002
Dan Yao, Junling Zhang, Wang Zheng, Qianping Chen, Songling Hu, Yan Pan
Objective To investigate the effect of fractionated radiotherapy on the immune system of mice with subcutaneously transplanted hepatocellular carcinoma. Methods Logarithmic growth of mouse hepatocellular carcinoma cells Hepa 1-6 were inoculated subcutaneously on the right side of C57BL/6 J mice (1×107 cells /mice). The tumor-bearing mice were randomly divided into control group (Ctrl) and irradiation group (IR), 20 mice in each group. Additionally, 10 healthy mice were set as normal control group. Local fractionated X-ray irradiation of 8 Gy×3 fraction was given to the subcutaneous tumors, and the dose rate was 0.883 Gy/min. At 7 and 14 d after irradiation, the tumor organ index, spleen organ index, spleen pathological changes, and splenic T lymphocyte subsets, B lymphocyte subsets, and NK cells were detected. Results Compared with Ctrl, at 7 and 14 d after irradiation, the tumor organ index decreased (t=4.649, 26.34, P<0.05), and the percentage of NK cells increased significantly (t=3.952, 3.633, P<0.05). The percentages of CD3+ , CD4+ , CD3+ CD4+ lymphocytes and the ratio of CD4+ /CD8+ lymphocyte decreased at 7 d after irradiation (t=3.193, 3.656, 3.219, 2.641, P<0.05), and the percentage of CD3+ lymphocyte decreased at 14 d after irradiation (t=3.031, P<0.05). But after irradiation, there were no significant changes in spleen organ index, B lymphocyte, CD3+ CD4+ lymphocyte and CD8+ lymphocyte. Conclusions Local hepatoma radiotherapy causes imbalance of lymphocytes in distal spleen of mice and hence reduces immunity, which provides a novel mechanism of radiological immunity damage. Key words: Hepatocellular carcinoma; Fractionated radiotherapy; Splenic lymphocytes
{"title":"Effect of fractionated radiotherapy of transplanted hepatocellular carcinoma on the splenic immune cells in mice","authors":"Dan Yao, Junling Zhang, Wang Zheng, Qianping Chen, Songling Hu, Yan Pan","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.02.002","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.02.002","url":null,"abstract":"Objective \u0000To investigate the effect of fractionated radiotherapy on the immune system of mice with subcutaneously transplanted hepatocellular carcinoma. \u0000 \u0000 \u0000Methods \u0000Logarithmic growth of mouse hepatocellular carcinoma cells Hepa 1-6 were inoculated subcutaneously on the right side of C57BL/6 J mice (1×107 cells /mice). The tumor-bearing mice were randomly divided into control group (Ctrl) and irradiation group (IR), 20 mice in each group. Additionally, 10 healthy mice were set as normal control group. Local fractionated X-ray irradiation of 8 Gy×3 fraction was given to the subcutaneous tumors, and the dose rate was 0.883 Gy/min. At 7 and 14 d after irradiation, the tumor organ index, spleen organ index, spleen pathological changes, and splenic T lymphocyte subsets, B lymphocyte subsets, and NK cells were detected. \u0000 \u0000 \u0000Results \u0000Compared with Ctrl, at 7 and 14 d after irradiation, the tumor organ index decreased (t=4.649, 26.34, P<0.05), and the percentage of NK cells increased significantly (t=3.952, 3.633, P<0.05). The percentages of CD3+ , CD4+ , CD3+ CD4+ lymphocytes and the ratio of CD4+ /CD8+ lymphocyte decreased at 7 d after irradiation (t=3.193, 3.656, 3.219, 2.641, P<0.05), and the percentage of CD3+ lymphocyte decreased at 14 d after irradiation (t=3.031, P<0.05). But after irradiation, there were no significant changes in spleen organ index, B lymphocyte, CD3+ CD4+ lymphocyte and CD8+ lymphocyte. \u0000 \u0000 \u0000Conclusions \u0000Local hepatoma radiotherapy causes imbalance of lymphocytes in distal spleen of mice and hence reduces immunity, which provides a novel mechanism of radiological immunity damage. \u0000 \u0000 \u0000Key words: \u0000Hepatocellular carcinoma; Fractionated radiotherapy; Splenic lymphocytes","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"75 1","pages":"82-87"},"PeriodicalIF":0.0,"publicationDate":"2020-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83821784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.02.005
Xinyuan Chen, Jiming Yang, J. Yi, J. Dai
Objective To train individualized three-dimensional (3D) dose prediction models for radiotherapy planning, and use the models to establish a planning quality control method . Methods A total of 99 cases diagnosed as early nasopharyngeal carcinoma (NPC) were analyzed retrospectively, who received simultaneous integrated boost (SIB) with volumetric modulated arc therapy (VMAT). Seven geometric features were extracted, including the minimum distance features from each organs at risk (OARs) to planning target volume (PTV), boost targets and outline, as well as four coordinate position characteristics.89 cases were trained and 10 cases were tested based on 3D dose distribution prediction models using artificial neural network (ANN). A planning quality control method were established based on the prediction models. The dosimetric parameters including D2%, D25%, D50%, D75% and mean dose (MD) of each OAR were used as quality control indicators, and the passing criteria was defined as that the dosimetric difference between manual planning and the predicted dose should be less than 10%. The quality control method was tested with 10 plans designed by a junior physicist. Results There was no significant discrepancy between the model predicted dose and the result of expert plan in the main dosimetric indexes of 18 OARs. The dose differences of D2%, D25%, D50%, D75% and MD were all controlled within 1.2 Gy.All the 10 plans designed by a junior physicist reached the general clinical dose requirements, while by using our proposes quality control method, one of these plans was observed not optimal enough and some dosimetric parameters of spinal cord, spinal cord PRV, brainstem and brainstem PRV could be improved. After re-optimizing this plan according to the predicted values of the model, the D2% of spinal cord and brainstem decreased by 8.4 Gy and 5.8 Gy, respectively. Conclusions This study proposes a simple and convenient quality control method for radiotherapy planning. This method could overcome the disadvantage of unified dose constrains without considering patient-specific conditions, and improve the quality and stability of individualized radiotherapy planning. Key words: Radiotherapy planning; Dose prediction; Artificial neural network; Quality control; Nasopharyngeal carcinoma
{"title":"Quality control of VMAT planning using artificial neural network models for nasopharyngeal carcinoma","authors":"Xinyuan Chen, Jiming Yang, J. Yi, J. Dai","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.02.005","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.02.005","url":null,"abstract":"Objective \u0000To train individualized three-dimensional (3D) dose prediction models for radiotherapy planning, and use the models to establish a planning quality control method . \u0000 \u0000 \u0000Methods \u0000A total of 99 cases diagnosed as early nasopharyngeal carcinoma (NPC) were analyzed retrospectively, who received simultaneous integrated boost (SIB) with volumetric modulated arc therapy (VMAT). Seven geometric features were extracted, including the minimum distance features from each organs at risk (OARs) to planning target volume (PTV), boost targets and outline, as well as four coordinate position characteristics.89 cases were trained and 10 cases were tested based on 3D dose distribution prediction models using artificial neural network (ANN). A planning quality control method were established based on the prediction models. The dosimetric parameters including D2%, D25%, D50%, D75% and mean dose (MD) of each OAR were used as quality control indicators, and the passing criteria was defined as that the dosimetric difference between manual planning and the predicted dose should be less than 10%. The quality control method was tested with 10 plans designed by a junior physicist. \u0000 \u0000 \u0000Results \u0000There was no significant discrepancy between the model predicted dose and the result of expert plan in the main dosimetric indexes of 18 OARs. The dose differences of D2%, D25%, D50%, D75% and MD were all controlled within 1.2 Gy.All the 10 plans designed by a junior physicist reached the general clinical dose requirements, while by using our proposes quality control method, one of these plans was observed not optimal enough and some dosimetric parameters of spinal cord, spinal cord PRV, brainstem and brainstem PRV could be improved. After re-optimizing this plan according to the predicted values of the model, the D2% of spinal cord and brainstem decreased by 8.4 Gy and 5.8 Gy, respectively. \u0000 \u0000 \u0000Conclusions \u0000This study proposes a simple and convenient quality control method for radiotherapy planning. This method could overcome the disadvantage of unified dose constrains without considering patient-specific conditions, and improve the quality and stability of individualized radiotherapy planning. \u0000 \u0000 \u0000Key words: \u0000Radiotherapy planning; Dose prediction; Artificial neural network; Quality control; Nasopharyngeal carcinoma","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"44 1","pages":"99-105"},"PeriodicalIF":0.0,"publicationDate":"2020-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86897707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.02.007
Shan Li, Xuezhen Wang, Yanbin Chen, Zan-yi Wu, Hairong Zhang, J. Zeng, C. Cai, Weijian Zhang, Li Su, Jinsheng Hong
Objective To retrospectively analyze the efficacy and prognostic factors of postoperative intensity modulated radiotherapy for grade Ⅱ gliomas. Methods Retrospective analysis was conducted on patients with postoperative grade Ⅱ glioma in our hospital from Jan. 2010 to Dec. 2018. The primary endpoint was progression-free survival, and the secondary endpoint was overall survival. Correlative analyses of prognosis by age, gender, initial resection status, the maximum diameter of the lesions, bi-hemisphere, astrocytoma, chemoradiation, adjuvant chemotherapy were conducted. Results A total of 109 cases with grade Ⅱ glioma were enrolled. The follow-up rate was 91.75%, including 10 cases dead and 27 relapsed. There were 24 cases (88.9%) of in-field failure, and 3 cases (11.1%) of out-field failure. 14 cases of recurrence occurred in 81 cases of total resection group, accounting for 17.3%, and 13 in 28 cases of subtotal resection group, accounting for 46.4%. The recurrence rate in the subtotal resection group was significantly higher than that in the total resection group (χ2=9.484, P<0.05). The 1-, 2-, 3-, 4- and 5-year progression-free survival rates were 92.5%, 86.0%, 80.6%, 77.5% and 66.8%, respectively. The 2-, 3-, 4- and 5-year overall survival rates were 97.2%, 90.8%, 87.7% and 84.5%, respectively. Multivariate analysis showed that patients with subtotal resection(HR=3.608, P<0.05) and bi-hemisphere(HR=3.183, P<0.05)were significantly correlated with the progression free survival. Conclusions Postoperative intensity modulated radiotherapy for grade Ⅱ gliomas can achieve a better PFS. Recurrence in the radiation field is the main failure mode. Initial resection status and bi-hemisphere of tumor are important influential factors for PFS of grade Ⅱ gliomas patients. Key words: Grade Ⅱ glioma; Intensity modulated radiotherapy; Efficacy; Prognosis
{"title":"The efficacy of gradeII glioma with postoperative intensity modulated radiotherapy","authors":"Shan Li, Xuezhen Wang, Yanbin Chen, Zan-yi Wu, Hairong Zhang, J. Zeng, C. Cai, Weijian Zhang, Li Su, Jinsheng Hong","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.02.007","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.02.007","url":null,"abstract":"Objective \u0000To retrospectively analyze the efficacy and prognostic factors of postoperative intensity modulated radiotherapy for grade Ⅱ gliomas. \u0000 \u0000 \u0000Methods \u0000Retrospective analysis was conducted on patients with postoperative grade Ⅱ glioma in our hospital from Jan. 2010 to Dec. 2018. The primary endpoint was progression-free survival, and the secondary endpoint was overall survival. Correlative analyses of prognosis by age, gender, initial resection status, the maximum diameter of the lesions, bi-hemisphere, astrocytoma, chemoradiation, adjuvant chemotherapy were conducted. \u0000 \u0000 \u0000Results \u0000A total of 109 cases with grade Ⅱ glioma were enrolled. The follow-up rate was 91.75%, including 10 cases dead and 27 relapsed. There were 24 cases (88.9%) of in-field failure, and 3 cases (11.1%) of out-field failure. 14 cases of recurrence occurred in 81 cases of total resection group, accounting for 17.3%, and 13 in 28 cases of subtotal resection group, accounting for 46.4%. The recurrence rate in the subtotal resection group was significantly higher than that in the total resection group (χ2=9.484, P<0.05). The 1-, 2-, 3-, 4- and 5-year progression-free survival rates were 92.5%, 86.0%, 80.6%, 77.5% and 66.8%, respectively. The 2-, 3-, 4- and 5-year overall survival rates were 97.2%, 90.8%, 87.7% and 84.5%, respectively. Multivariate analysis showed that patients with subtotal resection(HR=3.608, P<0.05) and bi-hemisphere(HR=3.183, P<0.05)were significantly correlated with the progression free survival. \u0000 \u0000 \u0000Conclusions \u0000Postoperative intensity modulated radiotherapy for grade Ⅱ gliomas can achieve a better PFS. Recurrence in the radiation field is the main failure mode. Initial resection status and bi-hemisphere of tumor are important influential factors for PFS of grade Ⅱ gliomas patients. \u0000 \u0000 \u0000Key words: \u0000Grade Ⅱ glioma; Intensity modulated radiotherapy; Efficacy; Prognosis","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"19 1","pages":"112-115"},"PeriodicalIF":0.0,"publicationDate":"2020-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80245000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-13DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.02.001
Q. Sun
{"title":"Salute to the radiation workers with duty to defend our land against the outbreak of novel coronavirus pneumonia","authors":"Q. Sun","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.02.001","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.02.001","url":null,"abstract":"","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"14 1","pages":"81-81"},"PeriodicalIF":0.0,"publicationDate":"2020-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80103369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.01.004
Jianxin Ren, G. Gong, Xingmin Ma, X. Yao, Yong Yin
Objective To study the effects of different CT values assignment methods on the dose calculation of radiotherapy plan for brain metastases, which will provide a reference for radiotherapy treatment planning based on MR images. Methods A total of 35 patients treated with radiotherapy for brain metastases were selected, with pre-treatment CT and MR simulated positioning performed at the same day. Based on the simulation CT images, three dimensional conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT) plans were calculated as the original plan (Plan1). The CT and MR images were rigidly registered and then the main tissues and organs were delineated on CT and MR images. The average CT values of each tissue and organ were calculated. Three groups of pseudo CT were generated by three CT values assignment methods based on the CT images: whole tissue was assigned 140 HU; cavity, bone and other tissues were assigned -700 HU, 700 HU and 20 HU, respectively; different tissues and organs were assigned corresponding CT values. The dose distribution of Plan1 was recalculated on three groups of pseudo-CT to obtain Plan2, Plan3 and Plan4, respectively. Finally, the dosimetric difference between Plan1 and other plans (including Plan2, Plan3 and Plan4) were compared. Results The average CT values of bone and cavity were (735.3±68.0) HU and (-723.9±27.0) HU, respectively. The average CT values of soft tissues was mostly distributed from -70 to 70 HU. The dosimetric differences between Plan2, Plan3, Plan4, and Plan1 decreased in turn. The differences of maximum dose of lens were the biggest, which can reach more than 5.0%, 1.5%-2.0% and 1.0%-1.5%, respectively, and the differences of other dose parameters were basically less than 2.0%, 1.2% and 0.8%, respectively. In the pixelwise dosimetric comparison, the areas with more than 1% difference in the local target cases were mainly distributed in the skin near the field. On the other hand, those in the whole brain target cases were mainly distributed at the bone, cavity, bone and soft tissues junction, and the skin near the field. In addition, the dose calculation error of CT value assignment methods in 3D-CRT plan was slightly larger than that in IMRT plan, and that in whole brain target cases were significantly larger than that in local target cases. Conclusions Different CT value assignment methods have a significant effect on the dose calculation of radiotherapy for brain metastases. When appropriate CT values are given to bone, air cavity and soft tissue, respectively, the deviation of dose calculation can be basically controlled within 1.2%. And by assigning mass CT values to various tissues and organs, the deviation can be further controlled within 0.8%, which can meet the clinical requirements. Key words: Brain metastases; CT values; Pseudo CT; Dose comparison
{"title":"Study on the effects of different CT values assignment methods on dose calculation of brain metastases radiotherapy","authors":"Jianxin Ren, G. Gong, Xingmin Ma, X. Yao, Yong Yin","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.01.004","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.01.004","url":null,"abstract":"Objective \u0000To study the effects of different CT values assignment methods on the dose calculation of radiotherapy plan for brain metastases, which will provide a reference for radiotherapy treatment planning based on MR images. \u0000 \u0000 \u0000Methods \u0000A total of 35 patients treated with radiotherapy for brain metastases were selected, with pre-treatment CT and MR simulated positioning performed at the same day. Based on the simulation CT images, three dimensional conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT) plans were calculated as the original plan (Plan1). The CT and MR images were rigidly registered and then the main tissues and organs were delineated on CT and MR images. The average CT values of each tissue and organ were calculated. Three groups of pseudo CT were generated by three CT values assignment methods based on the CT images: whole tissue was assigned 140 HU; cavity, bone and other tissues were assigned -700 HU, 700 HU and 20 HU, respectively; different tissues and organs were assigned corresponding CT values. The dose distribution of Plan1 was recalculated on three groups of pseudo-CT to obtain Plan2, Plan3 and Plan4, respectively. Finally, the dosimetric difference between Plan1 and other plans (including Plan2, Plan3 and Plan4) were compared. \u0000 \u0000 \u0000Results \u0000The average CT values of bone and cavity were (735.3±68.0) HU and (-723.9±27.0) HU, respectively. The average CT values of soft tissues was mostly distributed from -70 to 70 HU. The dosimetric differences between Plan2, Plan3, Plan4, and Plan1 decreased in turn. The differences of maximum dose of lens were the biggest, which can reach more than 5.0%, 1.5%-2.0% and 1.0%-1.5%, respectively, and the differences of other dose parameters were basically less than 2.0%, 1.2% and 0.8%, respectively. In the pixelwise dosimetric comparison, the areas with more than 1% difference in the local target cases were mainly distributed in the skin near the field. On the other hand, those in the whole brain target cases were mainly distributed at the bone, cavity, bone and soft tissues junction, and the skin near the field. In addition, the dose calculation error of CT value assignment methods in 3D-CRT plan was slightly larger than that in IMRT plan, and that in whole brain target cases were significantly larger than that in local target cases. \u0000 \u0000 \u0000Conclusions \u0000Different CT value assignment methods have a significant effect on the dose calculation of radiotherapy for brain metastases. When appropriate CT values are given to bone, air cavity and soft tissue, respectively, the deviation of dose calculation can be basically controlled within 1.2%. And by assigning mass CT values to various tissues and organs, the deviation can be further controlled within 0.8%, which can meet the clinical requirements. \u0000 \u0000 \u0000Key words: \u0000Brain metastases; CT values; Pseudo CT; Dose comparison","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"117 1","pages":"26-31"},"PeriodicalIF":0.0,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75756232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.01.003
Tao Yang, Xu Shouping, C. Xie, Gong Xuan, W. Xu, B. Qu, Zishen Wang, Chunfeng Fang, L. Cao
Objective To study the dosimetric characteristics and plan quality of PTV-based intensity modulated proton radiotherapy (IMPT) and volumetric-modulated arc therapy (VMAT) plans for prostate cancer, so as to provide a reference for clinical application. Methods A total of 10 prostate cancer cases were included in this retrospective study. IMPT and RapidArc plans were designed by RayStation and Eclipse TPS based on PTV, respectively. For each case, IMPT plans were generated using multiple field optimization (MFO) technique with two parallel-opposed lateral fields, whereas RapidArc plans were generated using double-arc technique (two full arcs). Final dose calculation of IMPT was conducted by pencil beam(PB) and Monte Carlo (MC) algorithm, respectively, with adopted data model from the pencil beam scanning (PBS) proton therapy system of IBA Protues Plus(IBA Group, Belgium); The data model originated from the linear accelerator of Varian Clinac iX (Varian Medical Systems, America) was used for RapidArc plans. Dosimetric parameters of DVH and dose distribution were used to compare the dose differences in targets and organs at risk (OARs) between these two treatment techniques. Results For targets, HIs of PB-IMPT and MC-IMPT were slightly better than that of RapidArc , but CI of IMPT was slightly lower than that of RapidArc; D1% of PB-IMPT was significantly better than those of MC-IMPT and RapidArc (Z=-2.805, -2.803, P<0.05). PB-IMPT and MC-IMPT achieved better protection than RapidArc on rectum V30(Z=-2.191, -1.988, P<0.05)and Dmean(Z=-2.599, -2.497, P<0.05), bladder V30(Z=-2.701, -2.701, P<0.05), V40(Z=-2.395, -2.395, P<0.05)and Dmean(Z=-2.701, -2.701, P<0.05). There was no significant difference between PB-IMPT and MC-IMPT plans for prostate cancer, except for the D1% [(73.86±67.34) Gy vs.(75.45±2.01) Gy] (RBE) and HI [(0.040±0.010) vs. (0.058±0.020)] of the target. Conclusions Both techniques can meet the clinical requirements, but IMPT showed significant dosimetric advantages compared with RapidArch by reducing the dose to OARs and improving the plan quality. Key words: Prostate cancer; IMPT; VMAT; RapidArc; PBS
{"title":"Evaluation of plan quality for IMPT and VMAT in the treatment of patients with prostate cancer","authors":"Tao Yang, Xu Shouping, C. Xie, Gong Xuan, W. Xu, B. Qu, Zishen Wang, Chunfeng Fang, L. Cao","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.01.003","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.01.003","url":null,"abstract":"Objective To study the dosimetric characteristics and plan quality of PTV-based intensity modulated proton radiotherapy (IMPT) and volumetric-modulated arc therapy (VMAT) plans for prostate cancer, so as to provide a reference for clinical application. Methods A total of 10 prostate cancer cases were included in this retrospective study. IMPT and RapidArc plans were designed by RayStation and Eclipse TPS based on PTV, respectively. For each case, IMPT plans were generated using multiple field optimization (MFO) technique with two parallel-opposed lateral fields, whereas RapidArc plans were generated using double-arc technique (two full arcs). Final dose calculation of IMPT was conducted by pencil beam(PB) and Monte Carlo (MC) algorithm, respectively, with adopted data model from the pencil beam scanning (PBS) proton therapy system of IBA Protues Plus(IBA Group, Belgium); The data model originated from the linear accelerator of Varian Clinac iX (Varian Medical Systems, America) was used for RapidArc plans. Dosimetric parameters of DVH and dose distribution were used to compare the dose differences in targets and organs at risk (OARs) between these two treatment techniques. Results For targets, HIs of PB-IMPT and MC-IMPT were slightly better than that of RapidArc , but CI of IMPT was slightly lower than that of RapidArc; D1% of PB-IMPT was significantly better than those of MC-IMPT and RapidArc (Z=-2.805, -2.803, P<0.05). PB-IMPT and MC-IMPT achieved better protection than RapidArc on rectum V30(Z=-2.191, -1.988, P<0.05)and Dmean(Z=-2.599, -2.497, P<0.05), bladder V30(Z=-2.701, -2.701, P<0.05), V40(Z=-2.395, -2.395, P<0.05)and Dmean(Z=-2.701, -2.701, P<0.05). There was no significant difference between PB-IMPT and MC-IMPT plans for prostate cancer, except for the D1% [(73.86±67.34) Gy vs.(75.45±2.01) Gy] (RBE) and HI [(0.040±0.010) vs. (0.058±0.020)] of the target. Conclusions Both techniques can meet the clinical requirements, but IMPT showed significant dosimetric advantages compared with RapidArch by reducing the dose to OARs and improving the plan quality. Key words: Prostate cancer; IMPT; VMAT; RapidArc; PBS","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"7 1","pages":"19-25"},"PeriodicalIF":0.0,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84748913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.01.006
Jiahao Wang, Peng-jun Zhao, Lixia Xu, Jianjun Lai, Q. Deng
Objective To compare the irradiated dose to unprotected lymph node stations (LNS) between volume-modulated arc therapy (VMAT) and 5-field intensity-modulated radiotherapy (5F-IMRT) in the treatment of patients with upper thoracic esophageal cancer. Methods A total of 20 patients were selected for re-planning. LNS were not included in the GTV and CTV, instead, LNS were contoured as normal tissues. However, LNS were not constrained in the VMAT and 5F-IMRT inverse optimization for protection. Dosimetric parameters of conformal index (CI), homogeneity index (HI) of targets, V95, V110 of planning target volume (PTV), Dmean, V5, V20, V30 of lung, Dmean, V25 of heart, Dmax of spinal cord, MU, as well as the equivalent uniform dose (EUD) and V40 of LNS were compared between the two plans. Results 5F-IMRT was superior in PTV_V95% (t=-9.4, P<0.05), but worse in terms of CI (t=-5.3, P<0.05) compared with VMAT. 5F-IMRT reduced the V5 of lung by 10.9% (t=-7.8, P<0.05) and the Dmax of spinal cord by 9% (t=-10.2, P<0.05), but increased the MU (t=-6.2, P<0.05) compared with VMAT. The average EUD and V40 of LNS in upper thoracic were significantly increased by 4.7% and 2.4% in 5F-IMRT compared with VMAT, respectively. The irradiated doses to LNS were significantly associated with the volume of PTV (R=0.716-0.933, P<0.05) expect for 106tbL. Conclusions The irradiated doses to unprotected LNS were less for IMRT plans and were highly associated with PTV volume in patients with upper thoracic esophageal cancer. Key words: Esophageal cancer; Irradiated dose to unprotected LNS; VMAT; IMRT
{"title":"Irradiated dose to unprotected lymph node stations in the VMAT and IMRT treatment of patients with upper thoracic esophageal cancer","authors":"Jiahao Wang, Peng-jun Zhao, Lixia Xu, Jianjun Lai, Q. Deng","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.01.006","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.01.006","url":null,"abstract":"Objective \u0000To compare the irradiated dose to unprotected lymph node stations (LNS) between volume-modulated arc therapy (VMAT) and 5-field intensity-modulated radiotherapy (5F-IMRT) in the treatment of patients with upper thoracic esophageal cancer. \u0000 \u0000 \u0000Methods \u0000A total of 20 patients were selected for re-planning. LNS were not included in the GTV and CTV, instead, LNS were contoured as normal tissues. However, LNS were not constrained in the VMAT and 5F-IMRT inverse optimization for protection. Dosimetric parameters of conformal index (CI), homogeneity index (HI) of targets, V95, V110 of planning target volume (PTV), Dmean, V5, V20, V30 of lung, Dmean, V25 of heart, Dmax of spinal cord, MU, as well as the equivalent uniform dose (EUD) and V40 of LNS were compared between the two plans. \u0000 \u0000 \u0000Results \u00005F-IMRT was superior in PTV_V95% (t=-9.4, P<0.05), but worse in terms of CI (t=-5.3, P<0.05) compared with VMAT. 5F-IMRT reduced the V5 of lung by 10.9% (t=-7.8, P<0.05) and the Dmax of spinal cord by 9% (t=-10.2, P<0.05), but increased the MU (t=-6.2, P<0.05) compared with VMAT. The average EUD and V40 of LNS in upper thoracic were significantly increased by 4.7% and 2.4% in 5F-IMRT compared with VMAT, respectively. The irradiated doses to LNS were significantly associated with the volume of PTV (R=0.716-0.933, P<0.05) expect for 106tbL. \u0000 \u0000 \u0000Conclusions \u0000The irradiated doses to unprotected LNS were less for IMRT plans and were highly associated with PTV volume in patients with upper thoracic esophageal cancer. \u0000 \u0000 \u0000Key words: \u0000Esophageal cancer; Irradiated dose to unprotected LNS; VMAT; IMRT","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"12 1","pages":"36-41"},"PeriodicalIF":0.0,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80760434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.01.013
Rungen Li, Beibei Su, N. Ma, Ying Liu, H. Bai
The diagnostic reference level (DRL) for adults radiation dose in CT examination based on a large-scale national survey data is released in the form of national health industry standards (WS/T 637-2018) after more than ten years of exploration by radiologists, imaging technologists, radiation protection specialists and radiographers. Its principles and method are in line with international practices and the actual situation in China, which basically cover frequently-used CT examination items for adults. Compared with DRL in several other countries or organizations, radiation exposure to the patients as a whole is at a reasonably low level. The 50th percentile (achievable dosimetry levels) and 25th percentile (indicative level of unusually low dosimetry) are given as additional tools for radiation dose optimization guidance. In daily activities of radiological diagnosis, the radiation dose should be matched with image quality and clinical diagnostic tasks, and the frequency of unjustifiable high or low radiation dose should be reduced. Key words: Radiation dose; Tomography, X-ray computed; Diagnostic reference levels; Radiation dose optimization
{"title":"Evolution and interpretation of diagnostic reference levels for adults undergoing X-ray computed tomography in China","authors":"Rungen Li, Beibei Su, N. Ma, Ying Liu, H. Bai","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.01.013","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.01.013","url":null,"abstract":"The diagnostic reference level (DRL) for adults radiation dose in CT examination based on a large-scale national survey data is released in the form of national health industry standards (WS/T 637-2018) after more than ten years of exploration by radiologists, imaging technologists, radiation protection specialists and radiographers. Its principles and method are in line with international practices and the actual situation in China, which basically cover frequently-used CT examination items for adults. Compared with DRL in several other countries or organizations, radiation exposure to the patients as a whole is at a reasonably low level. The 50th percentile (achievable dosimetry levels) and 25th percentile (indicative level of unusually low dosimetry) are given as additional tools for radiation dose optimization guidance. In daily activities of radiological diagnosis, the radiation dose should be matched with image quality and clinical diagnostic tasks, and the frequency of unjustifiable high or low radiation dose should be reduced. \u0000 \u0000 \u0000Key words: \u0000Radiation dose; Tomography, X-ray computed; Diagnostic reference levels; Radiation dose optimization","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"41 1","pages":"71-76"},"PeriodicalIF":0.0,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77337543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.3760/CMA.J.ISSN.0254-5098.2020.01.009
Aiguo Shen, J. Deng, Junqing Yin, Zhenjun Dong, Xingli Duan, Li-Qiong Shen, Dongying Feng, Q. Sun
Objective To standardize the occupational health management of radiation workers and raise the management level and technical content for the supervision of occupational health of radiation workers. Methods The information system for radiation worker passbook was established and applied in Hebei province for practice. Results Until December 2018, 4 339 passbooks have been issued to radiation workers from 140 medical institutions. Through the establishment and operation of the radiation worker passbook information system, the basic information and distribution characteristics of the provincial registered medical institutions and their radiation workers in Hebei province were obtained. The efficiency of the examination and approval and issuance of radiation worker certificates by the health administrative departments was improved by reducing the intermediate procedure. Conclusions Data are obtained and provided for the discussion of electronic card management of occupational health of radiation workers, real-time query of information such as medical institutions of radiation workers, education and training, individual dose monitoring, occupational health examinations, and diagnosis and identification of occupational radiological diseases. Reference basis is provided for health administrative departments to carry out radiation worker supervision. Key words: Radiation workers; Passbook; Information system; Operation
{"title":"Establishment and operation of the information system for radiation worker passbook","authors":"Aiguo Shen, J. Deng, Junqing Yin, Zhenjun Dong, Xingli Duan, Li-Qiong Shen, Dongying Feng, Q. Sun","doi":"10.3760/CMA.J.ISSN.0254-5098.2020.01.009","DOIUrl":"https://doi.org/10.3760/CMA.J.ISSN.0254-5098.2020.01.009","url":null,"abstract":"Objective \u0000To standardize the occupational health management of radiation workers and raise the management level and technical content for the supervision of occupational health of radiation workers. \u0000 \u0000 \u0000Methods \u0000The information system for radiation worker passbook was established and applied in Hebei province for practice. \u0000 \u0000 \u0000Results \u0000Until December 2018, 4 339 passbooks have been issued to radiation workers from 140 medical institutions. Through the establishment and operation of the radiation worker passbook information system, the basic information and distribution characteristics of the provincial registered medical institutions and their radiation workers in Hebei province were obtained. The efficiency of the examination and approval and issuance of radiation worker certificates by the health administrative departments was improved by reducing the intermediate procedure. \u0000 \u0000 \u0000Conclusions \u0000Data are obtained and provided for the discussion of electronic card management of occupational health of radiation workers, real-time query of information such as medical institutions of radiation workers, education and training, individual dose monitoring, occupational health examinations, and diagnosis and identification of occupational radiological diseases. Reference basis is provided for health administrative departments to carry out radiation worker supervision. \u0000 \u0000 \u0000Key words: \u0000Radiation workers; Passbook; Information system; Operation","PeriodicalId":36403,"journal":{"name":"中华放射医学与防护杂志","volume":"51 1","pages":"51-54"},"PeriodicalIF":0.0,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76602084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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