(Sunday, 7/12/2020) [Eastern Time (GMT-4)]
Room: AAPM ePoster Library
Purpose:
To establish empirical equations to estimate appropriate pediatric fluoroscopy dose alert levels that can be applied in any institution that knows its institution’s average adult sized patient and radiation air Kerma.
Methods:
Fluoroscopy dose data along with patient size (AP or LAT) was collected for examinations performed between October 2016 and March 2019 for general fluoroscopy (11,132 exams) and mobile-C-arms (6145 exams). The studies for general fluoroscopy were grouped into 4 categories, namely, tube placement (TP), gastrointestinal (GI, upper and lower), voiding cystourethrogram (VCUG) and Video Swallow Study (VSS). For mobile c-arms, the studies are grouped based on their mean dose levels into low, medium and high dose categories. The dose data was log-transformed and linear fits of the logarithmic dose as a function of patient size appropriate for the examination were calculated. 1% and 5% trigger levels were determined based on 98% and 90% prediction intervals of the linear fit and the fit parameters for the trigger levels are reported.
Results:
The equation for the 5% dose trigger level (D5) for each fluoroscopy study group can be defined as: D5 = exp(m*x+s5*y) where m is the slope value, x is the size of the patient (AP or LAT) in centimeters, s5 is the scalar constant for the 5% trigger level and y is the intercept value. An outside institution can determine its own intercept value y based on the equation: y=LN?(D_avg)-m*x_avg, where D_avg is the institution’s average dose (in µGy) and x_avg is the size of the average patient (in centimeters).
Conclusion:
An empirical equation to estimate fluoroscopy dose alert levels for pediatric patients based on patient size has been developed using dose and size data collected over a period of 3 years at a large academic pediatric institution.
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Taxonomy
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