Operator Exposure to Scatter Radiation from a Portable Hand‐held Dental Radiation Emitting Device (Aribex™ NOMAD™) While Making 915 Intraoral Dental Radiographs*

Abstract

Operator exposure to backscatter radiation while using an Aribex NOMAD radiation emitting device (a portable, self-contained, cordless, hand-held dental X-ray unit) was determined while the operator employed various typical and atypical use scenarios during the exposure of 715 digital and/or film-based dental radiographs and 200 study control exposures. Study data was compared to the radiation safety occupational exposure annual Maximum Permissive Dose (MPD) of 50 mSv (5000 mrem) to determine the possible exposure risk to an unprotected operator using this device. The results showed the reproductive organs received the highest dose and the thyroid the least. The average operator whole body dose for the study was determined to be 0.047 mSv (4.47 mrem) or 0.09% of the annual MPD. Extrapolating the data as an expression of averaged annual operator exposure resulted in a whole body dose of 0.4536 mSv (45.36 mrem) or 0.9% of the annual MPD, These results are well below established occupation exposure limits and are compatible with those published by the manufacturer.

The effects of device position on the operator's radiation dose when using a handheld portable X-ray device

“…However, most of the studies were performed in the USA 1,2,4,[7][8][9][10][11][12][13][14] with only a few studies in other countries, for example, Italy, 5 Belgium 3,15 and Korea. 16 To date, there are no reports from the UK although the device is available in the country.…”

“…3,[7][8][9][10][11] However, the distance away from the body is variable, dependent on the position of the hands and how the portable X-ray device is held by the operator. In addition, the only integral protection for the operator is a backscatter shield.…”

“…In this study, the maximum radiation dose recorded was for the left palm when the device was held perpendicular to the ground with the arms extended. Another study looked into this issue was by Danforth et al 7 in which the exposure to operator in typical (when the operator is in an upright position imaging a patient who is seated) and atypical positions (when the operator was in an upright position imaging a patient in the supine position) were investigated; they found that the reproductive organs received the highest dose, whereas the thyroid glands received the lowest dose. The study also found that the operator's backscatter exposure was ,1% of annual occupational MPD, and it was dependent on the operator position.…”

“…The study also found that the operator's backscatter exposure was ,1% of annual occupational MPD, and it was dependent on the operator position. 7 The operator exposure whole-body dose was 0.0453 mSv per year, which is equivalent to 0.9% of the annual MPD. The highest exposure recorded was to the reproductive organs, 0.095 mSv per year (0.19% of MPD).…”

“…The highest exposure recorded was to the reproductive organs, 0.095 mSv per year (0.19% of MPD). 7 A number of previous studies had shown the importance of the backscatter shield and significant reduction in the operator dose when the backscatter shield was used. McGiff et al 8 compared the operator's dose, with and without the presence of the backscatter shield; the radiation dose to the operator's head/torso/extremities with the backscatter shield was ,0.6 mSv per year, Device position effect on operator's dose in handheld X-ray devices whereas without the backscatter shield, it was 2 mSv per year.…”