Prospective analysis of intraoperative radiation dose in foot and ankle surgery using mini-C-arm fluoroscopy. Continuous series of 1064 procedures.

ABSTRACT

INTRODUCTION: Foot and ankle surgeons make daily use of mini-C-arm fluoroscopes. The present study aimed to quantify associated radiation doses. HYPOTHESIS: X-ray exposure for foot and ankle surgeons using a mini-C-arm fluoroscope is below the nuclear safety authority authorized doses of 20 mSv/year for the whole body and crystalline lens, 150 mSv/year for the thyroid and 500 mSv/year for the skin and limbs. MATERIAL AND METHODS: A single-center, single-surgeon prospective series was treated between February 2014 and December 2017. Doses emitted by the mini-C-arm (15cm field) were recorded during 1,064 operations. Doses received by the surgeon were recorded by 3 passive dosimeters (thorax, eyes and hands) and 1 active dosimeter. The significance threshold was set at p<0.05. RESULTS: A total of 64.4% of procedures concerned the forefoot, 35.3% the hindfoot and ankle, and 0.3% were strictly percutaneous. Mean dose-area product (DAP) per procedure was 3.9 cGy/cm2±7 in forefoot surgery, 1.1 cGy/cm2±0.9, and in hindfoot and ankle surgery 8.7 cGy/cm2±9.7 (p<0.05), for mean irradiation times of 7.6s±5.3 and 36.7s±35.5 respectively and image numbers 4.1±2.7 and 18.7±20.5. Total ankle replacement was associated with the highest doses 20.1 cGy/cm2±14.7. Mean daily active dosimetry was 2.2µSv±1.4. Mean annual dose to the hand, crystalline lens and deep (Hp(10)) and shallow (Hp(0.07)) whole body was respectively 1.28 mSv, 0.6 mSv, 0.31 mSv and 0.19 mSv. The highest annual exposure was recorded for the hands 2.68 mSv in 2015. There was a significant linear relationship between daily active dosimetry and daily emission daily active dosimetry=(DAP×0.11)+0.54, for a correlation coefficient of 0.77. DISCUSSION/CONCLUSION: The exposure of foot and ankle surgeons using mini-C-arms was well below threshold, and also lower than in the literature. LEVEL OF EVIDENCE IV.