Correlation of patient skin doses in cardiac interventional radiology withdose-area product

The use of X-rays in cardiac interventional radiology has the potential to induce deterministic radiation effects on the patient's skin. Guidelines pu blished by official organizations encourage the recording of information to evaluate this risk, and the use of reference values in terms of the: dose- area product (DAP). Skin dose measurements were made with thermoluminescent dosemeters placed at eight different locations on the body. In addition, D AP was recorded in 100 patients for four types of interventional radiology procedures. Mean, median and third quartile for these results are presented . Maximum skin dose values found were 412 mGy, 725 mGy, 760 mGy and 1800 mG y for coronary catheterization, coronary catheterization with left ventricl e investigation, and percutaneous transluminal angiography without and with stenting, respectively. Median DAPs for these same procedures were, respec tively, 5682 cGy cm(2) 10 632 cGy cm(2), 10 880 cGy cm(2) and 13 161 cGy cm (2) The relationship between DAP and skin dose was investigated. We found a poor correlation of DAP with maximum skin dose (r=0.77) and skin dose indi cator (r=0.78). Using conversion factors derived from Monte Carlo simulatio ns, skin dose distributions were calculated based on the measured DAPs. Agr eement between the calculated skin dose distribution, using DAP values aver aged over a group of patients who underwent coronary catheterization and le ft ventricle investigation, and the measured skin dose averaged over the sa me group of patients was very good. However, there were large differences b etween the calculated skin doses using the individual DAP data per patient and measured skin doses for individual patients. (r=0.66). Hence, calculati on of individual skin doses based on the specific DAP data per patient is n ot reliable and therefore measuring skin dose is preferable.