Tejavathi Nagaraj, N. Sreelakshmi, Leena James, Bhavana T. Veerabasaviah, Rahul Dev Goswami, Lakshmi Balraj

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1 Journal of Medicine, Radiology, Pathology & Surgery (2016), 3, 5 9 ORIGINAL ARTICLE An assessment of knowledge and perception of postgraduate students and interns toward radiation protection protocols: A questionnaire-based study in dental colleges Tejavathi Nagaraj, N. Sreelakshmi, Leena James, Bhavana T. Veerabasaviah, Rahul Dev Goswami, Lakshmi Balraj Department of Oral Medicine and Radiology, Sri Rajiv Gandhi College of Dental Sciences and Hospital, Cholanagar, Hebbal, Bengaluru, Karnataka, India Keywords: Interns, PG students, radiation, radiation protection, X-rays Correspondence: Dr. Sreelakshmi N, Department of Oral Medicine and Radiology, Sri Rajiv Gandhi College of Dental Sciences and Hospital, Cholanagar, Hebbal, Bengaluru , Karnataka, India. Phone: sreelakshmi.11.n@gmail.com Received: 20 th June 2016; Accepted: 28 th July 2016; doi: /ins.jmrps.67 Abstract Background: Recognition of the harmful effects of radiation and the risks involved has led to the development of radiation protection protocols and guidelines. Aims and Objectives: To assess the knowledge and perception of postgraduate students and interns toward radiation protection protocols in dental colleges. Materials and Method: This study was conducted among 200 individuals (Equal number of interns and PG students). Each participant was given a structured questionnaire (with 20 questions). Answers to the questions were in the form of multiple choices. Correct responses to the questions were allocated one mark while wrong responses received no mark. First 10 questions were to evaluate the knowledge of dental students in radiation biology and remaining ten questions were to assess how well the participants were correlating their knowledge to practice dental radiography. Results: The knowledge and perception level in regard to radiation biology and radiation protection protocols were noted to be higher with postgraduate students than in the interns. Conclusion: The majority of interns and minority of postgraduate students had limited knowledge about various aspects of radiation biology and radiation protection protocols, and they should implement recent and appropriate radiation protection practices and guidelines. This helps in protection of both the patients and operator from the harmful effects of radiation. Introduction Radiation can be defined as the emission and propagation of energy through space or matter in the form of waves or particles. [1] The type of radiation that has sufficient energy to remove orbital electron from an atom is called as ionizing radiation. [2] X-rays are a type of ionizing radiation. They are used extensively in medical and dental field for diagnosis and therapeutic purposes. [2] Even though they are useful, X-rays have the potential to cause harmful effects and is liable to cause cancer and genetic damage. [3] The biologic effects of radiation can be divided into two categories namely deterministic and stochastic effects. Deterministic effects are dose-related effects of radiation. The stochastic effects are those for which the chance for occurrence of any change, rather than its severity is dependent on dose. [1,4] Hence, a dentist should exercise professional judgment, i.e., diagnostic radiography should be used only if necessary after thorough history taking and clinical examination. [5] The principle of radiation protection is to do those things that will minimize exposure of patient, dental personnel, public and still provide benefits for the patient from use of dental radiography. [2] For following this principle, a dentist should have thorough knowledge in radiation hazards and its protection protocols. The knowledge related to radiation is provided to all dental students during undergraduate training in dental colleges. Eventually, these dental students will start performing dental radiography in their clinics. Hence, their knowledge in radiation biology and radiation protection protocols are very essential. [6] Journal of Medicine, Radiology, Pathology & Surgery Vol. 3:5 Sep-Oct

2 Nagaraj, et al. Knowledge and perception toward radiation protection protocols Aim of the study To assess the knowledge and perception of postgraduate students (PG students) and interns toward radiation protection protocols in dental colleges. Materials and Methods This cross-sectional study on radiation protection was conducted during the time period 3-month (November 2014-January 2015) in some dental colleges in Bengaluru. The study sample consisted of 200 individuals (with 100 PG students and 100 interns). Participants were randomly selected. A selfprepared questionnaire was given to them. The participants were told to answer the questions and were not allowed to discuss the matters in the questionnaire. The questionnaires consisted of 20 questions. First 10 questions were to evaluate the knowledge of dental students in radiation biology and remaining questions were to assess how well the participants were correlating their knowledge to practice on dental radiography [Tables 1 and 2]. The responses were collected within 30 min. Method of statistical analysis The following methods of statistical analysis have been used in this study. The responses obtained from the participants were computed into a Microsoft excel worksheet and analyzed using SPSS (Statistical Package for Social Science, Ver ) package. 1. Univariate analyses of the dichotomous variables encoded were performed using the Chi-square test with Yates correction if required. 2. Student t-test. Results The study was conducted among 200 participants of which 100 were PG students, and 100 were interns. The overall correct responses given by PG students and interns was 75.5% and 55.5%, respectively, for the questions given to assess knowledge and was 80% and 65.5%, respectively, for the questions given to assess perception [Figure 1 and Table 3]. The percentage of correct responses given for each question is as given in Table 4. Table 1: The questionnaire given to the participants to assess knowledge in radiation biology 1. X ray cause cell death by a) Ionisation b) Penetration c) Don t know 2. Cells most susceptible to radiation are a) Highly differentiated cells b) Primitive cells c) Don t know 3. Most radio sensitive site in a cell a) DNA b) Cytoplasm c) Don t know 4. Most radio sensitive site in a following? a) Basal cells of oral mucosa b) Acinar cells of salivary gland c) Don t know 5. X ray if directed toward the eyes a) Damages optic lens b) Do not damage optic lens c) Don t know 6. Position distance rule means a) Positioning the patient at maximum distance away from the X ray source to reduce exposure b) If X ray barrier is not available, dentist should stand 6 feet from patient at an angle of from X ray source c) Don t know 7. Least radiation exposure is achieved with a) Rectangular collimator b) Circular collimator c) Don t know 8. Long source film distance: a) Increase exposure b) Decrease exposure c) Don t know 9. Total exposure for an orthopantomograph is less compared to that of full mouth periapical radiograph 10. Unit of measurement to compare radiation damage a) Yes b) No c) Don t know a) Equivalent dose b) Absorbed dose c) Don t know Table 2: The questionnaire given to the participants to assess the perception of knowledge in radiation biology 11. Do you prefer to take radiographs for an initial carious tooth? Yes No 12. Do you always advice patient s bystanders to wait outside the X ray room during radiographic procedure Yes No 13. If a pregnant patient (of 5 months) report for an IOPAR, will you send her back? Yes No 14. Do you prefer to use lead apron and thyroid collar for pregnant patients Yes No 15. Do you always wear a lead apron or stand behind a lead barrier during radiographic procedures? Yes No 16. Do you use a thyroid collar for your patient during radiographic procedures? Yes No 17. Do you always use a lowest possible setting for your radiographic procedures Yes No 18. Do you prefer F films than E films for your patients? Yes No 19. Do you prefer patients to hold IOPAR film in mouth than using a Snap a ray? Yes No 20. For a pediatric patient, will you prefer to hold IOPAR film by yourself than by the parents? Yes No 6 Journal of Medicine, Radiology, Pathology & Surgery Vol. 3:5 Sep-Oct 2016

3 Knowledge and perception toward radiation protection protocols Nagaraj, et al. Table 3: Comparison of knowledge in radiation biology and perception between PG students and interns (P<0.001) % of knowledge score n Mean±SD Minimum Maximum t P PG student ± <0.001 Interns ± Total ± % of practice score PG student ± <0.001 Interns ± Total ± p< very highly significant, SD: Standard diviation Figure 1: Comparison of knowledge and perception in radiation biology in PG students and interns This difference in the percentage was found to be statistically significant with a P < The majority of the participants correctly answered the question regarding the position distance rule (98% PG students, 84% interns), most sensitive site in the cell (86% PG students, 83% interns) and the mechanism by which X-rays cause cell death (95% PG students, 82% interns). However, only less number of participants were able to answer the questions like the cells most susceptible to radiation (79% PG students, 47% intern), the most radiosensitive cells in the oral cavity (67% PG students, 32% interns), the best type of collimators for radiation protection (69% PG students, 40% interns), and the action of X-rays on the optic lens if directed toward the eyes (36% PG students, 23% interns). Only 67% of PG students and 40% of interns correctly answered the question regarding the unit of measurement of radiation. Only 69% of PG students and 55% of interns correctly answered the question regarding the difference in exposure when film source distance is more. 89% of the PG students and 67% correctly answered the question regarding the difference in the radiation exposure between the digital machine and the conventional machine. Table 4: Percentage of correct responses to each question given by the PG students and interns Questions Answered Yes n (%) P PG Interns (100) Total (200) student (100) Q1 95 (95.0) 82 (82.0) 117 (88.5) Q2 79 (79.0) 47 (47.0) 126 (63.0) <0.001 Q3 86 (86.0) 83 (83.0) 169 (84.5) Q4 67 (67.0) 32 (32.0) 99 (49.5) <0.001 Q5 36 (36.0) 23 (23.0) 59 (29.5) Q6 98 (98.0) 84 (84.0) 182 (91.0) Q7 69 (69.0) 40 (40.0) 109 (54.5) <0.001 Q8 69 (69.0) 55 (55.0) 124 (62.0) Q9 89 (89.0) 67 (67.0) 156 (78.0) <0.001 Q10 67 (67.0) 40 (40.0) 107 (53.5) <0.001 Q11 96 (96.0) 95 (95.0) 191 (95.5) Q12 94 (94.0) 80 (80.0) 174 (87.0) Q13 89 (89.0) 59 (59.0) 148 (74.0) <0.001 Q14 93 (93.0) 86 (86.0) 179 (89.5) Q15 83 (83.0) 69 (69.0) 152 (76.0) 0.02 Q16 58 (58.0) 38 (38.0) 96 (48.0) Q17 80 (80.0) 60 (60.0) 140 (70.0) Q18 71 (71.0) 55 (55.0) 126 (63.0) Q19 64 (64.0) 57 (57.0) 121 (60.5) Q20 72 (72.0) 56 (56.0) 128 (64.0) p< significant, p< highly significant, p< very highly significant Knowledge regarding the radiation protection is not sufficient; applying this knowledge to practice is very important. 10 questions were given to assess the perception, i.e., to assess whether they are applying the knowledge to themselves; their patients, as well as the public, is protected from radiation. More than 95% of the participants do not prefer radiographs for initial carious teeth. 94% of PG students and 80% of interns always made sure that the patient bystanders are away from the radiology room during radiographic procedures. This difference was found to be statistically significant with P < The majority of the participants used protective measures like lead apron and lead barrier and prefer F films for their patients, but only very less participants used thyroid collar for their patients. In this study, only 58% of PG students and 38% of interns used thyroid collars for their patients. <70% of the participants used snap-a-ray for placement of the film. 64% of PG students and 57% of interns preferred their patients to hold the film. 38% of the PG students and 44% of the interns preferred to hold the radiographic film by their own if their pediatric patient is un-cooperative. All these practices may increase radiation exposure. Knowledge regarding the most radiosensitive cells in oral cavity, best collimators, the Journal of Medicine, Radiology, Pathology & Surgery Vol. 3:5 Sep-Oct

4 Nagaraj, et al. Knowledge and perception toward radiation protection protocols difference in the exposure with orthopantomograph and intraoral periapical radiograph (IOPAR), and the unit of measurement of radiation damage was found to be high among the PG students than interns and the difference in the response was found to be statistically highly significant (P < 0.001). This questionnairebased study showed that the knowledge of radiation biology and perception of this knowledge in clinical practice was high in PG students compared to interns and the difference is statistically highly significant with P < Discussion X-rays causes cell death by ionization. [1] Ionizing radiation is the subject of considerable safety legislation designed to minimize the risks to radiation workers and to patients. The International Commission on radiological Protection (ICRP) regularly publishes data and general recommendations based on the following general principles: 1. No practise should be undertaken unless its introduction gives a positive benefit (Justification). 2. Always the exposures should be kept as low as reasonably practicable, taking economic and social factors into account (optimization). 3. The maximum dose to the individuals should not exceed the limits suggested by ICRP (limitation). [7] A dentist should be knowledgeable on radiation biology and radiation protection measures so as to make sure that these guidelines are followed. This short study was conducted with a self-designed questionnaire to assess the level of awareness on radiation biology and to assess how well the participants were using this knowledge to practice dental radiography. A subtle variation was noted in regard to the knowledge and understanding of the basic biology of radiation between interns and PG students. This contrasting aspect was mainly noticed in answering questions regarding the radiosensitivity of cells. The more primitive the cells, the more will be the susceptibility to radiation. Casarett has divided mammalian cells into five categories of radiosensitivity on the basis of histologic observation of early cell death. [1,2] This includes vegetative intermitotic cells, differentiating intermitotic cells, multipotent connective tissue cells, reverting post-mitotic cells, and fixed post-mitotic cells. Evaluation of the results of this study showed that majority of the participants were not aware of this category of the cells based on radio-sensitivity. This knowledge was very less among interns compared to that of PG students. The majority of the participants of this study correctly knew the position distance rule. Position distance rule states that if no barriers are available, then operator should stand at a minimum distance of six feet away from the patient at an angle of with respect to the direction of central ray. This rule takes advantage of inverse square law to reduce the intensity and also considers that in this position the patient s head will absorb most of the scattered radiation. [1,2] Collimation helps to reduce the size of the radiation beam thereby allowing only the useful beam to emerge; useful beam is defined as the part of the primary radiation which is allowed to emerge through the collimating device. The beam produced by the circular collimators are larger than the size of 2 intraoral film, whereas that by a rectangular collimator is slightly larger than the size of two intraoral film. [8] Majority of the participants of this study, both PG students and interns are not aware of the best type of collimators. This may be because of their poor clinical experience. The majority of the participants wrongly answered the question regarding the film source distance. As source film distance is increased collimation must be correspondingly increased to reduce the beam size, thereby reducing the volume of tissue irradiated thus reducing the patient dose. [1,2] Panoramic radiography is a radiographic procedure that produces a single tomographic image of both jaws and their supporting and surrounding structures. There is greater ease and less time taken to produce a panoramic radiograph compared to full mouth IOPAR and additional advantage is that there is visualization of areas of the body of mandible, ramus, temporomandibular joint, and maxillary sinus. One of the greatest advantages of panoramic radiography is that the patient dose is relatively less. [9] This study showed that interns were not aware of this fact. This may be because interns, even though they are studying about the extraoral radiographs and the machine they are not practicing extraoral radiographs in the colleges. Equivalent dose is the unit of measurement to compare the biologic effects of different type of radiation to a tissue or organ. It also helps to facilitate comparison between biological effects of exposure and various types of radiation. [10] Only less number of PG students and interns who participated in this study are aware of the units used for measuring the radiation damage to tissues. Even though the knowledge of all the participants was less, their practice was found to be better. Dentists should exercise professional judgment when prescribing diagnostic radiographs for dental patients. [1] This means diagnostic radiography should be used only if necessary, after thorough history taking and clinical examination, and considering both the dental and the general health needs of the patient. More than 95% of the participants in the present study avoid taking radiographs for an initial carious tooth which showed that they are exercising professional judgment. The surrounding environment should be protected from the radiation to avoided exposure to general public. Primary beam should never be directed at anyone other than the patient. The majority of the participants in this study followed this as they advise the bystanders of their patients to stay away from radiology room. Interns participated in the study preferred to send back pregnant patients if reported in their second trimester without doing the radiographic procedure. This may be due to the lack of knowledge that the organogenesis of the embryo is taking place during the first trimester and pregnant patients can be exposed to radiation during the second trimester if needed, with proper protective measures. [9,11] Interns also lack the knowledge regarding the significance of thyroid collars. The exposure reduction of thyroid collars ranges from 5-56% for a complete mouth survey. [12] The exposing dentists should be familiar with the appropriate settings to use and should use lowest possible settings if possible while maintaining the quality of the image. Unfortunately, most of the interns 8 Journal of Medicine, Radiology, Pathology & Surgery Vol. 3:5 Sep-Oct 2016

5 Knowledge and perception toward radiation protection protocols Nagaraj, et al. participated in this study were not aware about the effect of high settings on biological tissues. Radiation exposure can be reduced if F- films are used as they are very sensitive to radiation. [9,13] The participants in this study preferred to use F-films to reduce exposure. IOPAR film should be never held by the operator or the patient to avoid radiation exposure. Ideally, film holding devices should be used. Film holding devices reduce frequency of retakes due to improper alignment and also reduces exposure to fingers. In case correct retention is not possible then a parent or any other individual responsible for the patient must hold the film in position. [1] Most of the interns and some of the PG students in this study preferred their patient to hold the film instead of using film holding devices and some of them preferred to hold the films by themselves for un-cooperative pediatric patient. This contrasting aspect can be attributed to less clinical experience of the interns. [1,14] The previous studies have shown that there was poor knowledge in radiation biology among both dental and medical students. [14-16] Some studies have shown poor knowledge in radiation biology among the practitioners; both dental and medical. [17,18] as well as in radiographers [19] and other health workers. [20,21] Obtained results from this study also showed a similar result. The knowledge and perception level regarding the radiation protection are less in PGs and interns but compared to interns PGs scored well. Conclusion This study showed that the knowledge in radiation biology and perception of this knowledge to practice was higher with PG students than in the interns. Despite their poor knowledge in radiation biology, their practice was better. This showed that they are blindly following certain protocols without knowing the exact reason for this. Hence, they should try to gain more knowledge so that more appropriate radiation protection practices and guidelines are followed. This helps in protection of the patients, operator and public from the harmful effects of radiation. Clinical significance Similar studies in radiation protection can be carried out at regular intervals at institutional and national level for strict adherence of radiation protection protocols. References 1. White SC, Pharoah MJ. Radiation Biology in Oral Radiology Principles and Interpretation. 5 th ed., Ch. 2. St. Louis: Mosby; p Karjodkar F. Textbook of Dental and Maxillofacial Radiology. 2 nd ed. India: Jaypee Brothers Medical Publishers (P) Ltd.; Linet MS, Slovis TL, Miller DL, Kleinerman R, Lee C, Rajaraman P, et al. Cancer risks associated with external radiation from diagnostic imaging procedures. CA Cancer J Clin 2012;62: White SC, Mallya SM. Update on the biological effects of ionizing radiation, relative dose factors and radiation hygiene. 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A study of knowledge and awareness of medical doctors towards radiation exposure risk at Tikur Anbessa. Specialized Referral and Teaching Hospital. Addis Ababa, Ethiopia. J Pharm Biol Sci 2012;2: Mojiri M, Moghimbeigi A. Awareness and attitude of radiographers towards radiation protection. J Paramed Sci 2011;2: Smith NJ. Continuing education in radiation protection: Assessment of a one-day course. Br Dent J 1991;170: How to cite this article: Nagaraj T, Sreelakshmi N, James L, Veerabasaviah BT, Goswami RD, Balraj L. An assessment of knowledge and perception of postgraduate students and interns toward radiation protection protocols: A questionnaire-based study in dental colleges. J Med Radiol Pathol Surg 2016;3:5-9. Journal of Medicine, Radiology, Pathology & Surgery Vol. 3:5 Sep-Oct