Systematic review on physician's knowledge about radiation doses and radiation risks of computed tomography

Abstract

Background

The frequent use of computed tomography is a major cause of the increasing medical radiation exposure of the general population. Consequently, dose reduction and radiation protection is a topic of scientific and public concern.

Aim

We evaluated the available literature on physicians’ knowledge regarding radiation dosages and risks due to computed tomography.

Methods

A systematic review in accordance with the Cochrane and PRISMA statements was performed using eight databases. 3091 references were found. Only primary studies assessing physicians’ knowledge about computed tomography were included.

Results

14 relevant articles were identified, all focussing on dose estimations for CT. Overall, the surveys showed moderate to low knowledge among physicians concerning radiation doses and the involved health risks. However, the surveys varied considerably in conduct and quality. For some countries, more than one survey was available. There was no general trend in knowledge in any country except a slight improvement of knowledge on health risks and radiation doses in two consecutive local German surveys.

Conclusions

Knowledge gaps concerning radiation doses and associated health risks among physicians are evident from published research. However, knowledge on radiation doses cannot be interpreted as reliable indicator for good medical practice.

Introduction

Computed tomography (CT) scanners are highly valuable and sometimes life-saving tools of modern diagnostic radiology. They provide detailed information quickly—an advantage in comparison to magnetic resonance imaging, particularly in emergency or perinatal and paediatric diagnostic. However, the benefit of CT is opposed by relatively high radiation exposures to the patient [1], [2]. Ionizing radiation is a known carcinogen, and cancer risks depend on factors such as the type of radiation, exposure time, irradiated tissue and age [3], [4]. Children have a higher risk per unit dose because their growing tissue is more susceptible to ionisation, and they have a longer life span to develop malignancies. Brenner et al. [5] estimated for the year 2000 that from the 600,000 abdominal and head CT examinations in children under the age of 15 years in the USA, 500 fatal cancers attributable to computed tomographies will occur in these children during their lifetime.

The radiation exposure from medical procedures, particularly from CT examinations, has been a topic of recent public and scientific discussion [6], [7]. In some countries, including Germany, the absolute numbers of diagnostic procedures with ionising radiation (e.g. conventional X-ray examinations) has been declining [10]. On the other hand, the use of CT examinations has increased rapidly. Due to the substantially greater doses of CT examinations compared to conventional X-rays, the medical radiation exposure per person has been increasing [10], [11]. Exposure can be reduced through dose reduction strategies (machine settings) or by lowering the number of prescribed computed tomographies [8], [9]. There is some evidence that radiologists generally adhere to published guidelines on dose reduction [12], [13]. However, physicians’ awareness of radiation risks and knowledge of suitable alternative examinations is a major requirement to reduce CT use in patients.

To further elucidate this topic, we conducted a literature-based study to elucidate knowledge on radiation risks associated with CT among physicians.