Estimate of radiation dose to the lens in balloon sinuplasty
1Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA. RickChandra@hotmail.com
Objectives:
To estimate radiation dose to the lens during fluoroscopy-assisted balloon dilation of sinus ostia and to estimate the length of fluoroscopy time that will be tolerated.
Methods:
Radiation dose to the lens per unit fluoroscopy time was extrapolated from published data in fluoroscopically-guided balloon dacrocystoplasty.
Results:
Mean exposure varies from 0.041 (right eye) to 0.284 (left eye) mGy/sec (P = 0.037) because the left eye is closer to the radiation source during the lateral projection. Threshold for lenticular opacity has been estimated as 500 mGy, which would be attained in the left eye after approximately 29 minutes of fluoroscopy.
Conclusions:
The lens may tolerate <30 minutes of fluoroscopy during balloon sinuplasty. The left eye receives a potentially greater radiation dose because of its proximity to the source in the lateral projection. Dedicated studies are indicated to specifically examine this issue during balloon sinuplasty.
