Purpose: Patient skin injury due to radiation exposure during interventional fluoroscopy procedures is a concern. The FDA has recommended dose be monitored, along with the dose distribution on the patient's skin. Modern fluoroscopy equipment provides a readout of the accumulated reference point air kerma. However, this parameter is a poor estimate of localized skin dose since it does not take into account beam movement. Acquisition information needed to calculate skin dose can be recorded as a DICOM Dose Structured Report (Dose SR), which has recently become available on new fluoroscopy equipment. We have developed a system that uses the Dose SR to produce a skin dose map, along with determination of the peak skin dose. Method and Materials: The Dose SR provides data for each irradiation event (fluoroscopy footswitch or acquisition): kerma‐area‐product, reference point air kerma, C‐arm angulation and table position. Using the position of the patient on the table, backscatter and table attenuation, the air kerma to 1‐cm2 regions on the patient's surface is calculated. The patient surface is approximated as a mathematical model using SolidWorks simulation software, with model size varied based on patient parameters. Results: The method was validated using a Siemens Axiom Artis angiography system. Measurements made with an ionization chamber and lucite phantom were compared to calculated skin dose values for a range of C‐arm angles, table positions and exposure levels. Errors ranged from 2–10% with higher errors corresponding to increased C‐arm angulation. Conclusion: A system has been developed to estimate skin dose and generate skin dose maps from an interventional procedure Dose SR. The system allows for a more precise determination of localized skin dose and assists with planning appropriate entry ports for future procedures to minimize skin injury. Application to any vendor platform providing a Dose SR is possible.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging