|Year : 2021 | Volume
| Issue : 2 | Page : 191-195
Assessing liver functions of radiologic technologists exposed chronically to radiation
Sultan Zaher Alasmari1, Mohammed Makkawi1, Nasser Shubayr2, Gaffar Zaman1, Yazeed Alashban3, Nashwa Eisa1, Hussain Khairy4, Fuad Rudiny5, Basma Afif5
1 Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia
2 Department of Diagnostic Radiology, College of Applied Medical Sciences, Jazan University; Medical Research Center, Jazan University, Jazan, Saudi Arabia
3 Department of Radiological Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
4 Radiology Department, Sabia General Hospital, Ministry of Health, Saudi Arabia
5 Laboratory Department, Sabia General Hospital, Ministry of Health, Saudi Arabia
|Date of Submission||16-Apr-2021|
|Date of Acceptance||24-Apr-2021|
|Date of Web Publication||16-Jun-2021|
Sultan Zaher Alasmari
Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, King Khalid University, Abha
Source of Support: None, Conflict of Interest: None
Background: The continued absorption of occupational radiation encounter by radiologic technologists and the potential resulting adverse effects have been a concern to the field for decades. This study investigates the risk factors of developing liver dysfunction among a selected group of radiologic technologists (RTs) to evaluates the correlation between cumulative radiation doses and liver injury. Methods: Only RTs who have been working in the radiology department for more than 10 years were selected for the study. The RTs and control groups were chosen based on several factors: adults, nonalcoholic, non-smoker, and have no history of hypertension or diabetes. A retrospective analysis was performed on the effective cumulative radiation dose for a selected RTs from 2009 to 2019. Fully automated biochemical analyzer was used to evaluate liver function tests. Alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), total bilirubin (BiL), direct BiL, indirect BiL, albumin (ALB), total protein (TP), cholesterol (CHOL), triglyceride (TG), high-density lipoprotein (HDL), and glucose (GLUH) were measured. Results: The result showed that the difference in the medians of liver biomarker GGT between control and RTs groups was statistically significant. The median of GGT in RTs group was higher than that of the control group. Conclusions: GGT test is a hallmark of liver function and alteration in GGT level may indicate a hepatic defect. Thus, further investigation in a large cohort to study the association between GGT elevation and chronic radiation exposure is required.
Keywords: Cumulative radiation, liver function tests, liver injuries, radiologic technologists
|How to cite this article:|
Alasmari SZ, Makkawi M, Shubayr N, Zaman G, Alashban Y, Eisa N, Khairy H, Rudiny F, Afif B. Assessing liver functions of radiologic technologists exposed chronically to radiation. Biomed Biotechnol Res J 2021;5:191-5
|How to cite this URL:|
Alasmari SZ, Makkawi M, Shubayr N, Zaman G, Alashban Y, Eisa N, Khairy H, Rudiny F, Afif B. Assessing liver functions of radiologic technologists exposed chronically to radiation. Biomed Biotechnol Res J [serial online] 2021 [cited 2022 Jan 18];5:191-5. Available from: https://www.bmbtrj.org/text.asp?2021/5/2/191/318435
| Introduction|| |
The understanding of the potential effect of ionizing radiation (IR) on the human body among staff working in the radiation field continues to evolve. IR exposure can induce early and late biological effects on normal tissues and adversely affect human health. Several early studies have investigated the incidence of cancer among radiologic staff.,,,,,, Other studies on patients who have no liver disease and undergone radiation therapy have proven that IR exposure can induce hepatic dysfunction or liver cancer.,, Experimental studies have shown that exposing rats to a single dose of 6-Gy gamma radiation could induce a significant elevation in aspartate and alanine transaminase (AST, ALT), markers of liver function tests (LFTs). However, studies on the effect of radiation among radiologic technologists and radiologists remain limited. There is no doubt that exposing to high-dose IR is extremely dangerous, and there is a need for something to safeguard against it. The need for rules to control the usage of low dose IR in medical uses to protect radiologists, radiologic technologists, and patients from the excessive need for usage of radiology instruments. The linear no-threshold concept is a hypothetical model that is used currently to control the use of medical low-dose IR. Unfortunately, the proof of this hypothetical has never been right, as the results of the regulations were so tight that limit the development of the use of radiation. The association between radiation and cancer development in pre-1950s workers who were shown to be exposed to radiation was investigated in multiple studies. These studies showed that there is a risk of developing cancer like leukemia, breast cancer, melanoma, and skin cancer among radiologic technologists. The liver is considered a radiation-sensitive organ,, and the effects of chronic radiation exposure (low radiation dose over a long time) on the liver are unclear. Animal experimental data have suggested that a single radiation dose ranging from 0.02 to 1.0 Gy can induce liver inflammation and affect liver function, which can lead to the development of liver disease. Exposure to radiation chronically involved complex pathogenesis. This includes various organs such as the parenchyma, the connective tissue components, and the vasculature. Besides, the macrophages of the immune system comprise a major contribution in many instances. The number of medical radiologic technologists (RTs) is increasing globally, especially in Saudi Arabia. RTs are exposed to IR nearly daily in radiology departments. Due to the nature of their work in medical imaging, in some procedures, RTs may need to be physically close to the patients when radiation is being used. However, in some situations, such as radiography, mammography, and general computed tomography, personnel do not need to be physically close, which, in return, affords enough radiation protection.
LFTs are useful tests broadly used to evaluate the role of liver function in health and disease. The liver is responsible for several functions, including protein synthesis, erythrocyte synthesis and storage, metabolism, and production and regulation of digestive enzymes. The evaluation of the association between liver injury and long-term exposure to low IR doses below the threshold limit value has recently been studied. A study has observed that the risk of liver injury in industrial radiographers, who are chronically exposed to low-dose radiation, was higher than that in those not exposed to low-dose radiation. Interestingly, the same study did not find a relationship between cumulative radiation dose and liver injury.
Thus, this study investigates the risk factors for developing liver injury among selected RTs and evaluates the relationship between cumulative radiation dose and liver injury.
| Methods|| |
A retrospective analysis was performed on the effective cumulative radiation dose for a selected RTs from 2009 to 2019. Ethical approval (approval number: (ECM#2020-3201)-[HAPO-06-B-001]) was received by the Ethical Committee of Scientific Research, King Khalid University. The selected RTs were assured of the use of data for research purposes.
The study was carried out in the Department of Radiology, Sabya General Hospital, Jazan Region, Saudi Arabia Blood samples from RTs of Radiological Department, Sabia General Hospital, Ministry of Health, Saudi Arabia from August to October 2020. RTs group includes 10 RTs participants who have been working in the radiology field for more than 10 years. The chosen RTs (5 male and 5 female) aged between 30 and 45 years have the highest thermoluminescent dosimeters (TLDs) reading (235.85–323.72 uS) among all TLD measured volunteers. RTs group were compared to healthy group who had no history of health issues.
All RTs were provided personal bar-coded whole-body TLDs (containing the workers' name, age, and time of use) that are worn at the chest level under the lead apron. These TLDs are made of lithium fluoride materials doped with magnesium and titanium (LiF–Mg, Ti). The TLDs are read using a Harshaw 6600 Plus Automated Reader (Thermo Electron Corporation, Ohio, USA). This study focuses on the relationship between the cumulative radiation dose and the relative risk of liver injury.
Blood samples were collected from all RTs through venipuncture and placed in plain tubes without any anticoagulant for several biochemical tests. The serum was separated from the clot by centrifugation at 3,000 rpm for 10 min at room temperature. The clear supernatant was immediately transferred to another test tube and used for serum biochemical analysis. Biochemical tests including alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), total bilirubin (BiL), direct BiL, indirect BiL, albumin (ALB), total protein (TP), cholesterol (CHOL), triglyceride (TG), high-density lipoprotein (HDL), and glucose (GLUH) were measured using a fully automated biochemical analyzer (DXC 600; Beckman Coulter, California, USA).
For statistical analysis, GraphPad Prism was used for analyses (GraphPad Prism version 9.00 for Mac, GraphPad Software, San Diego CA). The Mann–Whitney U-test was used to compare irradiated participants with nonirradiated controls. To evaluate the degree of association between two variables, Spearman's correlation was used. P < 0.05 was used to denote statistical significance.
| Results|| |
The study focused on the association between prolonged IR exposure of the RTs and related risk of liver injuries. The result of the radiation dose analysis revealed that the average accumulated dose in 10 years is 7.6 mSv.
The total sample of 35 consisted of 25 control and 10 RTs. Mann–Whitney U-test (α =0.05) was used to compare the AST medians between the two groups. However, the results were not statistically significant. There is not enough evidence to conclude that the scores in the control group (M = 18; U = 124.5; P value = 0.9930) were any different from those in the RTs group (M = 18.50; U = 124.5; P value = 0.9930) [Figure 1]. The median ALT value in the control and RTs groups was statistically compared using Mann–Whitney test at α =0.05 [Figure 2]. The results suggest that the median scores in the control (M = 13.00; U = 107.5; P value = 0.5331) and RTs groups (M = 14.17; U = 107.5; P value = 0.5331) were not significantly different. Moreover, the median ALP value [Figure 3] in the control and RTs groups was compared and no significant difference was observed in the control (M = 51.00; U = 97; P value = 0.3161) and RTs (M = 56.17; U = 97; P value = 0.3161) groups.
|Figure 1: The effect of radiation exposure on AST among radiologic technologists (RTs). The total sample of 35 consisted of 25 control workers and 10 RTs|
Click here to view
|Figure 2: The effect of radiation exposure on ALT among radiologic technologists (RTs). The total sample of 35 comprised 25 control workers and 10 RTs|
Click here to view
|Figure 3: The effect of radiation exposure on ALP among radiologic technologists (RTs). The total sample of 35 comprised 25 control workers and 10 RTs|
Click here to view
The median GGT in the control (n = 25) and RTs (n = 10) groups was compared α =0.05 [Figure 4] and the results suggest that the median scores in the control group scores (M = 10.0; U = 51.50; P value = 0.0206) were significantly less than those in the RTs group ((M = 14.0; U = 51.50; P value = 0.0206). Other biochemical LFTs including total BiL, direct BiL, indirect BiL, ALB, TP, CHOL, TG, HDL, and GLUH, were statistically analyzed and are shown in [Table 1]. However, no statistical differences (P > 0.05) were observed between the two groups.
|Figure 4: The effect of radiation exposure on GGT among radiologic technologists (RTs). The total sample of 35 comprised 25 control workers and 10 RTs|
Click here to view
|Table 1: Effect of radiation exposure on liver function tests among radiological technologists|
Click here to view
| Discussion|| |
Chronic exposure to either high or low doses of radiation is of medical radiologic technologist's interests. Consequently, further studies are required in examining the adequacy of current radiation protection measures and to provide optimal protection procedures to determine the risk of radiation among professions exposed to chronic radiation if necessitated. Our study was designed to peruse the risk factors contributing to the development of liver dysfunction among selected RTs who have continuous radiation exposure. The study has examined the relationship between liver dysfunction and long-term use of low-dose IR below the threshold level. To the best of our knowledge, this is a rare study that compares liver dysfunction between medical RTs who are chronically exposed to IR and a control group, which has been endeavored for the first time in Saudi Arabia.
Our study is consistent with the study carried out by Sun et al. in 2018, who have noted that cumulative radiation dose and liver injury have no significant association. In Sun et al.'s study, the associations between protracted low-dose radiation exposure and liver injury were assessed considering several factors such as age, gender, alcohol consumption, smoking, and the presence of hypertension and diabetes. However, in our study, the targeted population consisted of medical radiographers who were chronically exposed to IR in a manner similar to industrial radiographers. The selection of RTs who are nonalcoholic (no consumption regardless of the quantity), nonsmoker, and who have no medical history of hypertension and diabetes was proposed to investigate the risk factors related to radiation without considering other factors that could contribute to liver injuries.
Our study examined the hallmark laboratory parameters for liver function to investigate the toxicity of radiation on the liver. Despite there were no statistical differences between RTs and Control groups. The difference in the medians of the GGT level between the control and RTs groups was statistically significant. It showed that median scores in the control group were significantly less than those in the RTs group. The biomarker GGT is routinely used to evaluate liver function. GGT is synthesized by both the hepatocytes and epithelial cells present in the intra-hepatic bile ducts., Although it is associated with chronic alcoholism, it has also been found to be elevated in metabolic syndrome,, oxidative stress,, stenosis of the coronary artery, and chronic kidney disease. Recently, GGT reported to increasing the rate of radiation-induced hepatic toxicity among patients with hepatocellular carcinoma following treatment with stereotactic body radiotherapy. In addition, GGT was noticeably upregulated by radiation and showed a significant 2–3-fold increase using rat colon carcinoma CC531 cells. Elevation of GGT following radiation was reported due to activation of two Ras isoforms including H-Ras and K-Ras. Ras signal transduction pathway upregulates GGT activity and contributes to radioresistance. Interestingly, in agreement with the prior study, Ras might mediate the upregulation of GGT among RTs.
| Conclusion, Limitations and Recommendations|| |
The risk of developing hepatic injury among the selected group of RTs remains low. Although the dramatic variation in the GGT marker was statistically notable. The engagement between irradiation and upregulation of GGT in our study was proposed, but yet to be determined. Lacking the sample size for statistical measurement limited the study. However, conducting such a study on a large cohort is of interest, but hardily achievable.
The authors are grateful to Dr. Saeed Mastour for his statistical suggestions.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Dörr W. Radiobiology of tissue reactions. Ann ICRP 2015;44:58-68.
Parikh JR, Geise RA, Bluth EI, Bender CE, Sze G, Jones AK, et al.
Potential radiation-related effects on radiologists. Am J Roentgenol 2017;208:595-602.
Ulrich H. The incidence of leukemia in radiologists. N Engl J Med 1946;234:45.
March HC. Leukemia in radiologists. Radiology 1944;43:275-8.
Linet MS, Freedman DM, Mohan AK, Doody MM, Ron E, Mabuchi K, et al.
Incidence of haematopoietic malignancies in US radiologic technologists. Occup Environ Med 2005;62:861-7.
Doody MM, Freedman DM, Alexander BH, Hauptmann M, Miller JS, Rao RS, et al.
Breast cancer incidence in U.S. radiologic technologists. Cancer 2006;106:2707-15.
Freedman DM, Sigurdson A, Rao RS, Hauptmann M, Alexander B, Mohan A, et al.
Risk of melanoma among radiologic technologists in the United States. Int J Cancer 2003;103:556-62.
Yoshinaga S, Hauptmann M, Sigurdson AJ, Doody MM, Freedman DM, Alexander BH, et al.
Nonmelanoma skin cancer in relation to ionizing radiation exposure among U.S. radiologic technologists. Int J Cancer 2005;115:828-34.
Rösler P, Christiansen H, Kortmann RD, Martini C, Matuschek C, Meyer F, et al.
Hepatotoxicity after liver irradiation in children and adolescents: Results from the RiSK. Strahlenther Onkol 2015;191:413-20.
Stryker JA. Science to practice: Why is the liver a radiosensitive organ? Radiology 2007;242:1-2.
Bakshi MV, Azimzadeh O, Barjaktarovic Z, Kempf SJ, Merl-Pham J, Hauck SM, et al.
Total body exposure to low-dose ionizing radiation induces long-term alterations to the liver proteome of neonatally exposed mice. J Proteome Res 2015;14:366-73.
Abd El-Azime AS, Hussein EM, Ashry OM. Synergestic effect of aqueous purslane (Portulaca oleracea
L.) extract and fish oil on radiation-induced damage in rats. Int J Radiat Biol 2014;90:1184-90.
Høilund-Carlsen PF. The good rays: Let them shine! Eur J Nucl Med Mol Imaging 2019;46:271-5.
Shubayr N, Alashban Y, Almalki M, Aldawood S, Aldosari A. Occupational radiation exposure among diagnostic radiology workers in the Saudi ministry of health hospitals and medical centers: A five-year national retrospective study. J King Saud Univ Sci 2021;33:101249.
Le Heron J, Padovani R, Smith I, Czarwinski R. Radiation protection of medical staff. Eur J Radiol 2010;76:20-3.
Gowda S, Desai PB, Hull VV, Math AA, Vernekar SN, Kulkarni SS. A review on laboratory liver function tests. Pan Afr Med J 2009;3:17.
Lala V, Goyal A, Bansal P, Minter DA. Liver Function Tests. StatPearls Treasure Island (FL): StatPearls Publishing; 2020.
Sun Q, Mao W, Jiang H, Zhang X, Xiao J, Lian Y. The effect of protracted exposure to radiation on liver injury: A cohort study of industrial radiographers in Xinjiang, China. Int J Environ Res Public Health 2018;15:71.
Nemesánszky E, Lott JA. Gamma-glutamyltransferase and its isoenzymes: Progress and problems. Clin Chem 1985;31:797-803.
Joyce-Brady M, Takahashi Y, Oakes SM, Rishi AK, Levine RA, Kinlough CL, et al.
Synthesis and release of amphipathic gamma-glutamyl transferase by the pulmonary alveolar type 2 cell. Its redistribution throughout the gas exchange portion of the lung indicates a new role for surfactant. J Biol Chem 1994;269:14219-26.
Liu C, Zhou WN, Fang NY. Gamma-glutamyltransferase levels and risk of metabolic syndrome: A meta-analysis of prospective cohort studies. Int J Clin Pract 2012;66:692-8.
Kunutsor SK, Apekey TA, Seddoh D. Gamma glutamyltransferase and metabolic syndrome risk: A systematic review and dose-response meta-analysis. Int J Clin Pract 2015;69:136-44.
Lee DH, Blomhoff R, Jacobs DR Jr. Is serum gamma glutamyltransferase a marker of oxidative stress? Free Radic Res 2004;38:535-9.
Lim JS, Yang JH, Chun BY, Kam S, Jacobs DR Jr., Lee DH. Is serum gamma-glutamyltransferase inversely associated with serum antioxidants as a marker of oxidative stress? Free Radic Biol Med 2004;37:1018-23.
Arasteh S, Moohebati M, Avan A, Esmaeili H, Ghazizadeh H, Mahdizadeh A, et al.
Serum level of gamma-glutamyl transferase as a biomarker for predicting stenosis severity in patients with coronary artery disease. Indian Heart J 2018;70:788-92.
Shen Z, Xing J, Wang QL, Faheem A, Ji X, Li J, et al.
Association between serum γ-glutamyltransferase and chronic kidney disease in urban Han Chinese: A prospective cohort study. Int Urol Nephrol 2017;49:303-12.
Song JH, Jeong BK, Choi HS, Jeong H, Lee YH, Kim HJ, et al.
Defining radiation-induced hepatic toxicity in hepatocellular carcinoma patients treated with stereotactic body radiotherapy. J Cancer 2017;8:4155-61.
Pankiv S, Møller S, Bjørkøy G, Moens U, Huseby NE. Radiation-induced upregulation of gamma-glutamyltransferase in colon carcinoma cells is mediated through the Ras signal transduction pathway. Biochim Biophys Acta 2006;1760:151-7.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]