Determinants of radiation dose during right transradial access. insights from the RAD-MATRIX study

Background The RAD-MATRIX trial reported a large operator radiation exposure variability in right radial percutaneous coronary procedures. The reasons of these differences are not well understood. Our aim was to appraise the determinants of operator radiation exposure during coronary right transradial procedures. Methods Patient arrangement during transradial intervention was investigated across operators involved in the RAD-MATRIX trial. Operator radiation exposure was analyzed according to the position of the patient right arm (close or far from the body) and in relation to the size of the upper leaded glass. Results Among the 14 operators who agreed to participate, there was a greater than 10-fold difference in radiation dose at thorax level (from 21.5 to 267 μSv) that persisted after normalization by dose-area product (from 0.35 to 3.5 μSv/Gy*cm2). Among the operators who positioned the instrumented right arm far from the body (110.4 μSv, interquartile range 71.5-146.5 μSv), thorax dose was greater than that in those who placed the instrumented arm close to the right leg (46.1 μSv, 31.3-56.8 μSv, P =.02). This difference persisted after normalization by dose-area product (P =.028). The use of a smaller full glass shield was also associated with a higher radiation exposure compared with a larger composite shield (147.5 and 60 μSv, respectively, P =.016). Conclusions In the context of the biggest radiation study conducted in patients undergoing transradial catheterization, the instrumented right arm arrangement close to the leg and greater upper leaded shield dimensions were associated with a lower operator radiation exposure. Our findings emphasize the importance of implementing simple preventive measures to mitigate the extra risks of radiation exposure with right radial as compared with femoral access.