Skin dose color mapping system in interventional radiology and cardiology

Abstract

The interventional radiology is among the fast-developing medical imaging modalities. There is an increase in the number of performed interventional procedures and the radiation-induced skin reactions became a concern. The type and degree of skin reaction depends of the absorbed skin dose. The National Cancer Institute (NCI) has established a skin reaction grading system, which classifies them according to the severity of the skin reaction, ranging from 1 to 4, with 1st grade being the least severe and 4th the most severe. The purpose is to (1) present the benefits and the limitations of available dose monitoring quantities to predict the skin reactions and to measure the peak skin dose (PSD), in terms of kerma area product (KAP), cumulative dose (CD) and fluoroscopy time (FT); (2) to survey the cumulative dose distribution of different interventional cardiology procedures in Bulgaria, and (3) to present a methodology for real time skin dose color mapping system during interventional procedures. The review of the available literature shows that there is poor correlation between FT and the other dose metrics. A substantial correlation between KAP or CD and PSD is reported. The better real-time dose indicator for skin reactions is KAP or CD. CD typically overestimates PSD and provides a conservative clinical skin-dose management tool. Real-time PSD measurement is the preferred methodology. Data for more than 500 interventional cardiology procedures was collected from three hospitals in Bulgaria and the CD values distribution was surveyed. The results show that 72% of the CD values are lower than 2 Gy; 12.5% are within the range (2–5) Gy; 3.8%: (5–10) Gy; 0.9%: (10–15) Gy and for 0.2%: CD >15 Gy. The dose ranges were selected in agreement with the NCI skin reaction grading system. Although the percentage of patients with CD values exceeding 5 Gy is not high, all kind of efforts to support medical staff avoiding such dose levels should be launched. A color mapping system, following the NCI Skin reaction grading system, will be useful tool for easy and fast orientation of the medical staff, according to the expected degree of complexity of the skin reactions.