Radiation exposure of radiation-sensitive risk organs--ocular lens, parotid gland, thyroid gland--in dacryocystography and therapy

Abstract

Evaluation of radiation dose to the radiosensitive head and neck organs and tissues-ocular lens, parotid and thyroid glands--during dacryocystography and fluoroscopy--guided dacryocystoplasty (DCP). Radiation dose was determined in an Alderson Rando phantom and in 13 patients. Radiation dose was measured directly using Ca-F2-thermoluminescent dosimetry crystals (TLD) which were placed on each eyelid, parotid gland and thyroid gland. The mean radiation dose to the lens placed next to the path of radiation was 6.58 mGy in the Alderson-Rando phantom and 5.43 mGy in patients during DCP. The mean radiation dose to the contralateral lens was 1.37 mGy and 1.7 mGy to the parotid gland placed next to the x-ray tube. Radiation dose to the thyroid gland was max. 0.4 mGy during DCP. Radiation dose to the ocular lens, parotid gland and thyroid gland during fluoroscopy-guided DCP was 25 times higher than during diagnostic dacryocystography. The radiation dose to radiosensitive head and neck organs and tissues during fluoroscopy-guided DCP is much below the threshold dose for ocular lens cataract.