Background: Ionising radiation carries an oncogenic risk which is linearly related to the dose. An estimation of the effective dose can be obtained from the measurements of the dose-area product (DAP), which is a measure of stochastic risk and a potential quality indicator.
Aim: To assess radiation exposure of patients in a large volume cardiac cath-lab.
Methods: A retrospective analysis of adult cardiac and peripheral percutaneous procedures (April to December 2004) was carried out to determine the DAP and estimated risk of malignancy. We identified 6 groups: Group 1 (n=100, coronary angiography and ventriculography); Group 2 (n=50, carotid stenting); Group 3 (n=50, aortography+coronary angiography+ventriculography); Group 4 (n=100, inferior extremities angiography+predilatation and stenting); Group 5 (n=100, coronary angiography+ventriculography+direct coronary stenting); Group 6 (n=100, coronary angiography+ventriculography+coronary predilation and stenting). Dose-area product meter attached on the X-ray unit was used for the estimation of the radiation dose received by the patient during the procedures.
Results: DAP values (mean+/-S.D.) ranged from 41+/-30 Gy cm2 in Group 1 (lowest) to 118+/-89 Gy cm2 in Group 6 (highest). Within each group, individual radiation exposure varies substantially: from 11 to 200 Gy cm2 in Group 1, and from 30 to 733 Gy cm2 in Group 6 patients. Average exposure in a Group 6 patient corresponds to a risk of mortality from a malignancy of about 1 in 1000.
Conclusion: The radiation dose varies substantially across different types of procedures and up to tenfold within the same procedure. The enhanced knowledge of radiation dose might help the cardiologist to implement radiation sparing procedures eventually minimizing patient and operator radiation hazards in invasive cardiology.