Radiation exposure of patients during mini C-arm use: an audit in 2032 procedures

Diagnostic Reference Levels for Common Orthopedic Hand and Wrist Procedures Using Intraoperative Mini C-arm Fluoroscopy

BACKGROUND

Diagnostic reference levels are radiation dose levels in medical radiodiagnostic practices for typical examinations for groups of standard-sized individuals for broadly defined types of equipment. This study aimed to contribute to national diagnostic reference levels for common hand and wrist procedures using mini C-arm fluoroscopy. Small joint and digital fracture procedure diagnostic reference levels have not been reported in significant numbers previously with procedure-level stratification.

METHODS

Data were collected from fluoroscopy logbooks and were cross-referenced against the audit log kept on fluoroscopy machines. A total of 603 procedures were included.

RESULTS

The median radiation dose for wrist fracture open fixation was 2.73 cGycm2, Kirschner wiring (K-wiring) procedures was 2.36 cGycm2, small joint arthrodesis was 1.20 cGycm2, small joint injections was 0.58 cGycm2, and phalangeal fracture fixation was 1.05 cGycm2.

CONCLUSIONS

Wrist fracture fixation used higher radiation doses than phalangeal fracture fixation, arthrodeses, and injections. Injections used significantly less radiation than the other procedures. There are significant differences in total radiation doses when comparing these procedures in hand and wrist surgery. National and international recommendations are that institutional audit data should be collected regularly and should be stratified by procedure type. This study helps to define standards for this activity by adding to the data available for wrist fracture diagnostic reference levels and defining standards for digital and injection procedures.

Investigating Patient-Level Radiation Exposure in Hand and Wrist Fracture Surgery

BACKGROUND

Although occupational exposure to radiation has been previously studied in the hand surgery literature, there is a paucity of studies looking at radiation exposure to the patient during fluoroscopy-guided hand surgery. We aimed to describe the level of radiation experienced by patients undergoing common hand and wrist fracture fixation and to identify risk factors for increased radiation exposure.

METHODS

We performed a retrospective review of patients at a single institution who underwent fracture fixation of the hand, wrist, or forearm requiring mini c-arm fluoroscopic guidance from 2016 to 2020. Data points collected included patient demographics, procedural details, and indicators of radiation exposure including dose-area product (DAP), total intraoperative images, and total fluoroscopy time. Effective dose (ED) was calculated using DAP, field size, and a previously established conversion factor.

RESULTS

The final sample included 361 patients with an average age of 46 years. Procedures included fixation of forearm fractures (3.3%), distal radius fractures (35.7%), metacarpal fractures (30.8%), and phalangeal fractures (30.2%). The median number of intraoperative images acquired was 36, median total fluoroscopy time was 43 seconds, median DAP was 4.8 cGycm2, and median ED was 0.13 μSv. Distal (metacarpal and phalangeal) fractures required more intraoperative images and longer total fluoroscopy time (49 images, 61 seconds) compared with proximal (forearm and distal radius) fractures (39 images, 47 seconds) (images, P = 0.004; exposure time, P = 0.004). However, distal fractures had a lower average ED compared with proximal fractures (0.15 vs 0.19 μSv, P = 0.020). When compared with open procedures, percutaneous procedures had higher DAPs (8.8 vs 4.9 cGycm2, P < 0.001), higher ED (0.22 vs 0.15 μSv, P < 0.001), more intraoperative images (65 vs 36 images, P < 0.001), and longer total fluoroscopy time (81.9 vs 44.4 seconds, P < 0.001).

CONCLUSIONS

Patient-level radiation exposure during fluoroscopy-guided hand and wrist procedures is low relative to other common imaging modalities, such as dental radiographs, chest x-rays, and computed tomography scans, and is comparable with less than a few hours of natural background radiation exposure, highlighting the overall safety of this important technology. Further study should be performed to establish reference ranges, which could lead to improved patient counseling and evidence-based guidelines on patient shielding.

Establishing local diagnostic reference levels for mini C-arm use in upper limb surgery - A step towards national audit

AIMS

Under the Ionising Radiation Medical Exposure Regulations, hospitals using fluoroscopy and image intensifiers should monitor doses from exposures using ionising radiation. There is a need for national diagnostic reference levels to advise Orthopaedic and Plastic surgeons on safe screening times and radiation doses for patients having upper limb surgical procedures.

METHODS

Retrospective study of all patients who underwent upper limb surgical procedures requiring intra-operative mini C-arm image intensifier use at our hospital between 2013 and 2019. This included results from three machines in different rooms. Procedures were classified as closed and open procedures.

RESULTS

Information on a total of 2910 procedures over 6 years (June 2013 to June 2019) were obtained. 133 procedures with incomplete data and 4 cases of lower extremities were excluded. 1719 closed procedures had a median dose area product of 0.48 cGycm² and median screening time of 7 s, compared to 1054 open procedures, with a median dose area product of 1.88 cGycm² and median screening time of 28 s. National diagnostic reference levels are set at the third quartile and indicate the difference between good and poor practice. For diagnostic reference levels, we suggest a dose area product of 0.82 cGycm² and a screening time of 11 s for closed procedures and a dose area product of 3.07 cGycm² and screening time of 40 s for open procedures. Public Health England state that national diagnostic reference levels should be derived from multiple patients, radiology rooms and hospitals. Our data meets the first two criteria and is an initial step in establishing national diagnostic reference levels for upper limb mini C-arm use.

CONCLUSIONS

This large audit reports results, which, with further work across multiple hospital sites, should lead to establishing national diagnostic reference levels for mini C-arm fluoroscopy for upper limb Orthopaedic procedures.