Radiation Protection for Cardiac Cetheterization Laboratories Undergoing Intracoronary Brachytherapy

For gamma emitting sources, but also for beta emitting sources, where the whole body doses for the intervention staff (radiation oncologist, intervetionist, physicist) involved in coronary endovascular brachytherapy is even significantly lower, detailed knowledge of the magnitude of the whole body dose and also the extremities dose is needed in order to limit the dose to the staff members according to the ALARA principle. The dose rate distribution in the standard cardiac catheterization laboratory was calculated and in order to optain the dose to individuals of the intervention staff, but also to the population, the dose rate was multiplied by the treatment time, for each relevant location in- and outside of the cardiac catheterization laboratory. The doses to the different individuals were estimated by applying the inverse square law and taking into account the shielding factors by the human body and other relevant factors. Additionally area monitoring inside and outside the cardiac catheterization laboratory was done using suitable dosimeters and survey meters. Also a simple formula was invented which allows the intervention staff to work in the cardiac catheterization laboratory without additional lead shielding (sarcophagus) of the patients. The doses measured for the intervention staff is less than 7,5 µSv per treatment which is a dose less than 0,1% of the annual radiation workers Maximum Permissible Dose (MPD) recommended in the EC regulations. The measured dose for a single individual of the general public outside of the cardiac catheterization laboratory is less than 0,1 %o of the genral publics MPD recommended in the EC regulations. The personal dose measurements and calculations showed that all principles of ALARA are fulfilled within the clinical trials. Safety, effectiveness and optimisation and justification is also demonstrated.