Electronic Journal of Biology

Keywords

Radiobiology; Cancer; Radiologists; Knowledge; Dose

1. Introduction

Radiation and associated biological effects have been documented over decades. Ionizing radiation like computed tomography (CT) was associated with increased incidence of cancer [1-5]. CT scan is considered one of the most routinely used imaging modality. Accordingly, most cancer cases in the United States were linked to the CT examinations due to increased radiation dose. It was estimated that every 1000 scanned patients, there is one cancer incidence. However, cancer risk has been reported at high radiation dose level and its link with low dose level needs more evaluation [6-9]. Radiologists play an important role in the diagnosis process of patients. Their knowledge of radiation doses and associated biological effects is necessary in selecting the optimal diagnostic imaging test in terms of minimal required radiation dose and acceptable image quality [10,11]. The level of knowledge and understanding of radiation protection can be influenced by the radiologist license requirements. In Jordan, a radiologist is required to pass the Jordanian board of radiology after successful completion of radiology training in a recognized hospital. However, radiation safety training program attendance is optional. In comparison to other countries such as USA, radiation safety is a core exam in the American board of radiology [12]. Therefore, differences between countries can create variation in the knowledge level. In order to assess the knowledge level, several studies from different countries were conducted. A study was performed in Hong Kong and reported unsatisfactory knowledge level among radiologists and recommended a training on radiation associated risks [1]. Another study was conducted in 5 hospitals in London and found a lack of knowledge on radiation doses and risks [11]. Most of the studies reported lack of knowledge and insufficient understanding of radiation biological effects [13-20].

The aims of this study were to assess the knowledge level of radiologists about understanding the relationship between radiation dose level and possible biological effects, and to test whether experience and training courses can affect the knowledge level.

2. Methods

This study was approved by the institutional review board at Jordan University of Science and Technology. An expert radiographer distributed the questionnaire over 4 main local hospitals. Radiologists from all departments; including routine x-ray imaging, angiography, CT, fluoroscopy, magnetic resonance imaging (MRI), ultrasound (US) and nuclear medicine (NM) were invited to participate in the study. After explaining the aims of the research and obtaining the consent forms, participants were asked to fill out the questionnaire. The questionnaire included demographic information section, general radiation protection section, radiation dose section, and radiation induced cancer risk section. Questions in general radiation protection section were selected to evaluate the general knowledge and the understanding of background radiation exposure in comparison to medical X-ray radiation exposure, ionizing and non-ionizing radiation types and radiosensitviy of children biological organs. Questions in radiation dose section were designed to assess the ability of radiation dose estimation of common radiological examination in comparison to the dose of one chest X-ray. Lifetime cancer risks of common radiological examination questions in the radiation induced cancer risk section were provided to evaluate the understanding of cancer risk from different radiation doses. This knowledge can improve the communication between radiologists and patients about explaining the radiation risks of radiological examinations. The questions were adopted from previous published questionnaires [7,14,20]. The questionnaire was available in Arabic and English versions.

For statistical analysis, two values were assigned for grading the answers; 1 for correct answer and 0 for incorrect answer. For each subject, total score of all sections (17 questions) and individual section scores were calculated as percentage (total correct answers divided by total number of questions). Then, mean scores and standard error (SE) were calculated. Oneway ANOVA was used to test significant difference between individual section scores and Student's t-test was used to test significant difference between trained and untrained subject scores. The difference was considered significant if p-value was less than or equal to 0.05. Pearson’s correlation coefficient was calculated to test the correlation between the experience and the questionnaire scores. Statistical analysis was performed using Prism 5 (GraphPad, La Jolla, CA, USA).

3. Results

A total of 23 radiologists agreed to participate in this study. Demographic information is summarized in Table 1. The mean total score of all sections was 59%. Among individual sections, the lowest mean score was for radiation induced cancer section (55%). However, there was no significant difference between scores (p=0.4). The questionnaire score results are summarized in Table 2. Radiologists who carried out training courses scored higher than radiologists without training courses (61%, 54%, respectively). Table 3 summarizes the results of trained and untrained subjects. Experience in years (5.1 ± 0.9) neither correlated significantly with the total score nor with the score of individual sections. Table 4 summarizes the correlation test results (Appendix).

Table 1. Summary of demographic information of participants.

Table 2. Summary of questionnaire scores.

Table 3. Summary of trained and untrained scores.

Table 4. Summary of correlation test results between questionnaire scores and experience.

4. Discussion

Radiobiology is an important area of science for radiologists who are engaged with medical examinations involving radiation exposure that can result in adverse biological effects to patients. In order to justify exposure of patient to radiation, they need to have an acceptable level of knowledge of radiation dose and biological effects. Accordingly, this study aimed to test their knowledge level in different areas of this field including general radiation protection section, radiation dose estimation section and radiation induced cancer section.

The results indicated an overall inadequacy of knowledge (59%). The lowest obtained score (55%) was for radiation induced cancer section. This section measured the ability of radiologists to differentiate between imaging modalities that are associated with different level of radiation doses to induce cancer. Although trained radiologists scored higher than untrained radiologists, the difference was not significant. A study was conducted among cardiologists to examine their knowledge of radiation protection before and after training course [19]. An improvement of their score was recorded after attending the training. Experience did not show to have a significant improvement on the scores. This was similar to study conducted in U.S. academic medical center found that most of radiologists were unable to accurately estimate the dose for one CT scan compared with that for one chest radiograph regardless their experience level [13]. The results were similar to previous studies that tested the knowledge level among physicians and radiologists. A survey was conducted of the awareness of radiation dose and risk among health professionals in Northern Ireland [7]. Their results confirmed that clinician awareness of radiation doses and the consequent risk to the individual patient is poor. They recommended clinicians to have more education about ionizing radiation relevant to medical imaging.

This is the first study to report knowledge level of radiobiology among radiologists in Jordan. Although the sample size is not large enough, the results can establish a baseline for future studies to include more hospitals from private and governmental sectors.

5. Conclusion

Lack of radiobiology knowledge can impact the important role of radiologist in patient imaging justifications. Training courses are recommended to improve the knowledge of radiobiology among radiologists especially in the area of radiation induced caner. Future studies are recommended to engage physicians from different departments who are involved in referring patients to radiology department.

6. Acknowledgement

We would like to thank the hospitals for the participation and their cooperation during our study. Thanks to Hamza Almasri and Majd Alkhaleli for their help in distributing the questionnaires and collecting the data.

7. Funding

This work was funded by Jordan University of Science and Technology (Grant number: 20120222).

8. Competing and Conflicting Interest

No competing interests exist.

References

1. Wong C, Huang B, Sin H, et al. (2012). A questionnaire study assessing local physicians, radiologists and interns’ knowledge and practice pertaining to radiation exposure related to radiological imaging. Eur J Radiol. 81: 264-268.
2. Maeder M, Verdun F, Stauffer J, et al. (2005). Radiation exposure and radiation protection in interventional cardiology. Kardiovaskuläre Medizin. 8: 124-132.
3. Brenner D, Hall E. (2007). Computed Tomography — An Increasing Source of Radiation Exposure. N Engl J Med. 357: 2277-2284.
4. Yu S, Cheung Y, Chan T, et al. (2001). Reduction of radiation dose to patients undergoing barium enema by dose audit. Br J Radiol. 74: 162-165.
5. Hall E, Brenner D. (2008). Cancer risks from diagnostic radiology. Br J Radiol. 81: 362-378.
6. Baumann B, Chen E, Mills A, et al. (2011). Patient perceptions of computed tomographic imaging and their understanding of radiation risk and exposure. Ann Emerg Med. 58: 1-7.
7. Soye J, Paterson A. (2008). A survey of awareness of radiation dose among health professionals in Northern Ireland. Br J Radiol. 81: 725-729.
8. Brenner D, Doll R, Goodhead D, et al. (2003). Cancer risks attributable to low doses of ionizing radiation: Assessing what we really know. Proc Natl Acad Sci U S A. 100: 13761-13766.
9. Thomas K, Parnell J, Haidar S, et al. (2006). Assessment of radiation dose awareness among pediatricians. Pediatr Radiol. 36: 823-832.
10. Li X, Samei E, Segars W, et al. (2011). Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients. Med Phys. 38: 408-419.
11. Koutalonis M, Horrocks J. (2012). Justification in clinical radiological practice: a survey among staff of five London hospitals. Radiat Prot Dosimetry. 149: 124-137.
12. The American board of radiology. Available: https://www.theabr.org/ic-dr-core-exam. Accessed 11 May 2016.
13. Lee C, Haims A, Monico E, et al. (2004). Diagnostic CT Scans: Assessment of patient, physician, and radiologist awareness of radiation dose and possible risks. Radiology. 231: 393-398.
14. Eksioglu A, Uner C. (2012). Pediatricians' awareness of diagnostic medical radiation effects and doses: are the latest efforts paying off? Diagn Interv Radiol. 18: 78-86.
15. Mojiri M, Moghimbeigi A. (2011). Awareness and attitude of radiographers towards radiation protection. JPS. 2: 2008-4978.
16. Shah A, Begum N, Nasreen S, et al. (2007). Assessment of radiation protection awareness levels in medical radiation science technologists - a pilot survey. JPMI. 21: 169-172.
17. Osullivan J, Oconnor O, Oregan K, et al. (2010). An assessment of medical students’ awareness of radiation exposures associated with diagnostic imaging investigations. Insights Imaging. 1: 86-92.
18. Sani K, Jafari M, Mohammadi M, et al. (2009). Iranian physicians' knowledge about radiation dose, received by patients in diagnostic radiology. Iran. J. Radiat. Res. 6: 207-212.
19. Carpeggiani C, Kraft G, Caramella D, et al. (2012). Radioprotection (un)awareness in cardiologists, and how to improve it. Int J Cardiovasc Imaging. 28: 1369-1374.
20. Luk S, Leung J, Cheng C. (2010). Knowledge of radiation dose and awareness of risks: a cross-sectional survey of junior clinicians. J Hong Kong Col Radiol. 13: 189-194.