The radiation dose to staff and patient from intraoperative O-ARM system in Percutaneous Transforaminal Lumbar Interbody Fusion (TLIF) surgery

Abstract

The O-Arm system has the capability of combined two-dimensional fluoroscopy and three-dimensional computed tomography for intraoperative procedure. The increasing use of this system raises the concern of radiation exposure to staff and patients. The purpose of this study is to estimate the radiation dose delivered to staff and patient during Percutaneous TLIF surgery in 2D and 3D modes when using o-arm system. The data from one hundred patients underwent percutaneous TLIF surgery in 2D and 3D modes using O-Arm system were recorded from PACS (Picture Archiving and Communication System) and calculated for the patient radiation dose. For staff radiation dose, the scattered dose around the O-Arm gantry were measured using CT phantom to represent patient and scan with the maximum exposure parameters. The results showed that the average patient age was 59 (25-91) years. In 2D; the average exposure time was 15.09 (5.63-42.57) sec. The effective dose was 1.3 (0.34-4.63) mSv. In 3D; the average exposure time was 10.05 (7.80-15.64) sec. The effective dose was 10.38 (4.32-27.02) mSv. The number of scan was 2 times (53 cases), 3 times (37 cases) and 4 times (10 cases). The average effective dose from 2, 3 and 4 times scan were 8.14 mSv, 11.72 mSv and 16.97 mSv, respectively. In 2D, small size protocol was not selected. Medium size protocol was selected for 95 cases and the average effective dose was 1.27 (0.34-4.63) mSv. Large size protocol was selected for 5 cases and the average effective dose was 1.92 (1.4-3.15) mSv. In 3D, the ST3D protocol, small size protocol was not selected, medium size was selected for 63 cases and the average effective dose was 8.15 (4.32-19.59) mSv. The large size protocol was 34 cases and the average effective dose was 13.65 (10.79-21.61) mSv. In 3D, the HD3D protocol, the large size protocol selected was 3 cases and the average effective dose was 20.26 (13.51-27.02) mSv. The radiological technologist received scattered dose per month from patient in 2D and 3D of 49 and 32 μSv/month at 200 cm from patient. Other staff did not receive the scattered radiation as they were not in operating room during exposure. As the occupational dose limit is 4000 μSv/month, the radiologic technologist was safe working with O-Arm system. Cumulative dose to staff can be reduced by decreasing exposure time in 2D, reduce number of scan in 3D and stay behide the control panel during exposure. In addition the staff must wear the lead apron or using the protective barrier.