Radiation awareness program for extracorporeal shockwave lithotripsy using Medstone lithotripters.

Abstract

To determine the effectiveness of a radiation awareness program in reducing the radiation exposure to patients treated by a Medstone lithotripter, the exposure was calculated at the end of each extracorporeal shockwave (SWL) treatment using a table of measurements of the estimated entrance exposure rates 70 cm from the X-ray tube port. The results, related to stone size and patient weight, were distributed every month to each radiologic technologist, and a summary was sent regularly to the treating urologists. The doses before and after the introduction of the radiation awareness program were compared to determine the effectiveness of the program, and the chi-square test was used to determine statistical significance. The average calculated radiation exposure before and after introduction of the radiation awareness program was 16.39 rad and 8.26 rad, respectively, for patients with single renal stones; 17.31 rad and 9.02 rad, respectively, with single ureteral stones; 18.45 rad and 9.39 rad, respectively, with multiple renal stones; and 20.59 rad and 11.28 rad, respectively with multiple ureteral stones. These reductions in calculated radiation exposure were statistically significant only with multiple ureteral stones (P = 0.03). The only statistically significant differences in the stone-free rates, retreatment rates, and post-SWL secondary procedure rates before and after the introduction of the radiation awareness program were seen in the stone-free rates with single renal stones: 70% v 65%, respectively (P = 0.02); in the retreatment rates with single ureteral stones: 10% v 6%, respectively ( P < .01); and in the post-SWL secondary procedure rates with single renal stones: 4% v 2%, respectively (P = 0.01), and single ureteral stones: 7% v 4%, respectively (P = 0.05). The radiation awareness program resulted in a 51% reduction in the estimated radiation exposure to patients during SWL using Medstone lithotripters.