Fifty-seventh annual meeting of the American association of physicists in medicine
TH-AB-201-02: Fluoroscopy-Guided Radiation Dose; Best Correlated to Patient Thickness
To survey a radiation dose index of peripheral and trunk fluoroscopic interventional procedures at a tertiary care pediatric hospital. These results allow the correlation of a patient dose index to the patient thickness, age, weight, and body mass index (BMI) to be analyzed.
Radiation dose structured reports were retrospectively collected for pediatric and adult interventional fluoroscopic cases. Kerma Area Product (KAP), air Kerma (AK), fluoroscopy time (FT), thickness of body part irradiated, patient's age, height, and weight were collected. Cumulative AK was divided by fluoroscopy time to normalize the dose index by the complexity of the case. This index for each study was analyzed as a function of thickness of body part irradiated, patient age, weight, and BMI. Non-parametric correlation coefficients along with the 95% confidence intervals were computed to investigate which parameter correlates best with patient dose.
A total of 522 cases were included in the study. The patients’ irradiated body part thicknesses, ages, masses, and heights ranged from 1–35 cm, 0.01–61 years, 1.4–145.5 kg, and 37.5–190 cm respectively. The FT and AK of the cases ranged from 0.1–100 min and 0.1–2756 mGy respectively. The correlation with 95% confidence interval of AK/FT to each patient parameter is listed in the supporting document. Each patient parameter is statistically correlated with patient dose (p-value < 0.0001), however the correlation with patient thickness statistically provides the highest correlation whereas the three other parameters are of similar, lower correlation.
Fluoroscopy-guided patient dose indices should be reported as a function of patient thickness irradiated as opposed to the patient's age, weight, or BMI. If the thickness of the patient is unknown, our results suggest that any of the other three patient charateristics could be used.
K Strauss serves as a consultant to Philips Healthcare upon their request. R Nachabe is a paid employee of Phillips Healthcare.