Speaker
Description
Introduction: Monitoring radiation dose distribution is essential for patient safety during fluoroscopically guided interventions. While Air Kerma (AK) is the standard machine reported metric for X-ray intensity, it does not fully characterize the actual dose absorbed at varying tissue depths. This study evaluates the correlation between AK and patient-specific dose equivalents, Hp(0.07) for skin exposure and Hp(10) for body absorption. By comparing these values, we aim to assess the reliability of machine-reported data in predicting depth-specific radiation burdens across various configurations.
Materials and Methods: Radiation dose data were collected from a fluoroscopy system across seven clinical projections, incorporating varied angulations and Focus Distances (FD) ranging from 15 cm to 25 cm. For each projection, AK was recorded directly from the system’s dosimetry software. Simultaneously, TLDs were utilized to measure the absorbed dose equivalents, Hp(10) and Hp(0.07).
Results: Data analysis revealed that the Caudal 35° (CAU35) projection generated the highest overall radiation dose, with high values recorded in Frontal AK, Hp(10) ,and Hp(0.07). In contrast, the CAU 20° + LAO 65° configuration resulted in the highest dose in the Lateral AK view. Furthermore, a direct correlation was observed between FD and radiation output, as the FD was increased from 15 cm to 25 cm, there was a consistent and significant increase across all measured dose parameters.
Conclusions: The study demonstrates that projection angulation and focus distance are primary drivers of both machine-reported and tissue-absorbed radiation doses. CAU35 represents the highest risk for frontal exposure, while steeper oblique views like CAU 20° + LAO 65° maximize lateral tube output. The dose escalation observed with increased FD highlights the clinical importance of positioning the image intensifier as close to the patient as possible to minimize the radiation dose.