Assessment of patient effective radiation dose and associated radiogenic risk from extracorporeal shock-wave lithotripsy.

The aim of the present study was to calculate patient effective dose and associated radiogenic risk from fluoroscopy guided extracorporeal shock-wave lithotripsy procedures. Fluoroscopy required during extracorporeal shock-wave lithotripsy was classified in two types identified by beam orientation: antero-posterior and 30 degrees anterior-oblique projected exposures. Duration of each exposure was monitored in 124 patients undergoing extracorporeal shock-wave lithotripsy treatment for ureteral stones. The dose from a kidney-ureter-bladder radiograph and the dose per min of fluoroscopy along antero-posterior and anterior-oblique projections were measured at 13 organs/tissues using an anthropomorphic phantom and thermoluminescence dosimetry. A radio-opaque object was placed in the phantom to simulate an ureteral stone at the proximal and distal ureter. The total effective dose in male and female patients with proximal ureteral stones was 1.71 mSv and 1.82 mSv, respectively. The corresponding values for male and female patients with distal ureteral stones was 0.76 mSv and 1.62 mSv, respectively. In the United States, the theoretical sex-averaged radiogenic excess of fatal cancers was estimated to be 140 per million and 85 per million of patients treated for proximal and distal ureteral stone, respectively. The average radiogenic risk for genetic defect associated to treatments of proximal and distal ureteral stones was found to be 2.5 and 24.4 per million of births, respectively. The radiation risk from a typical fluoroscopy guided extracorporeal shock-wave lithotripsy treatment of ureteral stones is low. Presented data may be used to determine patient effective dose from extracorporeal shock-wave lithotripsy procedures performed in any laboratory.