Occupational radiation exposure to interventional radiologists: a prospective study.

This study investigates the occupational radiation dose to interventional radiologists and the operator-controlled factors that may affect dose. Thirty interventional radiologists wore radiation badges over and under lead aprons for 2 months and answered a questionnaire. The relationships between dose and caseload, case mix, experience, optional fluoroscopy features, lead apron type, and additional lead shielding were evaluated. Mean projected yearly dose (PYD) over lead was 49.1 mSv (1 mSv = 100 mrem) but was 66.6 mSv for persons performing 1,000 or more cases per year (P = .027). Mean PYD under lead was 0.9 mSv but was 1.3 mSv for persons with 0.5-mm lead coverage and 0.4 mSv for those with 1.0-mm lead coverage (P = .002). No other significant correlation was found. Conclusions are that caseload and apron thickness are the primary determinants of total body dose, that over-lead dose is high enough to warrant additional lead shielding for the head and neck, and that a double-thickness apron lowers under-lead dose by two-thirds. The large difference between under-lead and over-lead doses suggests that use of a collar badge alone for monitoring purposes is not predictive of total-body effective dose for this group of radiation workers.     

Evaluation of additional lead shielding in protecting the physician from radiation during cardiac interventional procedures

Since cardiac interventional procedures deliver high doses of radiation to the physician, radiation protection for the physician in cardiac catheterization laboratories is very important. One of the most important means of protecting the physician from scatter radiation is to use additional lead shielding devices, such as tableside lead drapes and ceiling-mounted lead acrylic protection. During cardiac interventional procedures (cardiac IVR), however, it is not clear how much lead shielding reduces the physician dose. This study compared the physician dose [effective dose equivalent (EDE) and dose equivalent (DE)] with and without additional shielding during cardiac IVR. Fluoroscopy scatter radiation was measured using a human phantom, with an ionization chamber survey meter, with and without additional shielding. With the additional shielding, fluoroscopy scatter radiation measured with the human phantom was reduced by up to 98%, as compared with that without. The mean EDE (whole body, mean+/-SD) dose to the operator, determined using a Luxel badge, was 2.55+/-1.65 and 4.65+/-1.21 mSv/year with and without the additional shielding, respectively (p=0.086). Similarly, the mean DE (lens of the eye) to the operator was 15.0+/-9.3 and 25.73+/-5.28 mSv/year, respectively (p=0.092). In conclusion, although tableside drapes and lead acrylic shields suspended from the ceiling provided extra protection to the physician during cardiac IVR, the reduction in the estimated physician dose (EDE and DE) during cardiac catheterization with additional shielding was lower than we expected. Therefore, there is a need to develop more ergonomically useful protection devices for cardiac IVR.     

Estimation of operator dose by dose area product meter

Because of the more advanced and more complex procedures in interventional radiology (IVR), longer treatment times have become necessary. Therefore, it is important to determine the exposure doses received by operators and patients. Operator doses arising from the use of X-rays are mainly due to scattered radiation. The purpose of this study was to assess the feasibility of estimating operator dose by dose area product (DAP), which shows the total X-ray output from the collimator. DAP showed a strong correlation with the space dose from the fundamental examination. In clinical practice, we measured the exposure doses of the neck, left shoulder, left hand, and right finger using a thermoluminescence dosimeter (TLD). These then were compared with the DAP. The results indicated that the dose equivalents (H70 microm) of the neck and left shoulder were strongly correlated with DAP (r=0.85, 0.86), whereas the H70 microm of the left hand and right finger were less closely correlated (r=0.40, 0.48). In comparison with the fluoroscopic time, the dose equivalents showed a better correlation with DAP in all the evaluated parts. The effective doses for the operator were strongly correlated with DAP (r=0.87). When measurements are not available, dose equivalents and operator effective doses can be estimated by the DAP, as indicated by the strong correlations recognized in this study.     

Occupational radiation doses in interventional cardiology: a 15-year follow-up

This report describes occupational radiation doses of interventional cardiologists over 15 years and assesses action undertaken to optimize radiation protection. Personal dosimetry records of nine staff cardiologists and eight interventional cardiology fellows were recorded using personal dosemeters worn over and under their lead aprons. The hospital in which this study was conducted currently performs 5000 cardiology procedures per year. The hospital has improved its facilities since 1989, when it had two old-fashioned theatres, to include four rooms with more advanced and safer equipment. Intensive radiation protection training was also implemented since 1989. Initially, some individual dose values in the range of 100-300 mSv month(-1), which risked exceeding some regulatory dose limits, were measured over the lead apron. Several doses in the range of 5-11 mSv month(-1) were recorded under the apron (mean = 10.2 mSv year(-1)). During the last 5 years of the study, after the implementation of the radiation protection actions and a programme of patient-dose optimization, the mean dose under the apron was reduced to 1.2 mSv year(-1). Current mean occupational doses recorded under the lead apron are 14% of those recorded during 1989-1992 and those recorded over the apron are 14-fold less than those recorded during 1989-1992. The regulatory dose limits and the threshold for lens injuries might have been exceeded if radiation protection facilities had not been used systematically. The most effective actions involved in reducing the radiation risk were training in radiation protection, a programme of patient-dose reduction and the systematic use of radiation protection facilities, specifically ceiling-suspended protective screens.     

3种介入术中工作人员的辐射剂量水平分析

目的 分析和评价临床实施较多的3种典型介入术中,工作人员的辐射剂量水平.方法 用仿真模体模拟实际诊疗情况,用热释光(TLD)元件作为测量工具,检测X射线机旁有/无防护组合时介人工作者眼晶状体、颈部及胸部的辐射剂量水平,估算其眼晶状体当量剂量和有效剂量.结果 X射线机旁有防护设施条件下,头部受照剂量减少85%～90%.脑血管介入术第一手术者眼晶状体当量剂量高于心血管和外周血管介入术,外周血管介入术第一手术者年有效剂量低于脑血管和心血管介入术.结论 介入工作者在本研究中使用的防护措施及适当的工作强度下,年有效剂量不会超过20 mSv的限值,但眼晶状体当量剂量可能会超过ICRP最新推荐的眼晶状体剂量限值(20 mSv),介入工作者应重视对眼晶状体的防护.

Abstract：

Objective To assess the level of radiation exposures of operators in three typical types of interventional fluoroscopic procedures.Methods Alderson Radiation Therapy (ART) phantom was used to stimulate the practices of diagnosis and therapy using TLDs for dose measurement.The radiation exposures of eye lens, neck, and breast were measured when the lead shielding of machine was on/off and the equivalent dose and effective dose to the eye lens were estimated.Results Radiation exposure of head was obviously reduced by 85% -90% when the lead shielding was on.The doses in different procedures were different.In cerebral angiography the dose equivalent of eye len was the highest in the three procedures.The annual effective dose for the operators was smaller in peripheral vascular interventions than that in cardiovascular interventional therapy and that in cerebral angiography.Conclusions The operators involved in intervention will receive an annual effective dose of less than 20 mSv as recommended by the ICRP under the protection conditions provided by the current study, except for eye lens.Attention should be paid to the protection of the eyes of operators.     

Radiation exposure in endovascular surgery of the head and neck.

PURPOSETo evaluate the radiation risk to the operator and the patient during endovascular surgery of the head and neck.METHODSThe dose was measured using thermoluminescence dosimeters attached at the body surface of the operator and the patient during 15 endovascular surgeries (3 for arteriovenous malformation, 8 for dural arteriovenous fistulas, and 4 for other disorders of the head and neck). The dose was measured at seven sites on the operator and at five sites on the patient.RESULTSThe mean number of digital subtraction angiography studies and fluoroscopy time were 21 +/- 10 and 73 +/- 24 minutes, respectively. The equivalent dose range at each site in the operator was 0.12 to 0.88 mSv (glabella), 0.06 to 1.1 and 0 to 0.09 mSv (neck, outside and inside the protector, respectively), 0 to 0.20 mSv (left should, inside the protector), 0.09 to 1.99 mSv (left arm), 0.05 to 3.55 mSv (left hand), and 0 to 0.49 mSv (pubis, inside the protector). Those in the patients were 3.1 to 136 mSv (glabella), 13 to 5441 mSv (right temporal area), 4 to 186 mSv (left temporal area), 0.1 to 51 mSv (neck), and 0 to 0.62 mSv (pubis).CONCLUSIONSThe total doses at the operator''s eyes and left hand during the course of a year may exceed the dose limits recommended by the International Commission on Radiological Protection. Operators should wear not only body protectors, but also thyroid protectors and lead glass spectacles. The equivalent dose at the right temporal area of the patient may exceed the deterministic dose for transient erythema or alopecia of the skin even in one endovascular procedure.     

Personnel exposure in intraoperative biliary radiology

The diffusion of percutaneous procedures under fluoroscopic guidance has raised the question of excessive radiation exposure to the patient and to the interventional radiology personnel. In order to give an answer to this question we prospectively evaluated the radiation doses received by the operator's hands, lens, thyroid, and gonads during 243 percutaneous cholangiographies and transhepatic biliary drainages. The absorbed dose was measured with calibrated lithium fluoride thermoluminescent dosimeters applied to the skin (hands, neck, forehead, and gonads). The range of absorbed doses to the four areas was: from 0.013 to 0.219 mGy for the hands, from 0.011 to 0.027 mGy for the thyroid, from 0.007 to 0.019 mGy for the lens; the gonads dose was not measurable due to the dosimeter being placed behind the lead apron. The radiation dose employed during our biliary interventional procedures is higher than that of selective visceral angiography, but lower than that of PTA. On the basis of our data, a radiologist could perform about 2777 PTCs, or 1718 percutaneous biliary drainages, per annum, without exceeding the ICRP dose limits.     

Staff Radiation Doses to the Lower Extremities in Interventional Radiology

The purpose of this study was to investigate the radiation doses to the lower extremities in interventional radiology suites and evaluate the benefit of installation of protective lead shielding. After an alarmingly increased dose to the lower extremity in a preliminary study, nine interventional radiologists wore thermoluminescent dosimeters (TLDs) just above the ankle, over a 4-week period. Two different interventional suites were used with Siemens undercouch fluoroscopy systems. A range of procedures was carried out including angiography, embolization, venous access, drainages, and biopsies. A second identical 4-week study was then performed after the installation of a 0.25-mm lead curtain on the working side of each interventional table. Equivalent doses for all nine radiologists were calculated. One radiologist exceeded the monthly dose limit for a Category B worker (12.5 mSv) for both lower extremities before lead shield placement but not afterward. The averages of both lower extremities showed a statistically significant dose reduction of 64% (p < 0.004) after shield placement. The left lower extremity received a higher dose than the right, 6.49 vs. 4.57 mSv, an increase by a factor of 1.42. Interventional radiology is here to stay but the benefits of interventional radiology should never distract us from the important issue of radiation protection. All possible measures should be taken to optimize working conditions for staff. This study showed a significant lower limb extremity dose reduction with the use of a protective lead curtain. This curtain should be used routinely on all C-arm interventional radiologic equipment.     

Patient radiation doses and references levels in interventional radiology

PURPOSE: To set Diagnostic Reference Levels (DRLs) in interventional radiology by means of dose area product (DAP) measurements and the grouping of homogeneous procedures, and to quantify the associated errors in the DRL estimates. To evaluate the Mean Effective Doses per single procedure. MATERIALS AND METHODS: Interventional radiology procedures were divided into four main groups: neuroradiological, vascular, extravascular and paediatric. Neuroradiological and vascular procedures were further divided into diagnostic and interventional procedures. Starting from DAP and total fluoroscopy time measurements in 1,256 patients, the DRLs were determined for 17 procedures, together with an estimate of their uncertainty. The correlation between fluoroscopy time and DAP was assessed. Mean effective dose estimates were obtained from measured DAP values and from the analysis of the dosimetric data reported in the literature for similar procedures. RESULTS: The main features of DAP distributions are long high-dose tails, indicating asymmetric distributions, together with a large interquartile range. Rounded third-quartile values of DAP distributions showed a large range in the procedures taken into consideration. Values of 147, 198, 338 Gy cm(2)were obtained for supra-aortic angiography, cerebral angiography and embolization. Values of 86-101 and 459-438 Gy cm(2)were obtained for diagnostic and interventional vascular procedures on the lower limbs and on the abdomen, respectively. Values of 25-33 Gy cm(2)were obtained for retrograde cystourethrographies and ERCP, and values of 62-158 Gy cm(2)were obtained for nephrostomy and percutaneous transhepatic cholangiography. The correlation between total fluoroscopy time and the DAP values was poor. Mean effective dose estimates showed lower values for extravascular procedures (4.8-28.2 mSv), intermediate values for neuroradiological procedures (12.6-32.9 mSv) and higher values for vascular procedures involving the abdomen (36.5-86.8 mSv). DISCUSSION: DAP values were generally higher in vascular than in extravascular procedures. In generally, interventional vascular procedures show higher DAP values than the corresponding diagnostic procedures, with the exception of the abdominal region where the values were similar. Extravascular procedures with percutaneous access show significantly higher DAP values than those with endoscopic access. Total fluoroscopy time is a poor predictor of patient doses in interventional radiology. CONCLUSIONS: The systematic recording of DAP values, together with adequate grouping of similar procedures makes it possible to establish stable DRLs on a local basis and to carry out dosimetric evaluations, although on a statistical rather than individual basis. Patient radiation doses during interventional radiological procedures may be high, particularly when the abdominal region is involved.     

Evaluation of the Occupational Doses of Interventional Radiologists

The aim of the present study was to determine whether there is a linear relation between the doses measured above and those measured under the lead apron of the radiologists performing interventional procedures. To monitor radiation exposure the International Commission of Radiological Protection (ICRP) recommends the use of a single dosimeter under the protective apron. To determine the exposure more accurately an additional dosimeter is recommended above the protective apron. The exposure of eight radiologists was monitored with two personal dosimeters during 3 consecutive years. To measure the doses uniformly the two dosimeters were worn in a special holder attached to the lead apron. The two personal dosimeters were replaced every 4 weeks on the same day. The doses above and under the protective aprons of seven radiologists did not differ significantly. A significant lower dose above and under the protective apron was measured for one of the radiologists. During a 4-week period the average dose measured above the lead apron was 3.44 mSv (median, 3.05 mSv), while that under the 0.25-mm lead apron was 0.12 mSv (median, 0.1 mSv). The coefficients of the regression line result in the equation Y = 0.036X − 0.004, with Y as the dose under the lead apron and X as the dose above the lead apron. The statistical analysis of the data established a linear relation between the doses above and those under the lead apron (R ² = 0.59). Before the special holder was introduced it was not possible to derive a relation between the doses above and those under the lead apron, as the doses were measured at varying places above and under the lead apron. There is no evidence that the effective dose can be estimated more accurately when an additional dosimeter is used. The present study revealed a threshold before doses under the lead apron were measured. Due to the threshold it can be concluded that the doses under the lead apron will not be underestimated easily when doses above the lead apron are used to calculate them. This is not the case when the doses above the lead apron are calculated for the doses under the lead apron.     

Radiation exposure to cardiologists performing interventional cardiology procedures

Medical doctors, who practice interventional cardiology, receive a noticeable radiation dose. In this study, we measured the radiation dose to 9 cardiologists during 144 procedures (72 coronary angiographies and 70 percutaneus translumined coronary angioplasties) in two Greek hospitals. Absorbed doses were measured with TLD placed underneath and over the lead apron at the thyroid protective collar. Based on these measurements, the effective dose was calculated using the Niklason method. In addition, dose area product (DAP) was registered. The effective doses, E, were normalised to the total DAP measured in each procedure, producing the E/DAP index. The mean effective dose values were found to be in the range of 1.2-2.7 microSv while the mean E/DAP values are in the range of 0.010-0.035 microSv/Gycm2. The dependence of dose to the X-ray equipment, the exposure parameters and the technique of the cardiologist were examined. Taking under consideration the laboratories' annual workload, the maximum annual dose was estimated to be 1.9 and 2.8 mSv in the two hospitals.     

三种双剂量计法估算介入术者有效剂量比较

目的 比较3种双剂量计算法估算介入术者有效剂量的优劣。方法 在仿真人体模内布放热释光剂量片并将体模置于介入术者位置,在体模外穿戴铅防护衣、铅围脖和铅帽,并在铅衣内左前胸和铅围脖外左侧放置个人剂量计,在手术台上放置散射模体,分别为CIRS放疗调强体模和CT剂量检测模体,模拟介入手术曝光条件曝光一定时间,通过器官组织吸收剂量估算有效剂量;以3种双剂量计法计算有效剂量并与体模法结果进行比较。结果 得到两组各4个有效剂量结果,即使用CIRS放疗调强体模时,体模法、NCRP法、Niklason法和Boetticher法分别为0.138、0.097、0.161和0.173 mSv;使用CT剂量检测模体时分别为0.018、0.013、0.019和0.026 mSv。其中,Niklason法与体模法最为接近。结论 对于估算介入术者的有效剂量,Niklason法更为准确和实用。     

2014-2018年江西省医用放射工作人员外照射个人剂量监测结果分析

目的分析江西省医疗机构放射工作人员的外照射个人剂量情况,为放射防护工作提供参考。方法以2014—2018年江西省医疗机构不同工种放射工作人员为调查对象,工种包括诊断放射学、放射治疗、核医学和介入放射学,统计分析江西医用放射工作人员的受照剂量水平。结果本次共调查23833人次,平均人均年有效剂量为0.316 mSv,受监测人员中年有效剂量超过1 mSv的工作人员数与受监测人员总数的比值(NR1)为4.32%,年有效剂量超过5 mSv的工作人员数与受监测人员总数的比值(NR5)为0.10%。2014—2018年间,人均年有效剂量呈现先上升后回落的趋势,2017年达到峰值。5年间监测从事诊断放射学人员有17909人次,占总监测人次的75.14%;人均年有效剂量最高的工种是介入放射学,为0.329 mSv,其他工种由大到小排列依次为诊断放射学、核医学和放射治疗,分别为0.318、0.283和0.269 mSv,不同工种放射工作人员比较,差异有统计学意义(χ2=489.39,P<0.001)。结论江西医疗机构放射工作人员人均年有效剂量符合国家标准要求,核医学受照剂量水平总体呈现出上升趋势,一、二级医院放射工作人员的受照剂量水平较高,建议加强核医学及一、二级医院放射工作人员的监管力度。     

湖北省2009-2018年放射工作人员职业性外照射剂量监测结果分析

目的回顾性分析湖北省2009—2018年间放射工作人员职业性外照射个人剂量水平与分布情况,预防和控制放射性职业照射的风险。方法以2009—2018年委托湖北省疾病预防控制中心进行个人剂量监测的放射工作人员外照射个人剂量为研究对象,共50070人。按照相关国家标准的要求,采用热释光方法监测放射工作人员的外照射剂量当量。结果10年间放射工作人员平均年集体有效剂量为1.93人·Sv,人均年有效剂量中位数为0.14 mSv(P25~P75为0.06~0.30 mSv),人均年有效剂量为0.40 mSv;年有效剂量<1 mSv的有46562人,占总监测人群的92.99%。不同职业类别的年有效剂量变化趋势不尽相同,但总体趋势均呈逐年下降的态势,并于2012年之后维持在较低水平。医学应用中核医学和介入放射学、工业应用中探伤和测井以及其他类放射工作人员人均年有效剂量相对较高。结论人均年有效剂量呈逐年降低并维持较低水平的趋势,表明10年间的放射防护措施基本能够保障其健康权益。连续性的监测结果提示,需对职业类别如核医学、介入放射学、探伤和测井以及其他类应用的放射工作人员予以重点关注,保障放射防护措施。     

心血管病介入诊疗程序中第一术者有效剂量估算方法的比较研究

目的 通过模拟实验测量,比较国际辐射防护委员会（ICRP）139号报告推荐的4种单双剂量计算法对估算心血管介入诊疗程序中第一术者有效剂量之间的差异,以探讨这4种算法对介入诊疗场景的适用性。方法 模拟第一术者的男性躯干模体穿戴铅衣和铅围脖,在其体内布放热释光探测器,在其铅衣内外布放热释光个人剂量计,模拟心血管病介入诊疗场景,通过模拟测量得到的器官剂量计算第一术者的有效剂量,与通过个人剂量计及4种单双剂量计算法得到的结果进行比较。结果 在本实验条件下,由模拟测量计算得到的有效剂量为0.581 mSv;而用Swiss ordinance法、McEwan法、Von Boetticher法与Martin-Magee法估算得到的有效剂量分别为0.667、0.484、0.485和0.726 mSv,与模拟测量得到的有效剂量的相对偏差分别为14.8%、-16.7%、-16.5%和24.9%。结论 4种计算方法得到第一术者有效剂量与模拟测量结果均有较大的差异;从辐射防护观点出发,推荐使用Swiss ordinance法开展心血管病介入诊疗程序中第一术者的个人剂量监测。     

Evaluation of the effectiveness of X-ray protective aprons in experimental and practical fields

Few practical evaluation studies have been conducted on X-ray protective aprons in workplaces. We examined the effects of exchanging the protective apron type with regard to exposure reduction in experimental and practical fields, and discuss the effectiveness of X-ray protective aprons. Experimental field evaluations were performed by the measurement of the X-ray transmission rates of protective aprons. Practical field evaluations were performed by the estimation of the differences in the transit doses before and after the apron exchange. A 0.50-mm lead-equivalent-thick non-lead apron had the lowest transmission rate among the 7 protective aprons, but weighed 10.9 kg and was too heavy. The 0.25 and 0.35-mm lead-equivalent-thick non-lead aprons differed little in the practical field of interventional radiology. The 0.35-mm lead apron had lower X-ray transmission rates and transit doses than the 0.25-mm lead-equivalent-thick non-lead apron, and each of these differences exceeded 8 % in the experimental field and approximately 0.15 mSv/month in the practical field of computed tomography (p < 0.01). Therefore, we concluded that the 0.25-mm lead-equivalent-thick aprons and 0.35-mm lead apron are effective for interventional radiology operators and computed tomography nurses, respectively.     

Estimation of the effective dose of patient in interventional radiology: study of coronary angiography

The applications of interventional radiology (IVR) increasingly are being used in clinical examinations, where they tend to extend examination time. In addition, the risk of occupational exposure necessarily is increasing with this technology. In this study, the dose distributions in a sliced acrylic-acid phantom involving the bore for each irradiation condition were measured using a thermoluminescence dosimeter (TLD). Four patterns of set-up for the fluoroscopy unit were chosen as references for the conditions generally used clinically. Exposure also was measured with dose area product (DAP), and we then calculated the entrance skin dose and effective dose for the patient. The results showed that the effective dose was 7.0 mSv to 8.0 mSv at LAO45 degrees and RAO30 degrees; 100 kV, 2.3 mSv to 3.3 mSv at LAO45 degrees and RAO30 degrees; 80 kV. The effective dose is greatly influenced by the setup of fluoroscopy in IVR. The change in DAP is especially influenced. We found that the relation between DAP and effective dose was corrected with the exponential function. The effective doses were not necessarily less than those of other radiation examinations, and increase. When PCI and TAE are repeated many times in IVR, we propose that the effective dose should be taken into consideration together with the skin dose for dose control management.     

Radiation Dose of Nurses during IR Procedures: A Controlled Trial Evaluating Operator Alerts before Nursing Tasks

PurposeTo compare radiation exposure of nurses when performing nursing tasks associated with interventional procedures depending on whether or not the nurses called out to the operator before approaching the patient.Materials and MethodsIn a prospective study, 93 interventional radiology procedures were randomly divided into a call group and a no-call group; there were 50 procedures in the call group and 43 procedures in the no-call group. Two monitoring badges were used to calculate effective dose of nurses. In the call group, the nurse first told the operator she was going to approach the patient each time she was about to do so. In the no-call group, the nurse did not say anything to the operator when she was about to approach the patient.ResultsIn all the nursing tasks, the equivalent dose at the umbilical level inside the lead apron was below the detectable limit. The equivalent dose at the sternal level outside the lead apron was 0.16 μSv ± 0.41 per procedure in the call group and 0.51 μSv ± 1.17 per procedure in the no-call group. The effective dose was 0.018 μSv ± 0.04 per procedure in the call group and 0.056 μSv ± 0.129 per procedure in the no-call group. The call group had a significantly lower radiation dose (P = .034).ConclusionsRadiation doses of nurses were lower in the group in which the nurse called to the operator before she approached the patient.     

PET/CT-guided Interventions: Personnel Radiation Dose

Purpose

To quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.

Methods

In this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).

Results

The median effective dose was 0.02 (range 0–0.13) mSv for the primary operator, 0.01 (range 0–0.05) mSv for the nurse anesthetist, and 0.02 (range 0–0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0–0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).

Conclusion

The operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.     

Radiation risks for the radiologist performing transjugular intrahepatic portosystemic shunt (TIPS)

The aim of this study is to evaluate the radiation dose to the interventional radiologist in transjugular intrahepatic portosystemic shunt (TIPS) concerning the risk of cancer and deterministic radiation effects and the relation to recommended dose limits. In 18 TIPS interventions radiation doses were measured with thermoluminescence dosemeters (TLD) fixed at the eyebrow, thyroid and hand of the radiologist without special lead shielding of these body parts and at the chest, abdomen and testes under the lead apron. The doses of the eye lens, thyroid gland and hand were assumed to be equal to the corresponding surface doses. The dose at the abdomen under the lead apron was used as an estimation of the ovarian dose. Effective dose equivalent was estimated by Webster's method. The estimated effective dose equivalent was 0.087 mSv and the effective dose 0.110 mSv. The risk of fatal cancer was of 10(-6) and the risk of severe genetic defect of 10(-7) for one single intervention. The maximum permissible number of TIPS interventions was 181, otherwise the dose limit for effective dose would be exceeded. When the radiologist performed more than 372 TIPS procedures per year for many years, the dose to the lens of the eye could exceed the threshold for cataract. If the interventionist performs a large number of TIPS procedures in a year, the risk of fatal cancer and developing cataracts becomes relatively high.