Optimizing radiation protection of the operator during cardiac catheterization by minimizing the effective dose

Radiation exposure dosimetry for the personnel is based on measurements of phantom studies. To determine effective dose values for different X-ray equipment, TLD-measurements were performed using an Alderson Phantom in the patient position and a second phantom in the typical position of the personnel. Various types of protective clothing as well as fixed shields were considered in the calculations. Additional thyroid protection collars reduce the effective dose by a factor of 1.8-2.6. In the sense of effective dose X-ray protective clothing with 0.35 mm lead equivalent and an additional thyroid protection collar provide a better protection against radiation than an apron with 0.5 mm lead equivalent without collar. The doses of the unshielded organs (thyroid, parts of the active bone marrow) contribute significantly to the effective dose of the staff. Therefore an additional shielding of these organs reduces the effective dose more than an increase of the lead equivalency of the existing apron. We recommend face shields and thyroid protection collars as a necessary part of anti-X protection for cardiac catherization laboratories.