Program Information
Head and Neck Tissue Dose From X-Ray Scatter to Physicians Performing Cardiovascular Procedures
K Fetterly1*, B Schueler2 , M Grams3 , G Sturchio4 , (1) Mayo Clinic, Rochester, MN, (2) Mayo Clinic, Rochester, MN, (3) Mayo Clinic, Rochester, MN, (4) Mayo Clinic, Jacksonville, FL
Presentations
TU-D-209-6 (Tuesday, August 2, 2016) 11:00 AM - 12:15 PM Room: 209
Purpose:
The purpose of this work was to characterize the spatial distribution of scatter radiation to the head and neck of a physician performing an x-ray interventional procedure and assess brain, eye lens, and carotid artery dose.
Methods:
Radiographic x-ray beams were tuned to match the peak energy (56 to 106 keV) and HVL (3.5 to 6.5 mm Al) of x-ray scatter originating from a patient during a fluoroscopic procedure. The radiographic beam was directed upon a Rando phantom from an inferior-left location to mimic a typical patient-operator geometric relationship. A lead-equivalent protective garment was secured to the phantom. Direct exposure Gafchromic film (XRQA2) was placed between the transverse plane layers of the head and neck region of the phantom and exposed with 4 scatter-equivalent radiographic beams. A 3x3 cm² film placed at the left collar of the phantom was used to monitor incident dose in the position of a radiation monitoring badge. The films were converted to 2D dose distribution maps using FilmQA Pro software and an Epson 11000-XL scanner. The 2D dose distributions maps were normalized by the left collar dose and the percent of left collar dose (%LCD) was calculated for select tissues.
Results:
The dose maps had high dynamic range (10⁴) and spatial detail. Considering all transverse planes and 4 scatter beam qualities, the median %LCD values were: whole brain 8.5%, left brain 13%, right brain 5.4%, left eye lens 67%, right eye lens 25%, left carotid artery 72%, and right carotid artery 28%.
Conclusion:
Scatter radiation dose to an operator can be simulated using a tuned radiographic beam and used to expose a phantom and Gafchromic film, thereby creating detailed 2D dose distribution maps. This work facilitates individualized estimation of dose to select head and neck tissues based on an operator’s radiation monitoring badge value.
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