Impact of patient obesity on radiation doses received by scrub technologists during coronary angiography

Abstract

Background: The impact of patient obesity on scrub technologist radiation dose during coronary angiography has not been adequately studied.

Methods: Real-time radiation exposure data were prospectively collected during consecutive coronary angiography cases. Patient radiation dose was estimated by dose area product (DAP). Technologist radiation dose was recorded by a dosimeter as the personal dose equivalent (H_p (10)). Patients were categorized according to their body mass index (BMI): <25.0, lean; 25.0-29.9, overweight; ≥30.0, obese. The study had two phases: in Phase I (N = 351) standard radiation protection measures were used; and in Phase II (N = 268) standard radiation protection measures were combined with an accessory lead shield placed between the technologist and patient.

Results: In 619 consecutive coronary angiography procedures, significant increases in patient and technologist radiation doses were observed across increasing patient BMI categories (p < 0.001 for both). Compared to lean patients, patient obesity was associated with a 1.7-fold increase in DAP (73.0 [52.7, 127.5] mGy × cm² vs 43.6 [25.1, 65.7] mGy × cm², p < 0.001) and a 1.8-fold increase in technologist radiation dose (1.1 [0.3, 2.7] μSv vs 0.6 [0.1, 1.6] μSv, p < 0.001). Compared to Phase I, use of an accessory lead shield in Phase II was associated with a 62.5% reduction in technologist radiation dose when used in obese patients (p < 0.001).

Conclusions: During coronary angiography procedures, patient obesity was associated with a significant increase in scrub technologist radiation dose. This increase in technologist radiation dose in obese patients may be mitigated by use of an accessory lead shield.

Keywords: Body mass index; Cardiac catheterization; Obesity; Radiation safety.