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Introduction: Efforts should be made to minimize patient radiation exposure during extracorporeal shockwave lithotripsy (SWL).
Materials & Methods: Fluoroscopy time (FT) and radiation effective dose (Deff) were determined for 422 consecutive SWL. Standard imaging protocol was applied and adjusted based on clinical situation. Fluoroscopic imaging was done prior to; at 1,000 and 2,000 shocks; and at completion. Patient Deff was calculated using Monte Carlo simulation rendered by PCXMC software.
Results: 422 ESL (259 males; 163 females [79 of child bearing age]) were analyzed. Mean FT was 95.4 seconds (range 21-600); average Deff per patient was 0.847 mSv (range 0.116- 5.878). Digital exposures were not routinely done. FT based on stone size (<25mm2 = 94.1sec; 25-75 mm2 = 95.7 sec; >75 mm2 = 95.9 sec) was not significant. Estimated average Deff for patients was 0.784 mSv (<25mm2); 0.863 mSv (25-75 mm2); and 0.882 mSv (>75 mm2), respectively. No significant difference was noted regarding stone location [(ureteral 0.940 mSv); (renal 0.770 mSv)]. FT for females under age 49 was 94.2 +/-5.9 sec and mean Deff was 0.785 mSv (range 0.165-4.325). Deviation from the imaging protocol occurred in 36 ESL treatments (8.5%) with mean FT of 258.3 +/- 16.0 sec (range 185-600) and mean Deff of 2.336 mSv.
Conclusions: Radiation exposure during SWL is comparable to that of a conventional radiograph of the abdomen (KUB) at 0.7 mSv. Implementation of a standard imaging protocol during SWL Results in a reliable means to minimize radiation exposure to the patient.