Radiation safety for pain physicians: principles and recommendations

Abstract

C-arm fluoroscopy is a useful tool for interventional pain management. However, with the increasing use of C-arm fluoroscopy, the risk of accumulated radiation exposure is a significant concern for pain physicians. Therefore, efforts are needed to reduce radiation exposure. There are three types of radiation exposure sources: (1) the primary X-ray beam, (2) scattered radiation, and (3) leakage from the X-ray tube. The major radiation exposure risk for most medical staff members is scattered radiation, the amount of which is affected by many factors. Pain physicians can reduce their radiation exposure by use of several effective methods, which utilize the following main principles: reducing the exposure time, increasing the distance from the radiation source, and radiation shielding. Some methods reduce not only the pain physician's but also the patient's radiation exposure. Taking images with collimation and minimal use of magnification are ways to reduce the intensity of the primary X-ray beam and the amount of scattered radiation. It is also important to carefully select the C-arm fluoroscopy mode, such as pulsed mode or low-dose mode, for ensuring the physician's and patient's radiation safety. Pain physicians should practice these principles and also be aware of the annual permissible radiation dose as well as checking their radiation exposure. This article aimed to review the literature on radiation safety in relation to C-arm fluoroscopy and provide recommendations to pain physicians during C-arm fluoroscopy-guided interventional pain management.

Keywords: Fluoroscopy; Interventional; Ionizing; Pain; Procedural; Radiation; Radiation Dosage; Radiation Effects; Radiation Exposure; Radiography; Radiology; Safety; Scattering; X-Rays..

Fig. 1

Three major causes of radiation exposure: primary X-ray beams (yellow), scattered X-rays (red), and leakage X-rays (blue).

Fig. 2

Depending on the location of the X-ray generator, the parts of the body exposed to scattered X-rays vary. When an image is taken with the X-ray generator (red circle) positioned below (A), more scattered radiation is generated in the lower extremities of the physician and medical staff [9]. When a lateral view is taken (B), more scattered radiation is generated on the side where the X-ray generator is located [14]. If the flat panel detector is positioned downwards to obtain an image (C), a large amount of scattered radiation is generated to the upper body, neck, and head. The red circle is X-ray generator.

Fig. 3

Personal protective devices. Three types of commercially available lead aprons: (A) front type, (B) wraparound type, and (C) skirt and vest type. Various types of eye shields: (D) wraparound type, (E) side shield type, and (F) face shield.

Fig. 4

Defects in the shields are found using fluoroscopic images. The most common site of damage to the radiation-protective shields was at the waist of the aprons (51%) [51]. (A) One-piece-type apron and (B) skirt-type apron. Adapted from the article of Ryu et al. (Korean J Pain 2013; 26: 142-7) [51].

Fig. 5

Reduce radiation exposure by changing the C-arm fluoroscopy mode. (A) Comparison of the radiation absorbed dose (RAD) in the C-arm fluoroscopic mode [54]. The graph shows the time, RADs, mean RADs/mean time, and current (mA) according to the C-arm modes. The pulsed fluoroscopic mode of 15 frames per second is used. *P < 0.050. ^aUnit is expressed as second for time, mRADs/cm² for RADs, mRADs/cm² • second for RADs/Time, and mA for current. (B) The differences in radiation exposure in relation to collimation in the medial branch block [56]. Comparison between the effective dose on left chest of the operator and the side of the table among groups. Chest, *P = 0.042; table, *P = 0.025. (C) Comparison of RAD between the control and collimation groups, *P = 0.001. Adapted from the article of Cho et al. (Korean J Pain 2011; 24: 199-204) [54]; Baek et al. (Korean J Pain 2013; 26: 148-53) [56].