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Objective To investigate the awareness, implementation, and application of the Radiation Shielding Specification for Radiotherapy Room, Part 3: Radiotherapy Room of γ-Ray Sources (GBZ/T201.3—2014) by medical institution personnel, to collect problems and recommendations, and to provide a scientific basis for further amendments and implementation of the standard. Methods A questionnaire survey about the awareness, training and application situation and the modification advices of the standard was conducted among practitioners engaged in the production, use, and machine room design related to γ-ray source radiotherapy equipment (collectively referred to as medical institution personnel) in 12 provinces and direct-administered municipalities in China. The questionnaires were collected and a special Excel database was set up for statistical analysis using SPSS 22.0. Results A total of 126 practitioners responded and completed the questionnaire. Approximately 75.4% of respondents indicated that they either “understood” or “understood well” the standard; 42.86% received relevant training; 45.24% and 54.76% indicated that the standard “met” or “basically met” the requirements of detection of γ-ray radiotherapy equipment shielding or design of shielding room. The standard was highly evaluated for suitability. However, the awareness of the standard was inadequate, the rate of training participation was low, and its practical application was limited. Conclusion The standard generally aligns with the requirements for shielding room design in γ-ray radiotherapy. Some revisions should be done according to the current situation of γ-ray radiotherapy.
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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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World Society of Emergency Surgery (WSES), in conjunction with Surgical Infection Society Europe (SIS-E), World Surgical Infection Society (WSIS), American Association for the Surgery of Trauma (AAST), and Global Alliance for Infection in Surgery (GAIS) developed guideline about the management of acute abdomen in immunocompromised patients, which was published in the World Journal of Emergency Surgery (WJES) on August 9, 2021. The guidelines elaborate on the definition, classification, diagnosis and treatment of immunocompromised patients. In addition, based on evidence-based medicine, it provides guidance and suggestion on the management of specific acute abdominal infections in immunocompromised patients, common acute abdominal infections in transplanted patients, patients with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS), as well as perioperative steroid management. An interpretation of the guideline was performed to accomplish a better understanding the current status and recommendations for the management of acute abdominal conditions in immunocompromised patients, and to make forward suggestions on its limitations.
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X-ray imaging is an important method for the diagnosis of corona virus disease(COVID-19), but there is a risk of nosocomial infection during X-ray imaging diagnosis. By analyzing the process of X-ray imaging diagnosis and the possible infection factors in hospital, Jiangsu province took the lead in issuing the Guideline for the nosocomial infection prevention and control of X-ray imaging diagnosis of COVID-19. This guideline clarifies the basic requirements for controlling infections during X-ray imaging diagnosis, the specific measures for staff protection, disinfection of personnel and places, and the protection and disinfection of subjects, which is instructive for field work. It is worth noting that while focusing on controlling infections, the principle of optimal protection for medical exposure cannot be ignored.
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Objective@#To validate the method for measuring the TPV and OAR doses and 2D dose distribution in IMRT through using TLD and radiochromic film.@*Methods@#Eight medical linear accelerators (Valian, Elekta, Siemens) were selected. The polystyrene phantom provided by IAEA was CT scanned and the image obtained was transferred to TPS for formulation of treatment plan, prescription of PTV and OAR doses and calculation of corresponding monitoring unit (MU), IMRT was performed on the phantom using 6 MV X-ray. Irradiated TLDs and films were measured and evaluated at the Secondary Standard Dosimetry Laboratory at the Radiation Safety Institute of Chinese Center for Disease Control and Prevention.@*Results@#According to IAEA requirement, the relative deviations between TLD-measured and TPS-planned doses were within ±7.0% for the prescribed PTV and OAR doses. As measured result, the PTV values for 8 accelerators were in the range of 0.6% to 5.9%, consistent with the IAEA requirements, whereas the OAT values for 8 accelerators were within -0.6% to 7.0%, consistent the requirements. As IAEA required, the 2D dose distribution passing rate of 3 mm/3% should be higher than 90%. The film-measured and TPS-planned values for 8 accelerators were within 90.2% to 100.0%, consistent with the requirements.@*Conclusions@#TLD and radiochromic film are feasible in validating the PTV and OAR doses and the 2D dose distribution pass rate in IMRT. This method can be widely used in quality audit and internal verification in IMRT in medical institutiions on a large scale.
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X-ray imaging is an important method for the diagnosis of corona virus disease(COVID-19), but there is a risk of nosocomial infection during X-ray imaging and diagnosis. By analyzing the process of X-ray imaging & diagnosis and the possible exposure factors in hospital, Jiangsu province took the lead in issuing the guideline for the nosocomial infection prevention and control of COVID-19 during X-ray imaging and diagnosis. This guideline clarifies the basic requirements for controlling infections during X-ray imaging and diagnosis, the specific measures for staff protection, disinfection of personnel and sites, and the protection and disinfection of subjects, which is instructive for on-site work. It is worth noting that while focusing on controlling infections, the principle of optimal protection for medical exposure cannot be ignored.
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Objective To validate the method for measuring the TPV and OAR doses and 2D dose distribution in IMRT through using TLD and radiochromic film.Methods Eight medical linear accelerators (Valian,Elekta,Siemens) were selected.The polystyrene phantom provided by IAEA was CT scanned and the image obtained was transferred to TPS for formulation of treatment plan,prescription of PTV and OAR doses and calculation of corresponding monitoring unit (MU),IMRT was performed on the phantom using 6 MV X-ray.Irradiated TLDs and films were measured and evaluated at the Secondary Standard Dosimetry Laboratory at the Radiation Safety Institute of Chinese Center for Disease Control and Prevention.Results According to IAEA requirement,the relative deviations between TLD-measured and TPS-planned doses were within ±7.0％ for the prescribed PTV and OAR doses.As measured result,the PTV values for 8 accelerators were in the range of 0.6％ to 5.9％,consistent with the IAEA requirements,whereas the OAT values for 8 accelerators were within-0.6％ to 7.0％,consistent the requirements.As IAEA required,the 2D dose distribution passing rate of 3 mm/3％ should be higher than 90％.The filmmeasured and TPS-planned values for 8 accelerators were within 90.2％ to 100.0％,consistent with the requirements.Conclusions TLD and radiochromic film are feasible in validating the PTV and OAR doses and the 2D dose distribution pass rate in IMRT.This method can be widely used in quality audit and internal verification in IMRT in medical institutiions on a large scale.
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Objective To measure the accuracy of multi-leaves collimator (MLC) leaves positions in intensity modulated radiation therapy (IMRT) for verification purpose.Methods Solid water homogeneous phantom with size of 30 cm× 30 cm was scanned by CT scanner.The scanned images were delivered to radiation therapy plan system (TPS) to formulate the therapy plan.The MLC leaves created 5 strips of exposure field,each 3 cm long and 0.6 cm wide.The strip-to-strip distance was 3 cm.With 6 MV X-rays,the SSD was 100 cm at the maximum dose point.The MU per strip was 250 MU.EBT2 radiochromic films each of 25 cm×25 cm were placed on the 30 cm×30 cm homogeneous solid phantom and covered with 1 cm thick solid phantom slabs for delivering of IMRT.Results For 7 of 8 accelerators,the differences of film-measured and TPS-planned MLC leaf position for every fence field were within ± 0.5 mm as required by IAEA,with only other one being-0.6 mm,not consistent with the IAEA requirements.The film-measured position difference between each pair and all pairs of leaves for 8 accelerators were all in line with IAEA's requirements.The film-measured actual width difference between each pair and all pairs of leaves was within ±0.75 mm as required by IAEA for 4 accelerators and outside ±0.75 mm for the other three,not consistent with the IAEA requirements.The standard deviation of film-measured actual width between each pair and all pairs of leaves for 6 accelerators were ≤ 0.3 mm,as required by IAEA,whereas ＞0.3 mm for the other two,not consistent with IAEA requirements.Conclusions The film dosimetric verification of IMRT is an important part of its quality assurance,featuring simple,reliable and highly accurate positioning and can meet measurement requirement.
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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 survey the frequency of medical X-ray diagnosis and estimate the medical exposure levels of Jiangsu province in 2016,so as to be able to improve effectively the protection against medical radiation exposure.Methods All medical institutions in the province were covered in the survey for their basic medical information by means of census method.Frequencies of diagnostic medical X-ray examination were studied using random sampling method in 31 medical institutions.A linear model was established by number of outpatients number of inpatients,number of staff and number of radiation workers to evaluate the medical examination frequency.Results A total of 9 248 pieces of medical X-ray diagnostic equipment by the end of 2016 in Jiangsu province,including 1 110 CT scanners.The total frequencies of diagnostic medical X-ray examination were estimated to be 911.45 examinations per 1 000 population,covering 239.25 per 1 000 for CT scanning.The number of medical X-ray diagnostic equipment increased by a factor of 0.8 while CT scanners by a factor of 3.6 compared to 1999.Medical X-ray diagnostic frequency raised by a factor of 3.2 while CT frequency by a factor of 15.1 compared with previous data.Conclusions The medical X-ray diagnostic frequencies in Jiangsu province was 1.9 times the value given in the UNSCEAR 2008 Report,close to those in some developed European countries.Compared with the study in 2015,the present study has made greater improvement in sampling technique for selection of hospitals and equipment,frequency estimation method and acquisition of influence factors.Estimates of medical X-ray diagnosis frequency are closer to actual level.Further improvement will be needed for the future survey,so as to further study medical exposure levels and to provide basic information for better patient protection.
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Objective To explore the dosimetric verification method for absorbed dose and twodimensional dose distribution generated through multi-leaf collimator in radiotherapy.Methods A total of 8 medical accelerators were selected in Jiangsu province.Under 6 MV X-rays with a 5 cm × 5 cm field,the thermoluminescent dosimeter (TLD) and EBT3 radiochromic film (RCF) were used to audit the values calculated by treatment planning system (TPS).RCF was used to verify two-dimensional dose distribution under the 6 MV MLC beams for intensity modulated radiation therapy (IMRT).Results The relative dose deviation was from-1.4％ to 6.8％ for TLD and from-1.8％ to 7.8％ for RCF,with 7 accelerators meeting with the IAEA deviation requirement of ± 5％.The passing rates of two-dimensional dose distribution were between 73.7％ and 97.0％,with 7 accelerators greater than 90％.Conclusions TLD and RCF are feasible and suitable for large-scale verification of IMRT TPS absorbed dose and twodimensional dose distribution.
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Objective To verify the methodology for auditing dosimetric parameters in reference and non-reference conditions with thermoluminescent dosimeters (TLDs).Methods Under reference and non-reference conditions,the established TLD methods were used to observe the absorbed dose variations with depth,SSD,field size and 45 wedges for 10 photon beams at 5 hospitals.Dosimetric parameters,including doses at Dmax points in axis,on 5 electron beams of 9 MeV were measured.The measurement results were compared between the TLDs and plane parallel ionization chambers.Results For 6 MV photon beams,the relative deviation of between finger ionization chamber method and TLD chips was in the range of-1.7％ to 5.4％ under on-axis non-reference conditions,and-6.3％ to-0.6％ under off-axis non-reference conditions,respectively,all within the range of ≤ ± 7％ as required by the IAEA.The relative deviation between plane parallel chamber and TLD method was-2.3％ to 3.7％,within ± 5％ as required by the IAEA.Conclusions It is convenient and feasible to use TLD method for quality audits of dosimetric parameters in radiotherapy.
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Objective To reduce the radiation dose to children from CT scanning through proper adjustment to milliamps (mAs) and scan lengths with a view to learning the relationship between scanning condition and radiation dose.Methods To compare the differences in main scanning parameters used for head,chest and abdomen at multi-detector CT examination of paediatric patients (＜ 1 year old,1-5 years old,6-10 years old,11-15 years old) at seven hospitals in Jiangsu province.CT dose index (CTDI) and dose-length-product (DLP) were gained by using standard children dose model (diameter 16 cm) under the same scanning conditions.Effective doses (E) at different parts of the body from children CT scanning were estimated after modification by empirical weighting factor.Statistical analyses of mAs,scan lengths and DLP were performed with SPSS 16.0 software.The differences in radiation dose due to the choice of condition of scanning were compared between two typical hospitals.Results The mean values of effective doses to paediatric patients during head,chest and abdomen CT scanning were 2.46,5.69,11.86 mSv,respectively.DLP was correlated positively with mAs and scan length (head,chest and abdomen examination,r =0.81,0.81,0.92,P ＜0.05).Due to higher mAs used,the effective dose from chest and abdomen CT examination among all age groups was higher than that in Germany Galanski research.Due to larger scanning length in abdominal examination among all age groups,effective doses in hospital were the highest.Conclusions Reasonablely reducing the scan length and mAs during CT scanning could lower children's CT radiation risk,while clinical diagnosis is not affected.