The Prevalence of Thyroid Nodularity in Saudi Radiographic Technologists
College of Applied Medical Science, Radiological Science Department, Taif University, Taif, KSA
Taif Central Office, P.O.Box: 1953, Postal Code: 21944, Taif, KSA
Email: [email protected]
Running Title: Prevalence of Thyroid Nodularity
Objective: The study is mainly concerned with the prevalence of thyroid nodules among the Saudi radiographic technologists, being exposed to x-ray radiation within the hospital setting. Methods: The study has incorporated prospective approach and recruited a total of 100 Saudi volunteers’ radiographic technologists’ males and females from Radiology Department in KSA Hospitals. The study was conducted between January 2017- June 2017. Thyroid gland of each participant was scanned by ultrasound. Results: Thyroid nodules appeared in 34 out of 100 patients with a ratio of 2:1 between female and male. The mean age of all the participants was 39.7 years; however, the prevalence of thyroid nodules was greater among the participants with age of more than 45 years (58.83%). Statistically significant association was observed between development of thyroid nodules and age (P. value < 0.05). Moreover, there was statistically significant association between development of thyroid nodule and occupational exposure to ionization radiation (P. value < 0.05). The echo abnormality represented solitary among 14 subjects (41.18%), multiple in 7 (20.59%), and diffuse in 13 (38.23%) participants. Conclusion: The study concluded that risk of developing thyroid nodule increased as a result of prolonged exposure to low-dose ionization radiation. Radiographic technologists need to use proper safety precautions when dealing with ionizing radiation in radiology departments.
Keywords: Occupational Exposure, Radiographic Technologist, Thyroid Nodules
Thyroid gland functions maintain the physiological activities of different body organs. In the clinical practice, enlargement of thyroid gland is considered as a common problem, which is usually detected through ultrasound 1. Thyroid nodule, appears as a discrete lesion within the thyroid gland, is diagnosed through Magnetic Resonance Imaging (MRI) and Computed Topography (CT). Thyroid nodules may be presented as a symptom of other diseases. Ultrasound is considered as a fast and safe method for detecting thyroid nodules among general population 2. The development of thyroid nodules is likely to increase with age and chronic exposure to ionization radiation. It has also been shown that women as compared to men are 10 times more likely to develop problems related to thyroid gland 3. The prevalence of developing thyroid nodules varies on the basis of target population as well as the technique that is used for detecting the nodules. It is a well-established fact that the risk of developing thyroid nodule increase if an individual is suffering from severe iodine deficiency 4.
The ultrasound machines currently used are sensitive, less-expensive, and user friendly; therefore, ultrasonography is known as a cost-effective method to detect the presence of thyroid nodules. Most endocrinologists are now using ultrasound examination in the initial evaluation of a patient with known or suspected thyroid nodule 4. The technique of ultrasonography is effective in detecting nodules that are too small to be diagnosed through palpation. The studies conducted by Papini et al. 5 and Fish et al. 6 have demonstrated that ultrasonography is effective in diagnosing multiple nodules and lateral neck lymphadenopathy. The interval monitoring is supported by obtaining accurate measurements of nodule diameter 5,6.
The development of thyroid nodules is extensively observed among irradiated individuals. Thyroid lesions have been classified into solitary nodule, multi-nodule, and diffuse goiter on the basis of clinical examination and non-invasive techniques. The ultrasound machine is capable of detecting small nodules due to its increased resolution. Regression of nodules have been observed among the patients taking medication. The study conducted by Dan et al 7 has shown that Fine Needle Aspiration of the thyroid nodules is not viable among the irradiated patients; therefore, ultrasound helps in the identification of growing nodules within the thyroid gland.
Few studies have shown increased prevalence of nodule and cancer formation among the infants and adolescents, who are being exposed to ionization radiation 8-12. However, a study conducted by Betul et al. 13 has revealed that the risk of developing thyroid cancer increases among the individuals, who are exposed to external radiation for treating benign or malignant tumor near the head or neck area. The impact of long-term occupational exposure to ionization radiation has been examined by limited studies 14-16. Therefore, this study mainly focuses on investigating the prevalence of thyroid nodules among Saudi radiographic technologists, who are exposed to occupational ionization radiation within hospitals.
Materials and Methods
The study has selected 100 Saudi radiographic technologists’ (male and female) working in different x-ray departments randomly. Participants were occupationally exposed to ionized radiation and have not exceeded the maximum permissible dose “5 rem/annual”, according to their annual exposure reports. All participants, who had occupational exposure to x-rays of more than 10 years, were included in the survey; however, less than 10 years was excluded. Participants were subdivided with respect to age, sex, years of occupational exposure to x-rays. A real-time thyroid ultrasonography machine based on direct contact technique was used for scanning thyroid gland of each participant. This instrument helped in recording the size, position, symmetry, texture, nodularity, and echogenicity of the thyroid gland.
The purpose of the study was explained to all the participants and the study proceeded after obtaining permissions from hospital management. The study was conducted according to the Declaration of Helsinki as revised in 2000. Special consideration was given to the right to confidentiality and anonymity of all survey participants. Anonymity was achieved by using numbers for each survey participant that will provide link between the information collected and the participants. The confidentiality was ensured by making the collected data accessible only to the researcher. The right to equality was ensured by giving each participant the same number and type of ultrasound and laboratory procedures. Justice and human dignity were observed by treating selected participants equally, when offering them an opportunity to participate in the survey. The participants were free to decide whether to participate or not. Participants who agreed for participation were given informed consent. The data was analyzed using Statistical Package of Social Sciences (SPSS) version 20.0 and the results were presented in the form of mean and standard deviation. Significant differences between different groups were detected through one-way ANOVA test at significance level 0.05.
Thyroid nodularity was present among 34 subjects. The ratio of thyroid nodularity between female and male was 2:1. Twenty-three females (67.6%) developed a degree of thyroid nodularity as compared to males (32.35%) (Table 1).
Insert Table 1 here
Ages of the participants were divided into 3 groups; A, B and C, with interval of ±10 years range. The mean age for the participants was 39.7 years. In group A, only 2 (5.88%) participants reported a degree of thyroid nodularity. Group B showed increase in thyroid nodularity 12 (35.29%). Group C, revealed the highest prevalence of thyroid nodularity. Table 2 has clearly depicted that there was a statistically significant association between age of the patient and development of thyroid nodules (P. value ; 0.05) (Table 2).
Insert Table 2 here
Considering the duration of occupational exposure in years, participants were stratified in 4 groups A, B, C and D with interval ±5 years range (Table 3). Long-term occupational exposure to radiation increases the prevalence of thyroid nodules. The results have shown statistically significant association between occupational exposure to radiation and development of thyroid nodules among the individuals. The echo abnormalities in Table 4 comprise of three types of thyroid nodules; solitary, multiple, and diffuse (41.18%, 20.59%, and 38.23%, respectively). There was a statistically insignificant association between age and thyroid echo findings (P. value=0.286).
Insert Table 3 here
Insert Table 4 here
In the present study, the prevalence of thyroid nodules among Saudi radiographic technologists has been studied on randomly selected participants by ultrasonography exposed occupationally to x-rays for more than 10 years. Saudi radiographic technologists have been increasing gradually as more graduates were graduated in different faculties in Kingdom of Saudi Arabia in the field of radiography. Being a rare disease, thyroid nodule tends to represent an intermediate endpoint relating to the development of thyroid cancer 17. Occupational radiation dose describes the limits of radiation for adult workers applied to any combination of dose received from external or internal exposure 18.
In the present study, 34% participants develop thyroid nodules, which are consistent with the results of study, conducted by Alessandro et al 19. According to the study, it was obvious that occupational exposure to ionizing radiation is a significant risk factor for the development of thyroid nodules 19. Moreover, other risk factors have increased the prevalence of developing thyroid nodules include; older age, gender, and iodine deficiency 21. The impact of long term exposure to low dose ionization radiation has been reported by few studies 12, 14-16, 19. However, majority of the studies have reported increased prevalence of developing thyroid nodules and cancer among the professionals, who are exposed to ionization radiation. Amin et al. 20 conducted a study to reveal the risk factors resulting in development of thyroid nodules. The results depicted that risk of thyroid nodules may increase even if the individual uses protective measures, while performing his duty 20. This clearly depicts that doubt related to development of thyroid nodules as a result of being exposed to ionization radiation is still enduring.
In the past few decades, Saudi Arabia development program was providing an inequity between males and females education especially in health sciences. It resulted in increased number of female radiation workers, developing some kind of thyroid nodules compared to male. This is consistent with the present study, in which 67.65% of the participants from the total participants reported that female radiologic technologists have thyroid nodules. These results are consistent with Boice 12, who reported that 76% of female radiologic technologists had thyroid nodules.
The prevalence of nodule among males and females is likely to increase with age; therefore, age is considered among the important risk factors contributing towards the formation of thyroid nodule 22. The increased prevalence of developing thyroid nodule was observed among the individuals with age greater than 45 years 58.83%. Moreover, it was also observed that individuals being exposed to radiation for more than 25 years were at increased risk of developing thyroid nodules. Present study has shown statistically significant relationship between thyroid nodule formation and duration of occupational exposure to ionization radiation. On the contrary, a study conducted by Atoosa et al. 23 showed no association between the increased risk of developing thyroid nodules and chronic occupational exposure to ionization radiation.
A study conducted by Nikiforov 24 specified the influence of ionization radiation on the thyroid gland that is likely to result in the formation of thyroid nodules and thyroid cancer. The study also showed that papillary carcinoma is considered as the most common type of thyroid cancer resultant from chronic exposure to ionization radiation 24. Increased dose of ionization radiation tends to produce harmful effects on an individual’s health such as cancer induction. The results have also shown that acute exposure to ionization radiation imposes harmful impact on an individual’s body as compared to chronic exposure to ionization radiation. The association between formation of thyroid nodule and occupational exposure to ionization radiation has not been proved yet. However, some of the studies have shown increased prevalence of nodule formation among the individuals, who are being exposed to radiation every day because of their occupation 27-31. It is also believed that ionization radiation cannot be considered as an individual factor leading to the development of nodules or benign pathologies.
The echo abnormality represented solitary among 14 subjects (41.18%), multiple in 7 (20.59%) and diffuse in 13 (38.23%) participants. The study conducted by Brander et al. (32), reported solitary among 57% respondents; diffuse among 22% respondents, and multiple among 22% respondents. The results concluded increased prevalence of abnormalities related to small thyroid echo among random adult individuals.
The study has concluded that prolonged low-dose exposures to ionizing radiation may cause an increase in the risk of thyroid nodules. Radiographic technologists are required as safety aspect when dealing with ionizing radiation in radiology departments. However, argument about the risk of occupational exposure to radiation and developing thyroid nodules is not enough. It is important to characterize the risk factors associated with low dose-rate exposure to ionizing radiations through follow ups among the Saudi radiographic technologists. These technicians are instructed to wear a personal dosimeter during their working hours. Applying the basic principles of radiation protection as radiation protectors (thyroid choler shielding, dose and area monitoring, distance and proper equipment handling) is likely to reduce the exposure of radiographic technologists.
The author is very thankful to all the associated personnel in any reference that contributed in/for the purpose of this research.
Conflict of Interest
The research has no conflict of interest and is not funded through any source.
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Table 1: Distribution of thyroid nodularity by gender in Saudi radiographic technologists
Gender With nodules Without nodules
Male 11(32.35 %) 39 (59.00%)
Female 23(67.65 %) 27 (41.00%)
Total 34(34.00%) 66 (66.00%)
Table 2: Distribution of thyroid nodularity by age in Saudi radiographic technologists
Age Group With nodules
? 35 A 2 (5.88%)
36-45 B 12 (35.29%)
; 45 C 20 (58.83%)
Table 3: Distribution of thyroid nodularity by duration of occupational exposure in Saudi radiographic technologists
Duration of Occupational Exposure (years) Group With nodules
;10 A 2 (5.88%)
11-15 B 8 (23.52%)
16-25 C 11(32.35%)
;25 D 13(38.23%)
Table 4: Thyroid Echo Abnormalities
Thyroid Echo Abnormalities Frequency Percentage
Solitary 14 41.18
Multiple 7 20.59
Diffused 13 38.23
Total 34 100