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Objective: To investigate the implementation of GBZ/T 201.3-2014 Radiation Shielding Specification for Radiotherapy Room--Part 3: Radiotherapy Room of γ-ray Sources (hereinafter referred to GBZ/T 201.3-2014). Methods: A total of 129 personnels, who were involved in the approval and supervision of radiation diagnosis and treatment construction projects in 19 provincial administrative agencies, engaged in radiation protection testing and evaluation of γ-ray radiotherapy rooms in radiation health technology service institutions, and used GBZ/T 201.3-2014 in other institutions (environmental impact assessment, education and scientific research), were selected as the participants using a stratified random sampling method. A questionnaire survey was conducted to assess their awareness and application of the standard. Results: The participants' awareness of GBZ/T 201.3-2014 was ≥63.6%, but the training rate was only 9.1% to 50.0%. The familiarity with the various chapters of the standard was over 86.4%. And 42.6% of the participants reported using the standard at least once a year. Regarding the applicability of the standard, all of the participants believed that the standard meets the needs of approval, supervision, testing, or evaluation, and adapts to the updated development of radiotherapy equipment and technology. And 94.6% of the participants believed that the use of the standard could improve the level of protection design and management, and 92.2% believed that the standard was widely applied. Regarding the adequacy of the standard, 97.7% of the participants believed that the standard's reference for ambient dose equivalent rate was reasonable, while 34.1% believed that the standard needs revision. Conclusion: The participants are satisfied with the standard and believe its applicability. They have a good level of awareness of the standard, but there is a room for improvement in their familiarity with the shielding calculation related content of the standard. The promotion, training, and practicality of the standard need to be strengthened.
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Objective @#To evaluate the implementation, application, and problems and suggestions of the Radiation Shield- ing Requirements in Room of Radiotherapy Installations—Part 1: General Principle (GBZ/T 201.1—2007) through a survey of relevant personnel in radiation health technical service institutions, and to provide a scientific basis for further revision and implementation of this standard.@*Methods@#A questionnaire survey was conducted among randomly selected per- sonnel in radiation health technical services across China, which mainly investigated the awareness, training, application, and revision suggestions related to the GBZ/T 201.1—2007. The results were aggregated and analyzed.@*Results@#A total of 184 evaluation questionnaires on the GBZ/T 201.1—2007 were collected from technical service staff in 25 provinces. Among the responders, 64.1% thought that the standard had been widely applied; 91.8% thought that the standard could meet work needs; only 54.3% ever received relevant training on the standard; 68.5% used the standard once or more per year; 33.7% thought that the standard needed to be revised.@*Conclusion@#The personnel in radiation health technical services have a high awareness rate of the GBZ/T 201.1—2007 and its contents, but their familiarity with and application of the standard need to be improved. Relevant departments should strengthen the training and promotion of the standard, and part of the standard should be revised.
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In recent years, labor dispatch has become a new form of employment in medical institutions for final disinfection, cleaning, garbage recycling and other work. Concerning the ambiguity of responsibilities and obligations in regard to dispatching workers′ occupational health management, most of employers and labor dispatching agencies failed to protect the legal rights and interests of dispatching workers during working. This article discusses the case of occupational health management and supervision of labor dispatch for cleaning worker at a nuclear medicine workplace in a medical institution.
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Objective To measure the positioning accuracy of multi-leaf collimators (MLC) leaves by using radiochromic films,with aim to providing data in support of IAEA's methodology validation.Methods The present study focused on 8 accelerators (Varian,Elekta and Siemens machines) at 6 hospitals in Henan province with highly skilled physicists.The 25 cm × 25 cm radiochromic films were put on 30 cm × 30 cm homogeneous solid phantoms and covered with a 2.0-cm-thick homogeneous solid phantom slabs.The CT-scanned images were transmitted to TPS for plan formulation.With 6 MV X-ray,MLC created 5 strip 3 cm × 0.6 cm picket fence field,each with 3.0 cm strip separation.The SSD was 100 cm at the maximum dose point,with a 250 MU to each strip.The irradiated radiochromic films were returned to IAEA for analysis within one week and compared with the values given by IAEA.Results The difference of film-measured and TPS-planned positions of MLC leaves for each strip picket fence should be within ± 0.5 mm as required by IAEA.For 7 of 8 accelerators selected,the differences of accurately measured MLC leaf positions were all within ±0.5 mm,which were in line with the IAEA requirements,with only other one being beyond-0.5 mm,not consistent with the IAEA requirements.The differences of film-measured actual widths between each pair and all pairs of leaves were within ±0.75 mm as required by IAEA for 7 accelerators,whereas the other one was outside ± 0.75 mm,not consistent with the IAEA requirements.The standard deviation of film-measured actual width of MCL leaf between each pair and all pairs for 7 accelerators were ≤ 0.3 mm as required by IAEA,whereas the other one was 0.5 mm,not consistent with IAEA requirements.Conclusions The MLC positioning accuracy of a few of medical accelerators in Henan is not qualified.It is of great significance to carry out regular quality examination as well as third-party verification to ensure precise delivery of radiotherapy.
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Objective To develop measurement methodology using film for the positioning accuracy of MLC leaves in IMRT.Methods The solid water phantom of 30 cm x 30 cm was scanned and the scanned images were transferred to TPS for treatment plan formulation.The five MLC strip picket fence pattern was formed by MLC leaves,each 3.0 cm long × 6.0 mm wide.The separation between strip and strip is 3.0 cm.SAD is 100 cm at dmax for 6 MV X-ray,with 250 MU per MLC strip.EBT2 radiochomic film was put on the phantom for delivery of IMRT,for each MLC strip.The present study focused on 30 accelerators of Varian,Elekta and Siemens designs at 27 hospitals with highly skilled physicists all over Jiangsu,Sichuan,Hubei and Henan provinces.The study was conducted in the same way as used in international multi-radiotherapy center (IMRC).The irradiated films were sent respectively to IAEA dosimetry laboratory and external audit group (EGA) of China for measurement,analysis and calculation.Results According to IAEA requirements,the differenc of film-measured and TPS-planned of MLC leaf position for each strip should be within ±0.5 mm.China had participated in the research of IMRC,with the result of 0.3,0.2,0.0,-0.1,and-0.2 mm,respectively.For 30 accelerators in four provinces involved in the study,the IAEA's verification results of MLC leaf position were within 0.6-1.0 mm for 5 accelerators and within ± 0.5 mm for other 25 ones.Whereas the verification results of EAG were within 0.6-1.0 mm for 6 accelerators and within ±0.5 mm for other 24 ones.According to IAEA requirements,the film-measured MLC leaf position deviation for each pair of leaves and average all pairs of leaves should be within ±0.5 mm.China had participated in IMRC's research,with the measured result being 0.04 mm.The verification result of EGA for 30 accelerators showed the measured MLC leaf position deviations were all ＜0.3 mm per strip,consistent with IAEA requirements.The IAEA's result showed the measured deviations of MLC leaf position for 29 accelerators were within ±0.5 mm,with only other one being-0.7 mm not consistent with the IAEA requirements.As required by IAEA,the difference of film-measured difference of MLC opening width should be within ±0.75 mm between each pair and average all pairs of leaves.China's result in research of IMRC showed the difference of minimum width to mean width was-0.2 mm whereas the difference of maximum width to mean width was 0.4 mm.For 30 accelerators involved in IAEA'verification study,the measured result shown that the difference between maximum and average of filmmeasured of MLC leaf width,and between minmum and average,were within ± 0.75 mm for 24 accelerators,in line with the IAEA requirements.For other 6 ones,the values were beyond ±0.75 mm,not in line with the IAEA requirements.For the verification result of EAG,the difference between maximum and average widths and between minmum and average widths for 25 accelerators were within ±0.75 mm as required by IAEA,whereas for other 5 ones the value were beyond ±0.75 mm,not consistent with IAEA requirements.The standard deviation of film-measured MLC opening width between each pair and average all pairs should be within 0.3 mm as required by IAEA.China's IMRC result was 0.12 mm.The verification result of IAEA shown the standard deviation of MLC opening position were ＜0.3 mm for 26 accelerators and ＞ 0.3 mm for other 4 accelerators.EAG verification result were the same as IAEA result.Conclusions The method using radiochromic film for measuring accuracy of MLC leaf position is convenient and practicable as a quality audit.It is suitable for quality verification in medical institutions owing to easy to post and repeated measurements.
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Objective To validate the absorbed dose and two-dimensional dose distribution from photon beam by using Thermoluminescent dosimeter (TLD) and film for intensity modulated radiation therapy (IMRT).Methods A total of 8 medical accelerators were selected among 5 third-grade first-class hospitals using non-probabilistic sampling method in Henan province.TLDs were put into polytetrafluoroethylene solid phantom with size of 5 cm × 15 cm × 15 cm provided by IAEA.After CT scanning,the radiotherapeutic plans were formulated through image transmission to the treatment planning system (TPS).The IMRT plan was implemented for measurement of TLD-absorbed doses under the conditions of 5 cm × 5 cm field,90 cm SSD,10 cm depth,6 MV photon beam and 6 Gy absorbed dose and corresponding measurement unit (MU).The 25 cm × 25 cm film-absorbed dose measurement was made in the same manner as TLD under the conditions of 30 cm × 30 cm size,20 cm thickness,95 cm SSD and 5 cm depth.Results Of eight accelerators,the requirements can be met for 7 accelerators with respect to the relative deviation of TLD absorbed dose except 1.For film,relative deviations were all consistent with the requirements.The passing rate of two-dimensional dose distribution was in line with the requirements for 7 accelerators except 1.Conclusions TLD and film can be used to check the MLC field absorbed dose and two-dimensional dose distribution.This methodis simple,easy to operate and suitable for the implementation of IMRT quality control in hospitals in Henan province.
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Objective To observe the changes of serum iron in patients with bronchopneumonia (bacterial pneumonia,mycoplasmal pneumonia) before and after treatment,and to discuss whether it can be used as an indicator of infection.Methods Forty cases with bacterial pneumonia and 41 cases with mycoplasmal pneumonia were recruited.The serum iron levels before and after treatment in bacterial pneumonia group and mycoplasmal pneumonia group were compared and analyzed.The correlation between white blood cell count,percentage of neutrophils,serum C-reactive protein (CRP) levels and the serum iron levels before treatment,and changes of the serum iron before and after treatment were analyzed.Results The level of serum iron after treatment in the bacterial pneumonia group [(16.28 ±5.81) μmol/L] was significantly higher than that before treatment [(4.83 ± 2.12) μ mol/L] (t =-11.19,P＜0.001).The level of serum iron after treatment in the mycoplasmal pneumonia group [(15.17 ±5.31) μmoL/L] was also significantly higher than that before treatment [(4.77 ± 1.99) μmol/L] (t =-11.29,P ＜0.001).The serum iron levels between the two groups before and after treatment had no statistically significant differences (t =0.135,0.898,P =0.893,0.373).There was no correlation between white blood cell count,percentage of neutrophils,CRP and serum iron levels before treatment (bacterial pneumonia group:r =-1.87,-0.219,-0.152;mycoplasmal pneumonia group:r =-0.032,-0.302,-0.274) and changes of the serum iron before and after treatment (bacterial pneumonia group:r =0.098,0.062,0.205;mycoplasmal pneumonia group:r =0.01 1,0.171,-0.105,P ＞ 0.05).Conclusion The serum iron level is significantly decreased in children with pulmonary infectious diseases and increased to normal level after anti-infection treatment.Serum iron can not be used as an indicator of infection in children.
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Objective To investigate the public's perception and attitudes on the development of nuclear power, assess their knowledge about nuclear power and radiation, and to build a database on the public's perception for the purpose of providing better public health service, associate technical support and give suggestions for decision-makers.Methods In total of 1 440 local residents who live within 30 kilometers of a proposed nuclear power were chosen for in-person interviews.Questionnaires comprised of 49 questions designed to assess the public's knowledge of radiation and nuclear power, their attitudes to the development of nuclear power, their evaluation of local government and their informational environment.ANOVA was used to compare the influence of different factors on cognitive level.Multivariate linear regression was used to analyze the main factors affecting the level of public awareness.Comparison among groups (respondents in this survey vs.other comparable surveys) was conducted using x2 test.Results Of the respondents, 29.7％ and 39.5％ of respondents knew about nuclear power and radiation, respectively, 24.2％ supported the construction of a nuclear power plant in their own area, which was lower than the average national support for construction of nuclear power plants (29.0％) (x2 =8.71 ,P ＜ 0.05).When queried about safety cncerns 36.8％ of respondents worried about the safety of nuclear power plant and 78.5％ of respondents were afraid of the damage to their health, while 34.1％ of respondents held the belief that the nuclear power plant could bring harmful effect even under normal operation.Regarding the informational environment, 90.0％ of the respondents could not or barely got access to knowledge on nuclear power plants, 71.1％ hoped to acquire the knowledge on nuclear power plants, 48.4％ hoped to acquire this knowledge by television programs, and 62.4％ mostly trusted information given by experts from universities or institutes.In comparison to other findings acquired in similar surveys on the Tianwan and Qinshan nuclear power plants before the Fukushima accident, the findings indicated that safety assessment of nuclear power plant were lower (x2 =20.49,56.96, P ＜ 0.05).Conclusions The public's knowledge level on nuclear power and radiation directly influenced their attitude on nuclear power.The related agencies should strengthen publicity and education in order to increase the public's knowledge on nuclear power and radiation.The communication platform between the related agencies and the public should be established.Active and continued risk communication should be carried out to increase public acceptance of nuclear power.
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Objective To investigate muli-leaf collimator (MLC)-defined small field output factors calculated by the treatment planning system (TPS), and to study the measuring method of small field output factors verified by 0.015 cc PinPoint ionization chamber.Methods Eight medical accelerators for intensity-modulated radiation therapy (IMRT) were investigated in Henan province, and TPS-calculated output factors for various small fields (6 cm ×6 cm,4 cm ×4 cm,3 cm ×3 cm and 2 cm ×2 cm) were compared with published values recommended by IAEA.If the relative deviation was more than ± 3％ for the 2 cm ×2 cm field size and ±2％ for the fields of 6 cm ×6 cm, 4 cm ×4 cm and 3 cm ×3 cm, which was beyond the scope of IAEA allowed, the output factors will be measured and verified using 0.015 cc PinPoint ionization chamber and Unidos electrometer.Results TPS-calculated small field output factors for eight medical accelerators were compared with published values.The relative deviation of small field output factors for five pieces of equipment, which accounted for 62.5％ of the total, met the IAEA's requirement, while the other three, which accounted for 37.5％ of the total, did not.After measuring with PinPoint ionization chamber, the results from only three pieces of equipment met minimum IAEA's requirement.Conclusions MLC-defined small field output factors calculated by TPS for some medical accelerators in Henan need to be measured and corrected using micro-ionization chamber, and the measured values could be taken as the basis of radiation treatment planning.
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Objective To verify the reliability of radiotherapy dosimetric parameters in reference and non-reference conditions using thermoluminescent dosimeters (TLDs).Methods Using the established TLD method,the dose variations with different radiation field sizes and 45 ° wedge plate were verified for 10 photon beams of 6 MV,together with dosimetric parameters at the point of maximum axial dose for 4 electron beams of 9 MeV under reference and non-reference conditions.Comparisons were made between TLD results and finger ionization chamber results.Results The average relative deviation,for 6 MV photon beams,between TLD results and finger ionization chamber measurements was 4.7％,within ± 7％ as required by the IAEA.The average relative deviation,for 9 MeV electron beam,between TLD results and plane parallel ionization chamber measurements was 2.4 ％,not beyond ± 5％ permitted by IAEA.Conclusions Using TLD method to verify the radiotherapy dosimetric parameters in reference and non-reference conditions was reliable,simple and feasible.
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Objective To assess the dose reduction potential of adaptive statistical iterative reconstruction(ASiR)and model-based iterative reconstruction(MBIR)in pelvic CT with a standard male phantom.Methods A Fluke Biomedical RANDO standard male phantom was scanned with discovery CT750 HD using different tube currents.CT images were reconstructed with FBP,50％ASiR and MBIR.The CT value,the image noise and the contrast-to-noise ratio(CNR)for the sacral vertebra relative to muscle were measured.The volume CT dose indexes(CTDIvo1)and dose-length product(DLP)were recorded.Results Compared with FBP,using 50％ASiR and MBIR had significant reduced image noise and greater CNR.The effective minimal tube currents for displaying sacral vertebra were 250 mA(FBP),180 mA(50％ASiR),and 100 mA(MBIR).With the similar image quality using FBP,the dose was reduced by 28.0％ and 59.9％ using 50％ASiR and MBIR,respectively.Conclusions Using advanced iterative algorithms can reduce image noise,improve CNR,and reduce the radiation dose in pelvic CT examination.
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In order to analyze the image noise effect on the results of Gamma knife dosimetry parameter test, we tested the dosimetry parameters of the Gamma knives according to GBZ 168-2005. Radiological protection standards of X (gamma)-ray stereotactic radiosurgery for head treatment. Dose analysis software was applied to examine the testing film before and after image denoising, and SPSS 11.0 software was used for statistical analysis. The results showed that there was a significant difference in the results of the maximum deviation between radiation field size and its nominal value (t = 7.600, P < 0.01) and the radiation field's penumbra region width of collimators also had significantly different sizes (t = 5.334, P < 0.01) before and after image denoising. This study indicated that the image noise could influence the results of testing Gamma knife dosimetry parameters, so as to cause deviations.
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Humans , Algorithms , Artifacts , Gamma Rays , Head , General Surgery , Radiometry , Radiosurgery , Radiotherapy Planning, Computer-Assisted , Methods , Stereotaxic TechniquesABSTRACT
Objective To compare the analytical result of different kinds of film dose analysis software for the same gamma knife,analyze the reasons of difference caused,and explore the measurements and means for quality control and quality assurance during testing gamma knife and analyzing its result.Methods To test the Moon Deity gamma knife with Kodak EDR2 film and γ-Star gamma knife with GAFCHROMIC(R) EBT film,respectively.All the validation films are scanned to proper imagine format for dose analysis software by EPSON PERFECTION V750 PRO scanner.Then imagines of Moon Deity gamma knife are analyzed with Robot Knife Adjuvant 1.09 and Fas-09 1.0,and imagines of γ-Star gamma knife with Fas-09 and MATLAB 7.0.Results There is no significant difference in the maximum deviation of radiation field size ( Full Width at Half Maximum,FWHM) and its nominal value between Robot Knife Adjuvant and Fas-09 for Moon Deity gamma knife (t = -2.133,P ＞0.05).The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicated that the differences are significant (t = - 8.154,P ＜ 0.05 ).There is no significant difference in the maximum deviation of FWHM and its nominal value between Fas-09 and MATLAB for γ-Star gamma knife ( t = - 1.384,P ＞0.05 ).However,following national standards,analysis of φ4 mm width of collimators can obtain different results according to the two kinds software,and the result of Fas-09 is not qualified while MATLAB is qualified.The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicates that the differences are significant ( t = 3.074,P ＜ 0.05 ).The imagines are processed with Fas-09.The analysis of imagine in the pre-and the post-processing indicates that there is no significant difference in the maximum deviation of FWHM and its nominal value ( t = 0.647,P ＞ 0.05 ),and the analytical result of the radiation field' s penumbra region width indicates that there is no significant difference as well ( t = -0.627,P ＞ 0.05 ).Conclusion The study shows that different kinds of film dose analysis software may have some differences in analysis of the same gamma knife validation film,and the results may lead to the different decisions in accordance with national standard.
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Objective To investigate radiation risk perception and nuclear acceptance after the 60Co stuck source incident in June 2009 in Qixian County,Henan Province.Methods From March to April 2010,23 hamlets and 2 schools from 5 towns in Qixian County were selected,while 3 hamlets and 2 schools from 3 towns were used as control in Huixian County,1 35 km away where no any impact of the incident was found.Face-to-face questionnaire survey was conducted among three groups including mass public,elite public(representatives of public opinion,such as physicians,teachers,govemmental officials,administrative personnel,private entrepreneurs),and middie school students(the third grade students in junior middle schools and the first grade students in senior middle schools).Results A total of 1 340 valid questionnaires were collected.The public knowledge levels about radiation and nuclear power were low among all groups in two areas and public knowledge levels in Qixian County were higher than those in Huixian County.In both areas.the knowledge levels of the students were higher tIIan those among the elite public,and that among the general public were the lowest.The knowledge levels of males and those with higher educational levels were higher than those of females and those with lower educational levels.More than 40.0% of the respondents supported the idea to build nuclear power plants in China.but only a small part of them supported to build nuclear power plants in their own areas.The percentages of opponents against local nuclear power plant construction were especially higher among the students and those with higher educational levels.More than 60% of the mass public and elite public believed the explanation of the government.More than 80% of the respondents held negative attitudes towards the performance of the Qixian County Government in dealing with this incident.The student gave the lowest evaluation of the credibility and the specific performance of the local government,whereas the elite public placed themselves between the students and the mass public.The reasons why the local people left their homes to evade risk included rumors(67.2%),lack of radiation knowledge(61.9%),group psychology(59.2%),and failure of the government to inform the truth to the public in time(42.3%).Conclusions The public still fails to know enough about radiation and nuclear power.Although they trust the government,they are dissatisfied with the performance of the local government in dealing with the incident.The negative evaluation of the students is worth concerning.
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Objective To study the influence of nursing interventin on compliance of patients with allergic rhinitis undergoing immunotherapy.Methods Patients with allergic rhinitis undergoing immunotherapy from October of 2003 to October of 2005 and from Novermber 2005 to August 2007 were named the control group and test group respectively.Only the test group received nursing intervention.The compliance of the patients was investigated with subsequent cause analysis.The compliance de-gree and its influencing factors in the two groups were compared.Results The complete complianceof the test group was 80.5%,which was statistically different from that of the control group(68.9%,P<0.01).The difference between adult patients of the two groups was also evidently different(P<0.05).But the difference between children patients of the two groups was not evidently different(P>0.05).Statistical difference existed between children and adult patients in the control group as well as in the testgroup(P<0.01).The uncontrollable factors in the test group reduced while the controllable factors increased.Conclusion The nursing intervention could improved patients compliance with immunotherapy in that it reduced the uncontrollable factors among the reasons causing uncompliance.It worth widely being applied in clinic.