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Effect of Shields in Radiation Dose and Secondary Biological Risk of Gonads in Lumbosacral Digital and Computerized Radiography
Hamed Taheri1, Mohammad Bagher Tavakoli2, Nayyer Mostafavi3, Mojgan Esna Ashar2, Safura Mozafari4, Hossein Taheri2
1 Department of Nursing, Islamic Azad University of (Khorasgan), Isfahan, Iran
2 Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
3 Department of Radiation Oncology, Khansari Hospital, Arak University of Medical Sciences, Arak, Isfahan, Iran
4 Department of Emergency Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| Date of Submission | 27-Jun-2021 |
| Date of Acceptance | 31-Aug-2021 |
| Date of Web Publication | 31-Aug-2023 |
Correspondence Address:
Mohammad Bagher Tavakoli
Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan
Iran
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/abr.abr_187_21
Background: The purpose of this study was to evaluate the effect of shields in imposed radiation dose to gonads in anterior-posterior (AP) and lateral views of lumbosacral radiography using digital radiography (DR) and computerized radiography (CR) methods.
Materials and Methods: Sixty patients who were suspected to AP and lateral view of lumbosacral radiography were included in this study. The patients were exposed with and without shields which have 0.25 mm thickness. This study also compared the imposed dose to gonads for one and two plates of shields with none shields situation. Measurement of the radiation dose was performed using thermo luminescence dosimeters on the surface of the gonads. Furthermore, the absolute and excess relative risk (ERR) of biological abnormalities was estimated in the above-mentioned method using the BEIR VII model.
Results: The mean dose of the DR method (10.14 ± 0.27) for the AP view was significantly lower than CR (32.43 ± 0.17) with and without shields. In addition, the imposed dose to gonads in the lateral view of DR (6.41 ± 0.47) was lower compared to CR (9.38 ± 0.14). Furthermore, the mean imposed dose to gonads for one and two pate shields of DR was lower than CR. Moreover, the excess relative risk to gonads in the AP for DR was lower compared to CR in all mentioned situations.
Conclusion: Lumbosacral radiography is suggested to be performed by DR systems, due to the lower imposed dose and ERR to the gonads. Moreover, using shields may lead to decrease of scatter rays and also ERR of the gonads.
Keywords: Gonadal disorder, lumbosacral region, radiation dosimetry, risk assessment, thermoluminescent dosimetry
How to cite this article:
Taheri H, Tavakoli MB, Mostafavi N, Ashar ME, Mozafari S, Taheri H. Effect of Shields in Radiation Dose and Secondary Biological Risk of Gonads in Lumbosacral Digital and Computerized Radiography. Adv Biomed Res 2023;12:213 |
How to cite this URL:
Taheri H, Tavakoli MB, Mostafavi N, Ashar ME, Mozafari S, Taheri H. Effect of Shields in Radiation Dose and Secondary Biological Risk of Gonads in Lumbosacral Digital and Computerized Radiography. Adv Biomed Res [serial online] 2023 [cited 2023 Sep 26];12:213. Available from: https://www.advbiores.net/text.asp?2023/12/1/213/384830 |
| Introduction | |  |
Radiography is often the more suitable choice for diagnosing abnormalities of the human body, due to its simplicity, and also higher processing speed compared to other modalities such as computed tomography scan and magnetic resonance imaging. Computerized radiography (CR) and digital radiography (DR) modalities are commonly used in clinical situation[1] for the evaluation of the bone structures of the vertebrae and other parts of the human body. One of the more common clinical radiography techniques is the lumbosacral radiography, which is used for the assessment of bone structures and evaluation of the spinal cord. Furthermore, it is widely used to initial screening of suspected fractures of the vertebral bodies.[2],[3],[4] Lumbosacral radiography includes anterior-posterior (AP) and lateral view of them. Although this radiography has some advantages, it may lead to some adverse effects to critical organs such as gonads which are radiosensitive[5],[6] and also it can cause to some genetic mutations.[7] Some studies have been discussed about the gonadal dose in the radiographic techniques. Gyekye et al. have focused the radiation dose to some critical organs including the lung, heart, gall bladder, spleen, and gonads for lumbar spine radiography, using ionization chambers, and have found that about 10% of the genetic significant dose (GSD) is caused by diagnostic radiology.[5] Moreover, studies have shown that, high gonadal doses (over 500 mrad) which are from radiography of the lower abdomen and pelvis may lead to some genetic abnormalities.[7] Moreover, radiation exposure may lead to some chromosomal deformities.[5],[6],[7],[8],[9],[10]
Regarding to some literatures, using diagnostic X-rays may lead to some adverse effects to gonads,[9],[11],[12],[13],[14],[15] but to the best of our knowledge, there is a limited data about the impact of clinical lead shields on the gonadal dose and also the secondary biological risk of gonads in these modalities. Furthermore, radiographic systems have been provided X-ray with a wide range of energy spectrums. In addition, it would seem that the relation between gonadal dose and the risk of secondary biological effects (BEIR model) is unknown. Besides, it is considered that measuring the dose using TLD and surface skin dose may be reliable method to estimate the imposed biologic effects on gonads. Therefore, this study aimed to compare the imposed dose, and also relative risk (BEIR model) of gonads with/without shields in DR and CR systems.
| Materials and Methods | | |
Sixty patients who were suspected to AP and lateral view of lumbosacral radiography from November of 2020 to May 2021 were included in this study. The patients were exposed the radiography methods with and without shields which have 0.25 mm thickness. The AP and lateral views of lumbosacral radiography were done for the all patients [Figure 1]. The study was compared the effect of one and two plate of shields with none shields situation. Radiation measurement of the gonads was done using surface radiation dose.[4] The measurements were performed using LiF thermo luminescence dosimeters, LiF (TLD-100), which were placed on the gonad's skin of the patients. | Figure 1: Anterior-posterior (a) and lateral (b) of lumbosacral radiography of a 29-year-old male
Click here to view |
According to the patient's geometry and body thickness, the 65–75 kVp and 40 mAs was chosen on the Varian radiography machine for CR method. In addition, the 65–70 kVp and 40 mAs chosen on the Toshiba radiography machine for DR studies. The focal spot to film distance was chosen 100 cm for the all exposure. The TLDs were readout using SOLARO-2A TLD reader (NEC Technology).[16] Calibration of the TLDs were performed using 70 kVp x rays of Toshiba system and according with the manufacture procedure. Batch calibration of TLDs was done by dividing them to different groups. Dose measurements of gonads with and without shields were repeated for three independent experiments for calculating error measurements.
To calculate the radiation imposed adverse effects on the gonads, the BEIR model was used (equation 1).[12] The excess and absolute risk (ERR and EAR, respectively) of cancer was calculated according the following equation:
ERR = D βs exp (γe*) (α/60)η (1)
Where, D is radiation imposed dose; βS, γ, and η are organ-specific parameters for each sex; e is age at exposure; e* = (e − 30)/10 for e <30 and 0 for e >30 years; and a is the attained age.[17]
Statistical analysis
Mean (± standard deviation [SD]) of the radiation dose was calculated, and the statistical analysis of the differences among the values was evaluated using the SPSS (version 20, Chicago, IL, USA) computer software. Data were analyzed using Wilcoxon test as a nonparametric version of paired samples t-test. Criterion level of 0.05 was chosen for the statistical significant.
| Results | | |
[Table 1] shows the demographic characteristic table for our studied patients. The age range of them was 35.2 ± 8.5 and 41.3 ± 10.7 for CR and DR methods, respectively, and based on our data, the age range of them was not significant (P = 0.614). Besides, the lumbosacral thickness of the CR (12 ± 4) and DR patients (14 ± 2) was not significant (P = 0.826). Therefore, it is considered that the lumbosacral thickness variation was not affect the measured imposed dosed among patients. The employed kVp and mAs were selected according to manufacturer structures of the radiography systems. [Table 2] indicates the imposed radiation dose to gonads in AP view of DR and CR methods with and without shields. The mean (±SD) of gonadal dose was 32.43 ± 0.17 in AP view of CR, while it was 23.41 ± 0.14 and 18.79 ± 0.12 for one and two plate shields, respectively. The maximum and minimum imposed dose to them without shields was 34.12 and 27.52, respectively, for CR. Whereas for DR, the mean (±SD) of dose to gonads was 10.14 ± 0.27, but it was 6.38 ± 0.05 and 4.14 ± 0.09 for one and two shields, respectively. The maximum and minimum dose of them was 12.58 and 8.47 without shields. | Table 2: The imposed dose (rad) to gonads in the anterior-posterior view of lumbosacral radiography among the methods
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As shown in [Table 3], the mean (±SD) of gonadal dose was 9.38 ± 0.14 in the lateral view of CR; however, it was 5.74 ± 0.26 and 3.48 ± 0.12 for one and two plate shields, respectively. The maximum and minimum imposed dose of CR to them without shields was 12.24 and 7.85, respectively. The mean (±SD) of dose to gonads was 6.41 ± 0.47 for DR, but it was 2.39 ± 0.63 and 1.89 ± 0.08 for one and two shields, respectively. The maximum and minimum dose of them was 8.26 and 4.17 without shields. | Table 3: The imposed dose (rad) to gonads in the lateral view among the studied methods
Click here to view |
[Figure 2] and 34 illustrate the excess relative risk (ERR) of secondary biologic complications for gonads in AP and lateral views for none shield, one plate, and two plates among the DR and CR. The ERR for CR and DR method in AP view was 19 and 14, respectively (equation 1). In addition, it was found that the ERR of DR and CR with one plate lead shields was 10 and 12, respectively. The ERR for two plate shields of DR and CR in AP view was 4 and 6, respectively [Figure 3]. Whereas, for the lateral view, the ERR of secondary biologic complication for the DR and CR without shields was 11 and 15, respectively. Moreover, the ERR for the one plate shields for the DR and CR was 6 and 8, respectively. In this study, based on the equation 1, it was concluded that the ERR for two plate shields of DR and CR was 2 and 4, respectively [Figure 3]. Therefore, the relative secondary biological effects of lateral view were lower than AP view for the lumbosacral radiography. | Figure 2: The excess relative risk of gonads in the anterior-posterior view of lumbosacral radiography for computerized radiography (red lines) and digital radiography (blue lines)
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 | Figure 3: The excess relative risk of gonads in the lateral view of lumbosacral radiography for computerized radiography (red lines) and digital radiography (blue lines)
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| Discussion | | |
A number of studies have discussed about the effect of diagnostic radiography of the abdomen and pelvis on the GSD of population. Many literatures have been evaluated the imposed radiation dose to gonads as a radiosensitive organ which is located out of field of lumbosacral radiography, due to the impact of it on the genetic mutations and secondary abnormalities, but there is a limited evidence about the ERR to gonads among digital DR and CR with and without shields.
According our data, the mean dose to gonads was lower in AP view of DR compared to CR (up to 64%), which is an agreement with Priyanka et al. who found that the testicular dose of DR systems was 42% lower than CR.[4] It is also in line with the Conor et al. who stated that shields could lead to decrease the gonadal dose in the AP view of lumbosacral radiography.[10] In other study, Moilanen et al. have been reported that, the gonadal dose from lumbosacral radiography with shields was significantly lower compared to this without shields.[18]
Whereas, for the lateral method, the mean imposed dose to gonads of DR was lower (up to 46%) than CR modality. Similar results have been reported in other studies. Panicker et al. have been concluded that, the testicular dose of lateral view of DR was 42% lower in comparison with CR systems.[19] Priyanka et al. have been demonstrated that, the gonadal dose from lateral view of lumbosacral DR was 54% lower than CR.[4] Sinno-Tellier et al. have focused on the monthly probably pregnancy on males who underwent radiography and have reported that there was not any significant evidence about the detrimental effects of the ionizing beams on the monthly pregnancy probability,[20] but regarding to some literatures, the ionization beams may lead to some adverse effects on chromosomes.
Our data also showed that, as an expected, the ERR of gonads for none shields of DR was 28% lower than CR for AP view [Figure 1]. In addition, this value for DR was 33% and 30% lower than CR for one and two plate shields, respectively. Furthermore, the ERR of the none shield for lateral view of DR was 27% lower compared to CR. Moreover, the ERR of one and two plate shields of DR was 16% and 48% lower than CR for lateral view. These results are mostly depended to higher DQE of DR systems compared to CR,[1] which may lead to higher X-ray absorption of DR detectors. Although the higher kVp was used for lateral vies, the imposed radiation dose to gonads in this view was lower than AP view for the all discussed patients. Therefore, it would seem that, as an expected the AP irradiation of lumbosacral vertebrae may pose to more primary radiation incidence on the gonads compared to lateral views. Moreover, the lateral position of patients may lead to a sharp reduction of the scatter beams incidence on gonads.
Based on our findings, shields have significant impact on the gonadal dose, and also ERR reduction of gonads in AP and lateral views. It is largely due to decrease of out of field scatter beams followed by using shields. The amount of scatter rays is highly depended to beam energy (kVp), field size, and patient thickness.[1] Therefore, the mentioned parameters were chosen for each patients based on their geometry and body thickness. The smaller field size cause to better image quality, as a result of decrease of image noise and higher signal-to-noise ratio. Therefore, it was selected for different patients according to their body sizes.
It would seem that the greater dynamic range, higher efficiency of signal conversion, and also usage of higher kVp and the lower mAs in digital radiograph system may lead to lower patient exposure. Moreover, these findings are mainly due to using of AEC in DR of lumbosacral, while in CR system exposure factors are set by the radiographer.
Based on the result of this study, DR of lumbosacral not only may imposed lower radiation dose to gonads with and without shields compared to CR but also its relative risk to this stated radiosensitive organ may lower than other method, which may cause to lower genetic risks and chromosomal abnormalities.
| Conclusion | | |
In this study, the imposed radiation dose gonads and also ERR of cancer were compared lumbosacral radiography among DR and CR.
According to results of this work, lumbosacral radiography is proposed to be performed by DR systems, due to their lower dose and ERR to the critical out of field organs such as gonads compared to CR. Furthermore, using shields may lead to decrease the incidence of scatter rays to the stated organs.
Acknowledgment
The authors of this study would like to thanks the medical imaging center of Sayed-Al-Shohada hospital for their kind help for the completion of this work.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3]
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