Strategy to Reduce the Collective Equivalent Dose for the Lens of the Physician’s Eye Using Short Radiation Protection Curtains to Prevent Cataracts

Koichi Nakagami,Tomoko Kuriyama,Takashi Moritake,Koichi Morota,Satoru Matsuzaki,Keisuke Nagamoto,Naoki Kunugita

doi:10.3390/diagnostics11081415

Abstract

A short curtain that improves on the low versatility of existing long curtains was developed as a dedicated radiation protective device for the over-table tube fluorographic imaging units. The effect of this short curtain in preventing cataracts was then examined. First, the physician lens dose reduction rate was obtained at the position of the lens. Next, the reduction rate in the collective equivalent dose for the lens of the physician’s eye was estimated. The results showed that lens dose reduction rates with the long curtain and the short curtain were 88.9% (literature-based value) and 17.6%, respectively, higher with the long curtain. In our hospital, the reduction rate in the collective equivalent dose for the lens of the physician’s eye was 9.8% and 17.6% with a procedures mixture, using the long curtain where technically possible and no curtain in all other procedures, and the short curtain in all procedures, respectively, higher with the short curtain. Moreover, a best available for curtains raised the reduction rate in the collective equivalent dose for the lens of the physician’s eye a maximum of 25.5%. By introducing the short curtain, it can be expected to have an effect in preventing cataracts in medical staff.

Highlights

The International Commission on Radiation Protection (ICRP), in its 2011 “ICRP Statement on Tissue Reactions,” recommended “an equivalent dose limit for the lens of the eye of 20 mSv year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv” [1]
The lens dose reduction rate was much higher with the long curtain than with the short curtain (Total DRRLong: 0.889, Total DRRShort: 0.176), viewed from the perspective of collective equivalent dose for the lens of the physician’s eye, the reduction rate was calculated to be lower for a procedures mixture, using the long curtain where technically possible and no curtain in all other procedures (Collective HLens RRLong: 0.098) versus using the short curtain in all procedures (Collective HLens RRShort: 0.176) (Table 2)
Even though the dose reduction rate is low with short curtains alone, the results suggest that, when they are widely used, the reduction in the collective equivalent dose for the lens of the physician’s eye is superior to that with long curtains

Summary

Introduction

The International Commission on Radiation Protection (ICRP), in its 2011 “ICRP Statement on Tissue Reactions,” recommended “an equivalent dose limit for the lens of the eye of 20 mSv year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv” [1]. The equivalent dose for the lens of the eye of medical personnel who perform endoscopic retrograde cholangiopancreatography (ERCP) is reported to be 15.5–210 μSv per patient [3,4,5,6,7,8]. It has been reported that, when gastroenterologists perform ERCP without any lens protection, the equivalent dose limit for the lens of the eye (20 mSv/year) is exceeded [9,10]. The International Atomic Energy Agency (IAEA) has released information showing that exposure can be reduced with the use of lead glasses, ceiling-suspended lead acrylic shields, or movable shields, and teaches the importance of lens protection [12]. It would be difficult to conclude that physicians adopt sufficient lens protection [13]

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Results

Discussion

Conclusion