Abstract
Background:
The present study aimed to evaluate the degree of radiation shielding effects according to lead equivalent thickness and distance during C-arm fluoroscopy-guided lumbar interventions.
Methods:
The exposure time and air kerma were recorded using a fluoroscope. The effective dose (ED) was measured with and without the shielding material of the lead apron using 2 dosimeters at 2 positions. According to the lead equivalent thickness of the shielding material and distance from the side of the table, the groups were divided into 4 groups: group 1 (lead equivalent thickness 0.6 mm, distance 0 cm), group 2 (lead equivalent thickness 0.6 mm, distance 5 cm), group 3 (lead equivalent thickness 0.3 mm, distance 0 cm), and group 4 (lead equivalent thickness 0.3 mm, distance 5 cm). Mean differences such as air kerma, exposure time, ED, and ratio of EDs (ED with protector/ED without protector) were analyzed.
Results:
A total of 400 cases (100 cases in each group) were collected. The ratio of ED was significantly lower in groups 1 and 2 (9.18 ± 2.78% and 9.56 ± 3.29%, respectively) when compared to that of groups 3 and 4 (21.93 ± 4.19% and 21.53 ± 4.30%, respectively). The reductive effect of a 5-cm distance was 33.3% to 36.1% when comparing the ED between groups 1 and 2 and groups 3 and 4.
Conclusions:
The 0.3- and 0.6-mm lead equivalent thickness protectors have a radiation attenuation effect of 78.1% to 78.5% and 90.4% to 90.8%, respectively. The 5-cm distance from the side of the table reduces radiation exposure by 33.3% to 36.1%.
Keywords: air kerma, distance, fluoroscopy, lead equivalent thickness, physicians, radiation, radiation exposure, radiation shielding
1. Introduction
C-arm fluoroscopy-guided interventions are widely used by pain physicians nowadays.[1] It can visualize the bone and joint, thereby enhancing the accuracy of the intervention.[2] C-arm fluoroscopy is a device that uses X-rays. Therefore, repeated exposure to radiation can induce several radiation-induced diseases, such as cataract, radiation dermatitis, and various cancers, including brain cancer, breast cancer, and skin malignancies.[3–7] Cases of radiation-related complications in medical staff have also been reported.[8] Therefore, proper shielding and efforts to reduce radiation exposure are important for pain physicians.[9–11]
The 3 main components that determine a physician’s dose of radiation exposure are exposure time, distance from the radiation field, and shielding equipment.[12–17] The total exposure time related to fluoroscopic time per procedure can be reduced by enhanced personal proficiency gained through experience.[17] The position and location of each part of the body (e.g., chest, eye) during the procedure also affect the radiation exposure dose.[14] Radiation decreases according to the square of the distance from the radiation source, which is known as the “inverse square law.”[18,19] Shield devices such as lead aprons, thyroid protectors, lead gloves, and lead glasses can reduce radiation exposure.[20,21]
The aforementioned 3 components can be modified by individual pain physicians. A higher lead equivalent thickness for radiation protection aprons can reduce radiation exposure; however, thicker aprons may be more inconvenient due to their heavier weight compared to thinner aprons. The radiation transmission percentage according to lead thickness had been previously studied,[22] and the higher protection efficacy of thicker protectors is currently well known.[23] When producing a protector, the shape and thickness may be determined by considering the characteristics of the event in which the shield will be used and the material of the protector to be used. The shielding ability of each protector may be calculated using the linear and mass attenuation coefficients, half-value layer (HVL), or tenth-value layer (TVL) to determine theoretical values. In addition, when calculating the shielding ability to block radiation from an X-ray generator, both the primary line, which is the radiation intended to be used directly, and the secondary line caused by the scattering and leakage unrelated to use, must be considered. Therefore, the actual radiation protection efficacy may differ from the theoretical value due to scatter radiation and the position of each pain physician.[9,14,17] This can be confirmed with a setup that compares the radiation exposure inside and outside the lead apron using a dosimeter that measures the physician’s radiation exposure. However, direct comparison of radiation exposure according to the lead equivalent thickness during real C-arm fluoroscopy-guided interventions has been seldom studied. While the “inverse square law” is well-known, there is little study on the correlation between the distance from the table and radiation exposure. Therefore, in C-arm fluoroscopy-guided pain interventions, comparing the radiation exposure according to lead equivalent thickness and distance from the table can measure actual radiation exposure and raise awareness on the importance of using proper shielding devices and physicians’ positioning.
In this study, we aimed to compare the actual radiation exposure according to different lead equivalent thickness and distance from the table.
2. Methods
2.1. Patients and data collection
This study was approved by the Institutional Review Board of the Konkuk University Medical Center (IRB number: KUH1160097). After obtaining written informed consent, patients who visited the pain clinic of Konkuk University Medical Center from August 2019 to December 2019 for C-arm fluoroscopy-guided lumbar interventions, such as epidural block, medial branch block, and facet joint block, were enrolled. The baseline demographics of the enrolled patients were collected. Exclusion criteria were as follows: lack of informed consent, patients less than 20 years of age, coagulopathy, pregnancy, with history of lumbar spine surgery, or with history of allergic reaction to injected drugs for intervention. Two dosimeters were used with and without radiation protective material from the lead apron and recorded for effective dose (ED) during C-arm fluoroscopy-guided lumbar intervention. The lead equivalent thickness and distance from the radiation field (procedure table) were divided into 4 groups: group 1 (lead equivalent thickness 0.6 mm, distance from the table 0 cm), group 2 (lead equivalent thickness 0.6 mm, distance from the table 5 cm), group 3 (lead equivalent thickness 0.3 mm, distance from the table 0 cm), and group 4 (lead equivalent thickness 0.3 mm, distance from the table 5 cm).
2.2. Sample size justification
Currently, no similar study has been done. Based on prior research on the radiation shielding effect of the radiation-reducing glove,[16] it was decided that 100 participants in each group would be appropriate.
2.3. Randomization and masking
Using a concealed random number table, the groups (based on the lead equivalent thickness and distance) were randomly allocated. The random number table was made using Excel. It consisted of 100 participants for each group, with a total of 400 participants. A physician who did not perform the procedure set the dosimeters, protectors, and distances for each group. Another physician performed the procedure without knowledge on the lead equivalent thickness nor any information regarding the group.
2.4. Radiation detection
When the patients entered the procedure room and lied down on the procedure table, the C-shaped arm of the fluoroscopic device was moved to the side of the table. The irradiation device and image-receiving device were located above and below the procedure table. During the lumbar interventions, images were taken using the AP and lateral oblique views to confirm that the correct procedure using fluoroscopy. Radiation was emitted from the irradiation device past the patient in the field to an imaging device on the other side. During this time, in addition to the radiation directly emitted to the image confirmation device, radiation scattered to the surroundings was also generated. The air kerma indicating the radiation from the fluoroscopy and exposure time in each procedure were collected using a C-arm fluoroscope (OEC Elite; GE Healthcare, Salt Lake City, UT). The ED indicating the radiation exposure was measured using 2 dosimeters (PDM-227; Hitachi Aloka Medical, Ltd., Tokyo, Japan): one without the protector and the other with the protector (the radiation detector was covered with shielding material from the apron) (Fig. 1). The ratio of the ED (ED of the dosimeter with protector/ED of dosimeter without protector) was calculated for the protective effect in each group, which was considered as the primary outcome. The ratio of the ED related to the distance from the table was also calculated for the protective effect of the 5-cm distance, which was the secondary outcome. (Fig. 2).
Figure 1.
Schematic image of dosimeter location according to groups 1 to 4. (A) In group 1, the dosimeter with and without the protector (0.6 mm lead equivalent thickness) is placed right beside the C-arm fluoroscopy intervention table. (B) Dosimeters of group 2 are placed with and without the 0.6 mm lead equivalent protector and 5 cm away from the intervention table. (A) In group 3, the dosimeter setting is identical with group 1 except for the 0.3 mm lead equivalent thickness of the protector. (B) In group 4, the dosimeter with and without protector (0.3 mm lead equivalent thickness) is placed 5 cm away from the intervention table.
Figure 2.
The position of the 2 dosimeters at the side of the table. One dosimeter is wrapped with a 0.3 or 0.6 mm lead equivalent protector. Sensors are facing the patient and table.
2.5. Statistical analysis
All statistical analyses were performed using SPSS (version 17.0; IBM Corporation, Somers, NY). Analysis of variance (ANOVA) was used to compare continuous variables between the 4 independent groups. post hoc analysis with Tukey’s multiple comparison test was performed. Continuous variables were presented as mean ± standard deviation. Categorical variables were compared using the chi-square test. Statistical significance was set at P < .05.
3. Results
3.1. Baseline characteristics of enrolled patients
A total of 400 cases of C-arm fluoroscopy-guided lumbar intervention from August 2019 to December 2019, consisting of 100 cases in each group (groups 1–4), were included in the final analysis. There were no losses and exclusions after randomization. The mean age, sex distribution, height, and weight of each group were not significantly different (Table 1).
Table 1.
Comparison of baseline demographics of enrolled patients.
| Group 1 (0.6/0)* (N = 100) | Group 2 (0.6/5)* (N = 100) | Group 3 (0.3/0)* (N = 100) | Group 4 (0.3/5)* (N = 100) | P value | |
|---|---|---|---|---|---|
| Age (yr) | 59.97 ± 15.02 | 58.96 ± 17.46 | 56.97 ± 18.31 | 59.89 ± 17.91 | .579 |
| Female/Male | 43/ 57 | 51/49 | 48/ 52 | 40/60 | .400 |
| Height (cm) | 165.53 ± 8.38 | 163.38 ± 9.94 | 161.93 ± 9.71 | 163.37 ± 9.35 | .059 |
| Weight (kg) | 66.62 ± 9.11 | 66.39 ± 12.45 | 65.95 ± 11.42 | 66.36 ± 11.18 | .979 |
Data: mean ± standard deviation or number.
Lead equivalent thickness of protector (mm)/ Distance from side of table (cm).
3.2. Radiation exposure time, air kerma, and ED with/without protector from the lead apron
Detailed information on the radiation exposure is summarized in Table 2. The mean radiation exposure time and air kerma recorded in fluoroscopy were similar among the 4 groups (P = .403, P = .406, respectively).
Table 2.
Comparison of radiation exposure time and intensity between groups 1–4.
| Group 1 (N = 100) | Group 2 (N = 100) | Group 3 (N = 100) | Group 4 (N = 100) | P value | |
|---|---|---|---|---|---|
| Exposure time (s) | 19.58 ± 11.31 | 22.06 ± 12.47 | 20.37 ± 11.67 | 19.91 ± 8.76 | .403 |
| Air Kerma (mGy) | 6.64 ± 4.61 | 6.96 ± 5.07 | 6.33 ± 4.45 | 5.80 ± 5.69 | .406 |
| Effective dose without protector (μSv) | 38.23 ± 26.00a | 25.49 ± 21.44b | 35.08 ± 23.77a | 23.40 ± 14.46b | <.001 |
| Effective dose with protector (μSv) | 3.56 ± 2.68a | 2.36 ± 2.05a | 7.90 ± 6.07b | 5.05 ± 3.29c | <.001 |
| Ratio of Effective dose (%) | 9.18 ± 2.78a | 9.56 ± 3.29a | 21.93 ± 4.19b | 21.53 ± 4.30b | <.001 |
Data: mean ± standard deviation or number.
Ratio of effective dose: Effective dose with protector/effective dose without protector.
Small letter: The same letters indicate non-significant differences between groups based on the Bonferroni multiple comparison test.
The ED from the dosimeter without protector was not significantly different in groups 1 and 3 (38.23 ± 26.00 and 35.08 ± 23.77 μSv, respectively, P = .738) and groups 2 and 4 (25.49 ± 21.44 vs 23.40 ± 14.46 μSv, respectively, P = .906). The ED from the dosimeter without a protector in groups 1 and 3 was higher than that in groups 2 and 4 (1 vs 2, P < .001; 1 vs 4, P < .001; 3 vs 2, P = .011; 3 vs 4, respectively, P < .001).
The ED from the dosimeter with protector was not significantly different in groups 1 and 2 (3.56 ± 2.68 vs 2.36 ± 2.05 μSv, respectively, P = .123). The ED from the dosimeter with protector of group 4 was higher than that of group 1 and 2 (P = .032 and P < .001, respectively). The ED from the dosimeter with protector in group 3 was higher than that of groups 1, 2, and 4 (7.90 ± 6.07 vs 3.56 ± 2.68 μSv, 7.90 ± 6.07 vs 2.36 ± 2.05 μSv, 7.90 ± 6.07 vs 5.05 ± 3.29 μSv, respectively, P < .001).
Finally, the exposure ratio of a 0.6-mm lead equivalent thickness protector was not significantly different between groups 1 and 2 (9.18 ± 2.78 and 9.56 ± 3.29, respectively, P = .887). The exposure ratio of a 0.3-mm lead equivalent thickness protector was not significantly different between groups 3 and 4 (21.93 ± 4.19 and 21.53 ± 4.30, respectively, P = .866), while the exposure ratios of the 0.6-mm lead equivalent thickness protector (groups 1 and 2) were lower than that of the ratios of the 0.3-mm lead equivalent thickness (groups 3 and 4, P < .001).
3.3. Reduction of ED with and without lead apron by a 5-cm distance from the procedure table
The reductive effect of taking a distance of 5 cm from the table was evaluated by calculating the ratio of the ED between groups 1, 2, 3, and 4 (Table 3). The ratio of the ED without the protector, which was group 2 (lead equivalent thickness 0.6 mm, distance from the table 5 cm) per group 1 (lead equivalent thickness 0.6 mm, distance from the table 0 cm), and group 4 (lead equivalent thickness 0.3 mm, distance from the table 5 cm) per group 3 (lead equivalent thickness 0.3 mm, distance from the table 0 cm) were 0.667 and 0.667, respectively. In addition, the ratio of the ED with protector, which is group 2 per group 1, and group 4 per group 3 were 0.663 and 0.639, respectively. A distance of 5 cm from the table could reduce the ED by 33.3% to 36.1%.
Table 3.
Reduction of effective dose according 5 cm distance (ratio of effective dose between groups 1 and 2 and between groups 3 and 4).
| Group 2 (5 cm)/Group 1 (0 cm) ratio | Group 4 (5 cm)/Group 3 (0 cm) ratio | |
|---|---|---|
| Ratio of effective dose without protector | 0.667 | 0.667 |
| Ratio of effective dose with protector | 0.663 | 0.639 |
4. Discussion
In the present study, we compared the actual radiation exposure according to different lead equivalent thickness and distances from the table. The shielding effect of the lead apron of 0.6- and 0.3-mm thickness were 90.4% to 90.8% and 78.1% to 78.5%, respectively, and the actual radiation exposure by comparing the ED with the protector showed that the 0.6-mm lead equivalent thickness was 2.1- to 2.2-fold more effective than the 0.3-mm lead equivalent thickness. Even a small distance (5 cm) from the table can reduce the radiation exposure by 33.3% to 36.1%. This may be noted since this compared the actual amount of radiation exposure according to the lead equivalent thickness and distance from the table, emphasizing the importance of wearing radiation shielding devices of proper thickness and maintaining a short distance, such as 5 cm from the table, that would be beneficial in reducing radiation exposure during C-arm fluoroscopy-guided interventions.
Radiation exposure is inevitable when using C-arm fluoroscopy-guided interventions. A previous study showed that even hand position could affect total radiation exposure.[14] Radiation exposure also differed according to the location of the body part (e.g., forehead, thyroid), even in the same pain physician.[24] In addition, the amount of radiation reduction by a relatively short distance (5 cm) has not yet been evaluated. In the present study, the actual reductive effect at a distance of 5 cm from the table was 33.3% to 36.1%. In another study, a distance of 20 cm from the table could reduce scatter radiation by 73.3%.[16] Although some differences exist between previous studies[16] and the present study in terms of distance (20 cm and 5 cm) and the type of protector used (lead glove and apron), these still support that a short distance can effectively reduce radiation exposure without any protector. In addition, in a study comparing the difference in radiation exposure between fellows and professors performing C-arm fluoroscopy-guided interventions, there was no difference in C-arm usage time, irradiated radiation dose, and procedure time. However, only the distance from the X-ray generator differed by an average of 3.7 cm, showing that the radiation exposure decreased by 22% to 35% for each body part.[24] Considering the current results of the studies, even a short distance from a table or an X-ray generator can reduce radiation exposure. Moreover, staying farther from a radiation source does not necessarily cost more.
Radiation shielding devices, such as aprons, gloves, glasses, and thyroid protectors, are used to protect various parts of the body.[6,9,25,26] The radiation attenuation of these devices depends on the lead equivalent thickness. Although it is not entirely about scatter radiation, which is considered the main cause of radiation exposure to medical staff, one study showed that the mean attenuation of 90% and 97% of the primary X-ray beam was demonstrated by 0.25-mm and 0.5-mm aprons, respectively.[27] Another study reported that the mean attenuation of 0.25-mm and 0.5-mm lead equivalent aprons at 100 kVp were 83.2% and 95.1%, respectively.[28] During pain interventions, the actual reductive efficacy of lead aprons has not yet been evaluated. In the present study, we revealed that 0.3-mm and 0.6-mm lead equivalent thickness apron could reduce scatter radiation by 78.1% to 78.5% and 90.4% to 90.8%, respectively. Moreover, doubling lead equivalent thickness from 0.3 mm to 0.6 mm could reduce radiation exposure by 53.3% to 55%. These findings may emphasize the importance of using radiation shielding devices of appropriate thickness to reduce radiation exposure for pain physicians and could be used as part of radiation safety education in the near future.
The protective role of radiation shielding devices is definite and recommended for use during C-arm fluoroscopy-guided interventions.[11] Since many studies describe the dangers of radiation and the need for protection, doctors are now more aware of the potential dangers of radiation compared to the early days of medical use of radiation. However, many physicians outside of radiology practice fluoroscopy-guided procedures without the same level of radiation safety training typically required of radiologists.[29–31] The perception of the need to use proper radiation shielding devices is relatively low among pain physicians, and only 39% of fellowship training pain physicians in Korea received radiation safety education.[12] The higher lead equivalent thickness of the radiation protective apron and the distance from the table, 2 factors noted above, can be easily controlled by each pain physician. This fact can motivate and encourage pain physicians to make efforts to reduce radiation exposure by controlling these feasible ways.
Although the present study suggests a way for pain physicians to be less exposed to radiation, it has several limitations. First, the effects of distance were only evaluated at 5 cm from the radiation fields. Second, only 2 lead equivalent thicknesses (0.3 and 0.6 mm) were compared in the present study. Third, the ED was checked in a fixed position, which could not reflect the actual dynamic position of pain physicians during the C-arm fluoroscopy-guided intervention.
In conclusion, the use of a 0.3 and 0.6 mm lead equivalent thickness apron could reduce the radiation exposure by 78.1% to 78.5% and 90.4% to 90.8%, respectively. The 5 cm away from the side of the table reduces radiation exposure by 33.3% to 36.1%. In conclusion, wearing a thicker lead apron and maintaining even a short distance away from the table could effectively reduce radiation exposure.
Author contributions
Conceptualization: Jae Hun Kim.
Data curation: Hae Chang Jeong.
Investigation: Hae Chang Jeong, Jae Hun Kim.
Methodology: Jae Hun Kim.
Supervision: Jae Hun Kim.
Visualization: Cho Long Kim.
Writing – original draft: Cho Long Kim.
Writing – review & editing: Jae Hun Kim.
Abbreviation:
- ED
- effective dose
The authors have no conflicts of interest to disclose.
The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.
How to cite this article: Kim CL, Jeong HC, Kim JH. Radiation shielding effects of lead equivalent thickness of a radiation protective apron and distance during C-arm fluoroscopy-guided pain interventions: A randomized trial. Medicine 2023;102:48(e36447).
Contributor Information
Cho Long Kim, Email: painfree@kuh.ac.kr.
Hae Chang Jeong, Email: haechangj21@gmail.com.
References
- [1].Friedly J, Chan L, Deyo R. Increases in lumbosacral injections in the medicare population: 1994 to 2001. Spine. 2007;32:1754–60. [DOI] [PubMed] [Google Scholar]
- [2].Manchikanti L, Cash KA, Moss TL, et al. Radiation exposure to the physician in interventional pain management. Pain Physician. 2002;5:385–93. [PubMed] [Google Scholar]
- [3].DiCarlo AL, Bandremer AC, Hollingsworth BA, et al. Cutaneous radiation injuries: models, assessment and treatments. Radiat Res. 2020;194:315–44. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [4].Little MP, Kitahara CM, Cahoon EK, et al. Occupational radiation exposure and risk of cataract incidence in a cohort of US radiologic technologists. Eur J Epidemiol. 2018;33:1179–91. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [5].Stahl CM, Meisinger QC, Andre MP, et al. Radiation risk to the fluoroscopy operator and staff. AJR Am J Roentgenol. 2016;207:737–44. [DOI] [PubMed] [Google Scholar]
- [6].Rampersaud YR, Foley KT, Shen AC, et al. Radiation exposure to the spine surgeon during fluoroscopically assisted pedicle screw insertion. Spine (Phila Pa 1976). 2000;25:2637–45. [DOI] [PubMed] [Google Scholar]
- [7].Rajaraman P, Doody MM, Yu CL, et al. Cancer risks in US radiologic technologists working with fluoroscopically guided interventional procedures, 1994-2008. AJR Am J Roentgenol. 2016;206:1101–8; quiz 1109. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [8].Valentin J. Avoidance of radiation injuries from medical interventional procedures. Ann ICRP. 2000;30:7–67. [DOI] [PubMed] [Google Scholar]
- [9].Meisinger QC, Stahl CM, Andre MP, et al. Radiation protection for the fluoroscopy operator and staff. AJR Am J Roentgenol. 2016;207:745–54. [DOI] [PubMed] [Google Scholar]
- [10].Miller DL, Vañó E, Bartal G, et al.; Cardiovscular and Interventional Radiology Society of Europe. Occupational radiation protection in interventional radiology: a joint guideline of the Cardiovascular and Interventional Radiology Society of Europe and the Society of Interventional Radiology. Cardiovasc Intervent Radiol. 2010;33:230–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [11].Holmberg O, Czarwinski R, Mettler F. The importance and unique aspects of radiation protection in medicine. Eur J Radiol. 2010;76:6–10. [DOI] [PubMed] [Google Scholar]
- [12].Kim TH, Hong SW, Woo NS, et al. The radiation safety education and the pain physicians’ efforts to reduce radiation exposure. Korean J Pain. 2017;30:104–15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [13].Park PE, Park JM, Kang JE, et al. Radiation safety and education in the applicants of the final test for the expert of pain medicine. Korean J Pain. 2012;25:16–21. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [14].Jung CH, Ryu JS, Baek SW, et al. Radiation exposure of the hand and chest during C-arm fluoroscopy-guided procedures. Korean J Pain. 2013;26:51–6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [15].Chang YJ, Kim AN, Oh IS, et al. The radiation exposure of radiographer related to the location in C-arm fluoroscopy-guided pain interventions. Korean J Pain. 2014;27:162–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [16].Kim AN, Chang YJ, Cheon BK, et al. How effective are radiation reducing gloves in C-arm fluoroscopy-guided pain interventions? Korean J Pain. 2014;27:145–51. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [17].Park S, Kim M, Kim JH. Radiation safety for pain physicians: principles and recommendations. Korean J Pain. 2022;35:129–39. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [18].Shafiei SA, Hasanzadeh H, Shafiei SA. A simple calculation method for determination of equivalent square field. J Med Phys. 2012;37:107–11. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [19].Curry TS, Dowdey JE, Murry RC. Christensen’s Physics of Diagnostic Radiology. Philadelphia: Lippincott Williams & Wilkins; 1990. [Google Scholar]
- [20].Cheon BK, Kim CL, Kim KR, et al. Radiation safety: a focus on lead aprons and thyroid shields in interventional pain management. Korean J Pain. 2018;31:244–52. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [21].Magee JS, Martin CJ, Sandblom V, et al. Derivation and application of dose reduction factors for protective eyewear worn in interventional radiology and cardiology. J Radiol Prot. 2014;34:811–23. [DOI] [PubMed] [Google Scholar]
- [22].McCaffrey JP, Shen H, Downton B, et al. Radiation attenuation by lead and nonlead materials used in radiation shielding garments. Med Phys. 2007;34:530–7. [DOI] [PubMed] [Google Scholar]
- [23].Vano E, Gonzalez L, Fernandez JM, et al. Influence of patient thickness and operation modes on occupational and patient radiation doses in interventional cardiology. Radiat Prot Dosim. 2006;118:325–30. [DOI] [PubMed] [Google Scholar]
- [24].Choi EJ, Go G, Han WK, et al. Radiation exposure to the eyes and thyroid during C-arm fluoroscopy-guided cervical epidural injections is far below the safety limit. Korean J Pain. 2020;33:73–80. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [25].Thomas RP, Grau M, Eldergash O, et al. Will X-ray safety glasses become mandatory for radiological vascular interventions? Cardiovasc Intervent Radiol. 2018;41:1074–80. [DOI] [PubMed] [Google Scholar]
- [26].Mroz TE, Yamashita T, Davros WJ, et al. Radiation exposure to the surgeon and the patient during kyphoplasty. J Spinal Disord Tech. 2008;21:96–100. [DOI] [PubMed] [Google Scholar]
- [27].Livingstone RS, Varghese A. A simple quality control tool for assessing integrity of lead equivalent aprons. Indian J Radiol Imaging. 2018;28:258–62. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [28].Christodoulou EG, Goodsitt MM, Larson SC, et al. Evaluation of the transmitted exposure through lead equivalent aprons used in a radiology department, including the contribution from backscatter. Med Phys. 2003;30:1033–8. [DOI] [PubMed] [Google Scholar]
- [29].Bordoli SJ, Carsten CG, 3rd, Cull DL, et al. Radiation safety education in vascular surgery training. J Vasc Surg. 2014;59:860–4. [DOI] [PubMed] [Google Scholar]
- [30].Picano E, Vano E. The radiation issue in cardiology: the time for action is now. Cardiovasc Ultrasoun. 2011;9:Artn 35. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [31].Rehani MM, Ciraj-Bjelac O, Vano E, et al. ICRP publication 117 radiological protection in fluoroscopically guided procedures performed outside the imaging department. Ann ICRP. 2010;40:1–102. [DOI] [PubMed] [Google Scholar]