Comprehensive assessment of radiation dose in patients undergoing percutaneous coronary intervention: the effect of beam angulation on patient dose optimization

Background: Interventional cardiology (IC) procedures such as percutaneous coronary intervention (PCI) could generate a high radiation dose to both patients and medical staff. In this study, a comprehensive analysis was performed on patient dose during PCI procedures and evaluating the effect beam angulation on dose-area product (DAP) rate in cardiac catheterization laboratory. Materials and Methods: We studied 30 PCI procedures in angiography department during four months. A calibrated DAP meter was used to record patients’ dosimetric characteristics. Effective dose (ED) was calculated using DAP values along with DAP to ED conversion factor. Local diagnostic reference levels (DRLs) of the DAP, fluoroscopy time, and number of CINE frames were calculated as third quartile values of these parameters. Results: The mean ± SD of DAP value per procedure was 31.4 ± 17.1 Gy.cm², while corresponding values for fluoroscopy and CINE-acquisition (CINE) were 17.1 ± 11.2 Gy.cm² and 14.4 ± 8.2 Gy.cm², respectively. The estimated mean value of effective dose per procedure was 5.7 ± 3.1 mSv. The projection 40º LAO/ 30º caudal had the highest DAP rate value during CINE across various projections. Local DRLs were proposed as follows: 39.6 Gy.cm², 6.9 min, and 679 frames. Conclusion: The mean values of DAP in this study were lower than in previous published literature. Further, deep tube angulation led to increase DAP rates. It is recommended to use minimum tube angulation for avoiding unnecessary radiation exposure.