CBCT Dose Reduction to Lens of Eye Using Leaded Glasses
Abstract
AD Goren, S Anikina, LT Dauer, B Quinn, K Kelly, A Chechelniker and I Branets
Objectives: The objective of this study was to measure the shielding effect of leaded glasses, tanning glasses with 1/16” Pb shielding and tanning glasses with lead foil in combination with thyroid collar compared with no shielding equipment to the lens of the eye to evaluate the percentage of dose reduction.
Methods: A CIRS female phantom head was used to measure the patient radiation dose to the organs of the head and neck from a Morita X800 CBCT using nano Dot optically stimulated luminescent dosimeters (OSL’S) placed at 23 head and neck sites. Leaded glasses, tanning glasses with 1/16” Pb shielding, tanning glasses with lead foil were placed over the phantoms eyes in conjunction with a thyroid collar. No Protective Equipment was used as a control. Radiation was performed using manufacturers predetermined exposure settings. All dosimeters were exposed three times. Radiation dose fractions to various organ sites were determined using reference values from ICRP-89. Organ equivalent doses were based on ICRP-103 tissue weighting factors.
Results: The per cent reduction to the lens of the eye for the leaded glasses compared to no Protective Equipment was 49.2%, 44.6% for the tanning glasses with 1/16” Pb shielding and 38.1% for the tanning glasses with lead foil. For all modes of eye wear the highest organ doses were seen in the salivary glands, extrathoracic airway, and the oral mucosa. The use of proper PPE is necessary to protect the eye from possible cataractogenesis.
Conclusions: Research on the correlation between cataract formation and ionizing radiation has shown that the dosage and frequency of exposure play a role in damaging the DNA in the lens of the eye. Here we demonstrate that regular leaded glasses and the tanning glasses with 1/16”Pb shielding are about equal in reducing the dose to the lens of the eye. One caviat, the size of the regular lead glasses might interfere with anatomical landmarks while tanning glasses would allow more diagnostic information. Further studies should be performed.