MEASUREMENT OF EYE LENS DOSE IN INTERVENTIONAL RADIOLOGIST FROM TACE PROCEDURES USING OSLD

Abstract

For routine clinical service at Section of Interventional Radiology, Department of Radiology, King Chulalongkorn Memorial Hospital (KCMH), TACE procedure has been one of the high exposure procedures, which result in increasing eye lens dose in interventional radiologists. Thus, radiation dose should be evaluated in interventional radiology staff who may receive high eye lens dose. Currently, there is insufficient information to comply with the ICRP dose limit on the occupation exposure to the eye lens. One of the factors affecting the eye lens dose is the variation in tube directions in the interventional radiology (IR) laboratories. A preliminary study about tube angulations influence radiation exposure to the eye lens has been conducted. The objectives of this study are to determine the average annual equivalent doses and the parameters influence equivalent doses to the eye lens of the interventional radiologists in TACE procedures at King Chulalongkorn Memorial Hospital. In order to determine the average annual eye lens dose of an interventional radiologist and three fellows, four nanoDot (OSL) dosimeters were taped on the left and right sides of the inside and outside of lead glass eyewear and measured monthly. The annual eye lens doses were then estimated. The influence of tube angulation to the eye lens dose had been studied using Toshiba digital flat-panel angiographic system (Infinix-I 8000C) and nanoDot dosimeters taped on the lead glass eyewear which applied to the rando phantom to simulate the interventional radiologist under TACE procedure. The results show the average annual eye lens dose measured from an interventional radiologist and three fellows at left side was 7.64 mSv and at the right side was 6.21 mSv when the lead glass eyewear was applied. The maximum estimated annual dose at the left and right eyes without lead glasses were 31.96 and 24.23 mSv respectively. Tube direction under LAO combined with caudal angle delivered the highest eye lens dose of 9.20 mSv/procedure at the left eye when protective equipment was not utilized. The eye lens dose at the right side inside the lead glass eyewear was higher than outside in two fellows as some scattered radiation can reach the right nanoDot inside lead glasses without reaching the outside dosimeter. Radiation exposure from LAO series was high due to the shorter distance between the source of scattered radiation and the phantom than the other tube directions. The annual eye lens dose of the interventional radiologist has the potential to exceed the new ICRP dose limit of 20 mSv/year if radiation protective tools are not properly used.