Impact of Low Dose Fluoroscopy in Ureteroscopy

One of the most effective strategies to decrease radiation exposure during ureteroscopy is to use low dose. However, the quality of the image obtained is inferior to full dose image. The main concern is to maintain the stone free and complication rate despite the inferior quality of image obtained. Our aim was to evaluate if reducing the dose of fluoroscopy to ¼ instead of full dose would impact in a reduction of total radiation exposure despite a possible increase in fluoroscopy time. Also, if this strategy would impact in operation time, stone free rate and complication rate of unilateral semi-rigid ureteroscopy for ureteral stone treatment due too less than optimal fluoroscopy image. All patients over 18 years old diagnosed with ureteral stone from 5 mm to 20 mm in diameter by CT scan were counseled regarding their treatment options. Patients who failed spontaneous passage or medical treatment or chose endourologic treatment were included in this study. Patients with abnormal urinary anatomy such as horseshoe kidney, pelvic kidney or duplex system were excluded from the study.

Several studies support an association between increasing cancer risk with increasing exposure to radiation. Typical radiation exposure for a patient submitted to ureteroscopy ranges from 2.5 to 100 mSv. The International Commission on Radiological Protection recommends an annual occupational radiation exposure limit of no more than 50 mSv per year. One of the most effective strategies to decrease radiation exposure during ureteroscopy is to use low dose. However, the quality of the image obtained is inferior to full dose image. The main concern is to maintain the stone free and complication rate despite the inferior quality of image obtained. Our aim was to evaluate if reducing the dose of fluoroscopy to ¼ instead of full dose would impact in a reduction of total radiation exposure despite a possible increase in fluoroscopy time. Also, if this strategy would impact in operation time, stone free rate and complication rate of unilateral semi-rigid ureteroscopy for ureteral stone treatment due too less than optimal fluoroscopy image. All patients over 18 years old diagnosed with ureteral stone from 5 mm to 20 mm in diameter by CT scan were counseled regarding their treatment options. Patients who failed spontaneous passage or medical treatment or chose endourologic treatment were included in this study. Patients with abnormal urinary anatomy such as horseshoe kidney, pelvic kidney or duplex system were excluded from the study.

Each group of patients (1/4 dose and full dose) will have assigned one dosimeter to assess the radiation exposure every procedure. The sum of radiation of each group will be compared at the completion of the study (2 years) , because individual radiation exposure is too low to be measured. Radiation exposure will be measured (data stored inside the dosimeter) by dosimeter in mSv units at each procedure and the total sum of radiation will be done at the end of the study (2 years).

Inclusion Criteria: ureteral stone from 5 mm to 20 mm in diameter by CT scan Exclusion Criteria: abnormal urinary anatomy such as horseshoe kidney, pelvic kidney or duplex system