Uterine artery embolization for leiomyomata: optimization of the radiation dose to the patient using a flat-panel...

The purpose of this study was to assess the ability of low-dose/low-frame fluoroscopy/angiography with a flat-panel detector angiographic suite to reduce the dose delivered to patients during uterine fibroid embolization (UFE). A two-step prospective dosimetric study was conducted, with a flat-panel detector angiography suite (Siemens Axiom Artis) integrating automatic exposure control (AEC), during 20 consecutive UFEs. Patient dosimetry was performed using calibrated thermoluminescent dosimeters placed on the lower posterior pelvis skin. The first step (10 patients; group A) consisted in UFE (bilateral embolization, calibrated microspheres) performed using the following parameters: standard fluoroscopy (15 pulses/s) and angiography (3 frames/s). The second step (next consecutive 10 patients; group B) used low-dose/low-frame fluoroscopy (7.5 pulses/s for catheterization and 3 pulses/s for embolization) and angiography (1 frame/s). We also recorded the total dose-area product (DAP) delivered to the patient and the fluoroscopy time as reported by the manufacturer's dosimetry report. The mean peak skin dose decreased from 2.4 +/- 1.3 to 0.4 +/- 0.3 Gy (P = 0.001) for groups A and B, respectively. The DAP values decreased from 43,113 +/- 27,207 microGy m(2) for group A to 9,515 +/- 4,520 microGy m(2) for group B (P = 0.003). The dose to ovaries and uterus decreased from 378 +/- 238 mGy (group A) to 83 +/- 41 mGy (group B) and from 388 +/- 246 mGy (group A) to 85 +/- 39 mGy (group B), respectively. Effective doses decreased from 112 +/- 71 mSv (group A) to 24 +/- 12 mSv (group B) (P = 0.003). In conclusion, the use of low-dose/low-frame fluoroscopy/angiography, based on a good understanding of the AEC system and also on the technique during uterine fibroid embolization, allows a significant decrease in the dose exposure to the patient.