Skin entrance radiation dose in an interventional radiology procedure

Monitoring of skin entrance radiation exposure in lengthy interventional procedures has been recommended because of the potential for skin injury. Fluoroscopy duration and dose-area product (DAP) are readily available real-time measurements. It would be of interest to study the correlation of these parameters and skin entrance radiation. Twenty neurological interventional procedures performed through the aortic arch were monitored. Two pieces of GafChromic XR Type R film were placed between the patient and the examination table. An observer recorded the fluoroscopy duration and DAP for each phase of the procedure. Each film was scanned post-procedure in RBG mode, and then the image was analyzed for peak skin entrance radiation dose (in air kerma). All DAP values were corrected according to a calibration with an ion chamber. With the DAP values for the respective phases of a procedure, the effective dose in a Reference Man was calculated. For these twenty cases, the means and standard deviations were 17.2+/-6.4 min for x ray on-time, 256+/-65 Gy cm (-2) for DAP, 94+/-34 cGy for peak skin entrance dose in air kerma, and 19.2+/-5.0 mSv for effective dose, respectively. The peak skin entrance dose was correlated to fluoroscopy duration, DAP, and effective dose with the r(2)-values of 0.48, 0.46, and 0.09, respectively. The correlation with DAP or fluoroscopy duration was not sufficiently strong to infer skin entrance dose from either of these parameters. Therefore, skin entrance dose should be determined directly.     

Radiation doses to patients from extracorporeal shock wave lithotripsy

The aim of this study was to determine the radiation doses to patients during extracorporeal shock wave lithotripsy (ESWL) and compare them with the available bibliographical data. In this method localization of the renal stones is attained by the use of fluoroscopy, and thus ESWL is included among those medical practices associated with patient radiation exposure. The entrance surface dose was measured using 3-4 thermoluminescent dosimeters positioned on the patients' backs at the entrance surfaces of the two x-ray beams for 50 ESWL procedures. Fluoroscopy time and number of spot films were also recorded. The average entrance surface dose at the patient's side with the renal stone was estimated to be 76.5 mGy for the oblique x-ray beam and 44.5 mGy for the PA x-ray beam. The mean fluoroscopy time was 204 s while 4 spot films were acquired on average. The mean effective dose (E) was estimated as 1.63 mSv per patient. The mean entrance surface dose values recorded in this study are comparable to but smaller than the values reported in the literature for ESWL, while the mean fluoroscopy time is within the range of values reported by other authors. On the other hand, the estimated E value is relatively higher compared to the corresponding values given in the literature based on patient measurements. However, it is comparable to recent published data acquired using extended measurements in an anthropomorphic phantom.     

Patient doses from neuroradiological procedures

Patient doses have been determined for a sample of 20 patients in a hospital department undergoing various interventional neuroradiological procedures. Skin entrance dose, dose-area product and effective dose have been estimated. Effective dose was estimated from published conversion factors. The highest dose on the patients body was recorded as the maximum skin entrance dose. The maximum skin entrance dose varied from 0.2 to 2.3 Gy. The largest maximum skin entrance dose is similar to the threshold for skin injuries (erythema). The effective dose varied from 2 to 34 mSv. The results of this study are compared with the results of other studies on radiation dose to patients from neuroradiological procedures.     

Nation-wide survey on radiation doses in diagnostic and interventional radiology in Switzerland in 1998

A nation-wide survey on radiation doses in diagnostic and interventional radiology was conducted in Switzerland in 1998 aiming at establishing their collective radiological impact on the Swiss population. The study consisted on the one hand of surveying the frequency of more than 250 types of examinations, covering conventional radiology, mammography, fluoroscopy, angiography, interventional radiology, CT, bone densitometry, conventional tomography and dental radiology. On the other hand, for each type of examination the associated patient dose was established by modeling. The results of this study show that about 9.5 million diagnostic and interventional examinations are performed annually in Switzerland (1.34 per caput) and that the associated annual collective dose is of the order of 7100 person.Sv (1.0 mSv per caput). Switzerland is similar to other European countries in terms of the frequency of examinations and the collective dose.     

2011年天津市部分放射工作人员外照射个人剂量监测结果分析

目的了解2011年天津市部分放射工作人员在职业活动中受到的外照射个人剂量情况。为提高放射防护管理工作质量提供建议。方法根据相关标准的要求,采用热释光个人剂量监测的方法监测放射工作人员外照射个人剂量当量。结果放射工作人员的年平均有效剂量为0．355mSv,医学应用的年平均有效剂量为0．370mSv,工业应用的年平均有效剂量为0．278mSv。98．2％的放射工作人员年有效剂量低于5mSv。结论所调查的2011年天津市的放射工作人员的工作环境的放射防护措施能够有效地控制辐射水平。但需要进一步加强,对年有效剂量超过5mSv的工作人员的管理。     

2016年南通市放射工作人员外照射个人剂量监测结果

目的 了解南通市放射工作人员职业外照射的剂量水平及分布情况,评价放射工作人员职业危害及防护效果,为放射防护管理工作提供科学依据。方法 使用RGD-3D热释光剂量仪对放射工作人员进行外照射个人剂量当量H_P（10）监测,职业类别包括诊断放射学、介入放射学、核医学、牙科放射学、放射治疗、工业应用等,采用全国放射卫生信息平台个人监测管理系统进行数据汇总统计。结果 南通市放射工作人员外照射人均年有效剂量为0.273 mSv/a,所有监测人员的年有效剂量均小于年剂量限值20 mSv,集体有效剂量为0.570人·Sv,人均年有效剂量以介入放射学（0.375 mSv/a）稍高,其次为核医学（0.316 mSv/a）,人数最多的诊断放射学为0.271 mSv/a,其余职业类别年有效剂量值均在较低水平;不同地区放射工作人员平均年有效剂量相差不大,人均年有效剂量海安县（0.418 mSv/a）较其他地区稍高;二甲医院以下医疗单位监测剂量值（0.361 mSv/a）要高于二甲医院及以上医疗单位（0.182 mSv/a）和工业企业（0.143 mSv/a）。结论 2016年南通市放射工作人员年有效剂量均处于较低水平,我市放射工作人员的放射防护条件良好,工作环境安全。     

2010-2016年乌鲁木齐市某三甲医院职业外照射个人剂量监测结果分析

目的 调查2010-2016年乌鲁木齐市某三甲医院放射工作人员职业性外照射个人剂量监测水平,分析不同职业类别工作人员的剂量分布情况。方法 按照《职业性外照射个人监测规范》（GBZ 128-2016）的方法,采用热释光个人剂量测量方法对该院放射工作人员进行职业性外照射个人监测,并对2010-2016年监测结果进行统计分析。结果 2010-2016年乌鲁木齐市某三甲医院的放射工作人员人均年有效剂量分别为：1.02、1.02、1.01、0.56、0.32、0.39、0.41 mSv,7年平均剂量为0.56 mSv;7年间监测人数不断增加,人均年有效剂量呈下降趋势,并在一个水平相对稳定。结论 该院放射工作人员职业性外照射人均年有效剂量均在国家标准规定的个人剂量限值之内,放射工作人员的工作环境是安全的。但核医学和介入放射学剂量应是控制的重点。     

2016年滦南县放射工作人员外照射个人剂量及放射诊疗设备现状分析

目的 了解滦南县放射工作人员外照射个人剂量水平及放射诊疗设备现状,为评价放射工作场所防护现状提供依据。方法 按照《职业性外照射个人监测规范》（GBZ 128-2016）的要求,采用热释光剂量法对滦南县所有医疗卫生机构放射工作人员外照射进行监测。结果 滦南县共有放射诊疗单位30家,放射工作人员146人,实际监测人员131人,监测率89.73%。131人的集体年剂量当量为51.97 mSv人,人均年剂量当量为0.40 mSv。其中128人年剂量当量低于2 mSv,3人年剂量当量在2~5 mSv之间,占2.29%,年剂量当量值均无超过5 mSv。县级医院人均年剂量当量为0.36 mSv,乡镇级医院人均年剂量当量为0.44 mSv,牙科门诊人均年剂量当量为0.34 mSv,个体诊所人均年剂量当量为0.31 mSv。放射工作人员中以普通放射工作人员为主,共计97人,占74.05%,人均年剂量当量0.38 mSv;从事CT人员19人,人均年剂量当量0.50 mSv;从事介入人员9人,人均年剂量当量0.24 mSv;专职牙科人员4人,人均年剂量当量0.34 mSv;放射治疗2人,人均年剂量当量1.04 mSv。经比较,放射治疗与其他放射工种的人均年剂量当量差异有统计学意义（P<0.05）。结论 全县放射工作人员人均年有效剂量均远远低于国家标准限值,表明放射职业环境相对安全。     

Measurement of entrance skin dose and estimation of organ dose during pediatric chest radiography

Entrance skin dose (ESD) was measured to calculate the organ doses from the anteroposterior (AP) and posteroanterior (PA) chest x-ray projections for pediatric patients in an Indian hospital. High sensitivity tissue-equivalent thermoluminescent dosimeters (TLD, LiF: Mg, Cu, P chips) were used for measuring entrance skin dose. The respective organ doses were calculated using the Monte Carlo method (MCNP 3.1) to simulate the examination set-up and a three-dimensional mathematical phantom for representing an average 5-y-old Indian child. Using this method, conversion coefficients were derived for translating the measured ESD to organ doses. The average measured ESDs for the chest AP and PA projections were 0.305 mGy and 0.171 mGy, respectively. The average calculated organ doses in the AP and the PA projections were 0.196 and 0.086 mSv for the thyroid, 0.167 and 0.045 mSv for the trachea, 0.078 and 0.043 mSv for the lungs, 0.110 and 0.013 mSv for the liver, 0.002 and 0.016 mSv for the bone marrow, 0.024 and 0.002 mSv for the kidneys, and 0.109 and 0.023 mSv for the heart, respectively. The ESD and organ doses can be reduced significantly with the proper radiological technique. According to these results, the chest PA projection should be preferred over the AP projection in pediatric patients. The estimated organ doses for the chest AP and PA projections can be used for the estimation of the associated risk.     

通过剂量面积乘积估算内镜逆行胰胆管造影患者的有效剂量

目的 估算内镜逆行胰胆管造影（ERCP）操作中患者的辐射剂量水平,为制定介入放射学中患者的防护标准提供科学依据。方法 以ERCP手术调查的相关参数（透视时间、点片张数及设备相关参数）为条件,测量剂量面积乘积（DAP）,并利用测量的DAP值,通过基于蒙特卡罗（Monte Carlo）计算方法剂量估算软件（Ref Dose）,估算出患者的有效剂量（Effective Dose,E）。结果 按照操作难易程度分组,患者有效剂量分别为：ERCP操作复杂组4.448 mSv、ERCP操作中等组0.715 mSv、ERCP操作简单组0.247 mSv。结论 患者有效剂量的大小与3个剂量组中透视时间及DAP值呈正相关关系。ERCP手术中,在不影响临床效果的情况下,应尽可能缩短透视时间、减少摄片帧数、缩小照射野,从而尽可能降低患者的有效剂量。     

广州市某三甲医院放射工作人员受照辐射剂量分析

目的掌握广州市某三甲医疗机构放射工作人员外照射个人剂量情况,为放射卫生防护管理提供科学依据。 方法采用热释光剂量测量方法,对2020年广州市某三甲医疗机构的放射工作人员进行个人剂量监测,分析监测数据。 结果共计182人参与个人剂量监测,其中X射线影像诊断工作人员占84.6%（154/182）,介入放射学工作人员占15.4%（28/182）。四期合计监测566人次,其中X射线影像诊断工作人员470人次,介入放射学工作人员96人次。个人剂量年度监测期数满四期的人员占监测总人数的55.5%（101/182）。单个周期有效剂量在调查水平（＞1.25 mSv）范围的有3人,分别为1.56 mSv、1.32 mSv、2.59 mSv。X射线影像诊断、介入放射学人均年有效剂量分别为0.42（0.27,0.93）mSv /a、0.59（0.17,0.78）mSv /a,两者相比差异无统计学意义（P＞0.05）。铅衣内、外人均年有效剂量分别为0.40（0.16,0.81）mSv /a、0.72（0.29,0.91）mSv/a,差异有统计学意义（Z=-4.395,P＜0.05）。介入放射学工作人员铅衣外剂量大于内剂量的情况占70.8%（68/96）;铅衣内剂量大于外剂量的情况占29.2%（28/96）。 结论该医院应进一步加强放射工作人员管理,降低辐射受照剂量,防止放射性疾病的发生。     

Doses to patients from diagnostic radiology in France

Reported here are results of a 1982 national survey in France to establish the collective effective dose equivalent associated with the main types of radiological examinations practiced annually in this country (except nuclear medicine, C.T. scans, dental radiology and mass chest screening). This report describes the methodology followed in achieving dose measurements either on an anthropomorphic phantom or directly on the patient, and it highlights the importance of the radiological procedures (number of x-ray films, fluoroscopy screening time, etc.) on the patient organ doses. The estimated collective effective dose equivalent associated with these radiological practices is 86,000 person-Sv, i.e., an individual effective dose equivalent of 1.58 mSv y-1; the genetically significant dose figure is 0.29 mSv and the collective red bone marrow dose due to 45 million x-ray exams practiced in France (1982) is 40,300 person-Sv, i.e. 0.74 mSv per inhabitant.     

重庆市介入放射工作人员个人剂量监测情况分析

目的 了解重庆市介入放射工作人员个人剂量监测现状及结果,为制定职业性放射性疾病防治政策和修订国家放射卫生标准提供科学依据。 方法 通过重庆市疾病预防控制中心个人剂量监测系统,收集2016—2020年重庆市介入放射工作人员个人剂量监测资料,χ²检验比较个人剂量监测数据和防护用品配置数据的差异,Kruskal-Wallis H检验比较介入放射工作人员不同年份、不同职业类别的剂量监测结果的差异。 结果 本次调查共计5 791人,19 493人次,5年间介入放射工作人员人均年有效剂量为0.36 mSv,监测年剂量超过1 mSv的介入人员占总监测人数的比值(NR₁)为11.93%,监测年剂量超过5 mSv的介入人员占总监测人数的比值(NR₅)为0.48%; 不同年份重庆市介入人员人均年有效剂量呈现总体下降趋势,差异有统计学意义(χ²=1 135.046,P<0.001); 介入防护用品三级医院配置率均高于二级医院配置率,其中防护吊帘(χ²=6.813,P<0.05)差异有统计学意义; 不同职业类别的年有效剂量由高到低依次为介入放射学、核医学和放射治疗,分别为0.36 mSv、0.34 mSv和0.31 mSv,差异有统计学意义(χ²=228.611,P<0.001); 眼晶体监测估算年有效剂量超过20 mSv的人数达到调查对象的6.80%。结论 重庆市介入放射工作人员人均年有效剂量逐年下降并保持在相对较低的水平,符合国家标准要求。建议加强防护用品的配置和使用,长期开展眼晶体剂量监测。     

HSE performance tests for dosimetry services.

In the United Kingdom a dosimetry service that measures and assesses whole-body or part-body doses arising from external radiation must successfully complete a performance test. Results of the performance tests for routine whole-body, routine extremity/skin and special accident dosimetry, carried out over the past six years by the AEA Technology Calibration Service at Winfrith, and DRaStaC, the AWE Calibration Service at Aldermaston, are presented. The test involves irradiating groups of dosemeters to known doses of gamma radiation and determining the bias and relative standard deviations for each dose group. The results are compared with the pass criteria specified by the UK Health and Safety Executive. For routine whole-body dosimetry, both the film badge and thermoluminescent dosemeter (TLD) perform adequately for irradiations between 0.6 and 30 mSv. For higher doses up to 250 mSv, where the slow emulsion of the film is used, the film badge shows poorer performance with a tendency to overestimate the dose. For routine extremity/skin dosimetry there is a wider spread of relative standard deviation results than is seen for routine whole-body dosimetry. This is to be expected since the results will include dosemeters that are based on 'disposable' TLDs and ones based on lithium fluoride powder in sachets. For special accident dosimetry the dosemeters are tested between 0.26 and 6 Gy. For the highest dose group the film badge invariably underestimates the true dose, whereas the TLD has a tendency to overestimate it.     

Medical exposure of the population from diagnostic use of ionizing radiation in luxembourg between 1994 and 2002

A national evaluation on radiation doses from diagnostic procedures (x rays and nuclear medicine) was conducted in Luxembourg for the period 1994-2002 aiming at the estimation of the annual collective dose. The calculations were based on a survey of frequencies of more than 250 types of radiological examinations and included more than 425,000 patients. This evaluation ensured the practical implementation of Article 12 of the European Directive 97/43/EURATOM, which obliges the Member States to determinate the population dose from medical exposure. The results show an increase of the annual effective dose per capita from 1.59 mSv in 1994 to 1.98 mSv in 2002. The impact of computed tomography to dose received from medical use of radiation has dramatically increased in this time period. Luxembourg has one of the highest computed tomography examination rates compared to other health care level I countries. The following measures to minimize medical exposures were proposed in the study: medical physicists should have a more central role to play in patient dosimetry in interventional and diagnostic radiology, especially concerning computed tomography. Also, the implementation of an electronic "X-ray patient card" for all irradiated patients--except dental--and the use of the European referral criteria that give guidance and recommend investigations in various clinical settings can both help to decrease medical radiation exposures.     

天津市宝坻区放射工作人员外照射个人剂量水平分析

目的了解天津市宝坻区放射工作人员外照射个人剂量水平,为放射防护提供科学依据。方法采用热释光剂量测量方法对宝坻区2007—2011年放射工作人员的个人剂量进行检测分析。结果宝坻区5年内监测放射工作人员626人次,人均年有效剂量均数为0.57 mSv/a,每年低于5 mSv的人员占当年总监测人数的98.7%以上;不同工种之间,以介入治疗和放射治疗较高,分别为1.74和1.00 mSv/a。结论该区放射工作人员个人剂量人均剂量水平较低,但应将从事介入治疗和放射治疗的工作人员做为防护的重点。     

Overview of contemporary interventional fluoroscopy procedures

Interventional fluoroscopy procedures are increasingly important in medical practice. As new procedures are introduced and validated, they tend to replace the equivalent surgical procedure. There is wide variation in patient dose, both among procedures and for a specific procedure. Stochastic risk is present, but interventional fluoroscopy procedures may also present deterministic risk. Radiation risk/benefit analyses are different for interventional fluoroscopy procedures than they are for diagnostic imaging procedures. The radiation risk component of an interventional fluoroscopy procedure is substantially less than the other procedural risks, and there is always clear and measurable benefit to the patient from a successful procedure. Optimizing patient dose will require both improvements in equipment technology and greater attention from regulators, accrediting bodies and medical organizations. Ensuring adequate operator training is essential.     

低剂量电离辐射对放射工作人员血液指标的影响

  目的  探讨低剂量电离辐射对放射工作人员血液指标的影响。
  方法  选取武汉市某医院从事X射线影像诊断和介入放射学的工作人员共211名作为研究对象,收集其2017年个人外照射剂量和2018年初在岗期间的职业健康检查资料。按工种将研究对象分成X射线影像诊断组（104人）和介入放射学组（107人）,采用独立样本t检验对两组人群血常规及血生化指标进行比较,采用线性回归模型分析辐射暴露剂量和血常规及生化指标的关系。
  结果  介入放射学组个人年剂量均值[（0.16±0.21）mSv]高于X射线影像诊断组[（0.09±0.07）mSv]（P < 0.01）,介入放射学组的肌酐（Cr）值[（81.00±15.43）μmol/L]高于X射线影像组[（73.18±13.31）μmol/L]（P < 0.05）,其他血液指标差异无统计学意义（P > 0.05）。多元线性回归分析发现年剂量每增加1个单位,研究对象中淋巴细胞（LYM）计数降低0.73个单位（P < 0.05）。未发现血常规和血生化其他指标与年剂量存在关联关系。
  结论  低剂量电离辐射对放射工作人员外周血淋巴细胞计数、Cr值存在一定影响。
     

郑州市某医疗机构放射工作人员外照射个人剂量水平调查

目的 调查医疗机构放射工作人员职业外照射个人剂量水平。 方法 选择郑州市职业病防治院介入放射、核医学、放射治疗和放射影像诊断科工作人员,按所在的科室分为4组,对2008-2012年职业外照射个人剂量水平进行检测并作分析。 结果 从事放射工作人员的人均年有效剂量没有超过国家限值,2008-2012年该医疗机构放射工作人员年均个人有效剂量中位数分别为0.46、0.35、0.32、0.28、0.26 mSv/a,有逐年下降的趋势(r=10.38,P < 0.05);不同岗位工作人员年均有效剂量值不同,其中介入放射岗位个人剂量水平高于其他3组(t=0.876、0.532、0.728,P < 0.05)。 结论 该医疗机构介入放射工作人员人均有效剂量较高,应加强对从事放射工作人员,尤其是对介入放射学工作人员的放射防护和防护知识的培训。     

Occupational radiation doses to operators performing cardiac catheterization procedures

Cardiac catheterization procedures using fluoroscopy reduce patient morbidity and mortality compared to operative procedures. These diagnostic and therapeutic procedures require radiation exposure to patients and physicians. The objectives of the present investigation were to provide a systematic comprehensive summary of the reported radiation doses received by operators due to diagnostic or interventional fluoroscopically-guided procedures, to identify the primary factors influencing operator radiation dose, and to evaluate whether there have been temporal changes in the radiation doses received by operators performing these procedures. Using PubMed, we identified all English-language journal articles and other published data reporting radiation exposures to operators from diagnostic or interventional fluoroscopically-guided cardiovascular procedures from the early 1970's through the present. We abstracted the reported radiation doses, dose measurement methods, fluoroscopy system used, operational features, radiation protection features, and other relevant data. We calculated effective doses to operators in each study to facilitate comparisons. The effective doses ranged from 0.02-38.0 microSv for DC (diagnostic catheterizations), 0.17-31.2 microSv for PCI (percutaneous coronary interventions), 0.24-9.6 microSv for ablations, and 0.29-17.4 microSv for pacemaker or intracardiac defibrillator implantations. The ratios of doses between various anatomic sites and the thyroid, measured over protective shields, were 0.9 +/- 1.0 for the eye, 1.0 +/- 1.5 for the trunk, and 1.3 +/- 2.0 for the hand. Generally, radiation dose is higher on the left side of an operator's body, because the operator's left side is closer to the primary beam when standing at the patient's right side. Modest operator dose reductions over time were observed for DC and ablation, primarily due to reduction in patient doses due to decreased fluoroscopy/cineradiography time and dose rate by technology improvement. Doses were not reduced over time for PCI. The increased complexity of medical procedures appears to have offset dose reductions due to improvements in technology. The large variation in operator doses observed for the same type of procedure suggests that optimizing procedure protocols and implementing general use of the most effective types of protective devices and shields may reduce occupational radiation doses to operators. We had considerable difficulty in comparing reported dosimetry results because of significant differences in dosimetric methods used in each study and multiple factors influencing the actual doses received. Better standardization of dosimetric methods will facilitate future analyses aimed at determining how well medical radiation workers are being protected.