Patients' and Physicians' Knowledge of Radiation Exposure Related to Spine Surgery

Michelle C. Scott, MD; Anoop R. Galivanche, BS; Elbert J. Mets, BA; Neil Pathak, MD; Joseph B. Kahan, MD, MPH; Patrick J. Burroughs, BS; Arya G. Varthi, MD; Lee E. Rubin, MD; Jonathan N. Grauer, MD

Disclosures

Spine. 2020;45(22):E1507-E1515. 

In This Article

Abstract and Introduction

Abstract

Study Design: Cross-sectional survey.

Objective: Examine patients' and physicians' estimates of radiation exposure related to spine surgery.

Summary of Background Data: Patients are commonly exposed to radiation when undergoing spine surgery. Previous studies suggest that patients and physicians have limited knowledge about radiation exposure in the outpatient setting. This has not been assessed for intraoperative imaging.

Methods: A questionnaire was developed to assess awareness/knowledge of radiation exposure in outpatient and intraoperative spine care settings. Patients and surgeons estimated chest radiograph (CXR) equivalent radiation from: cervical and lumbar radiographs (anterior-posterior [AP] and lateral), computed tomography (CT), magnetic resonance imaging (MRI), intraoperative fluoroscopy, and intraoperative CT (O-arm). Results were compared to literature-reported radiation doses.

Results: Overall, 100 patients and 26 providers completed the survey. Only 31% of patients were informed about outpatient radiation exposure, and only 23% of those who had undergone spine surgery had been informed about intraoperative radiation exposure. For lumbar radiographs, patients and surgeons underestimated CXR-equivalent radiation exposures: AP by five-fold (P < 0.0001) and seven-fold (P < 0.0001), respectively, and lateral by three-fold (P < 0.0001) and four-fold (P = 0.0002), respectively. For cervical CT imaging, patients and surgeons underestimated radiation exposure by 18-fold (P < 0.0001) and two-fold (P = 0.0339), respectively. For lumbar CT imaging, patients and surgeons underestimated radiation exposure by 31-fold (P < 0.0001) and three-fold (P = 0.0001), respectively. For intraoperative specific cervical and lumbar imaging, patients underestimated radiation exposure for O-arm by 11-fold (P < 0.0001) and 22-fold (P = 0.0002), respectively. Surgeons underestimated radiation exposure of lumbar O-arm by three-fold (P = 0.0227).

Conclusion: This study evaluated patient and physician knowledge of radiation exposure related to spine procedures. Underestimation of radiation exposure in the outpatient setting was consistent with prior study findings. The significant underestimation of intraoperative cross-sectional imaging (O-arm) is notable and needs attention in the era of increased use of such technology for imaging, navigation, and robotic spine surgery.

Level of Evidence: 4

Introduction

Imaging is an integral part of contemporary diagnosis and treatment of spinal conditions. Besides magnetic resonance imaging (MRI), most imaging modalities used in spine care involve radiation (plain radiography, computed tomography [CT], and fluoroscopy). Understanding the potential for radiation exposures is important in the office, hospital, as well as in the operating room.

The emitted dose of radiation is the radiation generated to produce the desired imaging. The effective dose takes into account the radiosensitivities of the tissues exposed by the emitted dose (expressed in millisievert [mSv]).[1] To put effective doses of radiation into an understandable framework, they are often referred to as the number of equivalent chest radiographs (CXR).[2] The mSv and equivalent CXRs of commonly used spine imaging and background radiation values have been reported in the literature and are shown in Table 1 and Table 2.[2–27]

Multiple studies have demonstrated an association between iatrogenic radiation exposure and elevated cancer risk.[19,28,29] A study by Brenner et al found that radiation from a single full-body CT scan (C3 to pubic symphysis) is associated with an increased lifetime risk of mortality from cancer of 0.08%.[30] Similarly, Smith-Bindman et al[31] noted that, after undergoing a CT coronary angiography at age 40 years, one in 270 women and one in 600 men developed cancer attributable to that scan.

In line with previous studies suggesting that patients have limited understanding of radiation exposure from medical imaging,[2,32–34] a study by Bohl et al demonstrated that patients had a poor understanding of radiation exposure associated with outpatient spine imaging.[35] This questionnaire study found that patients consistently underestimated radiation exposure of commonly used spinal imaging modalities, especially from cervical and lumbar CT scans by over 49-fold.

The above-noted study by Bohl et al evaluated the understanding of patients who are awake and aware of imaging used to assess their spine. However, imaging is also increasingly being performed during various spinal surgeries. With advancing surgical techniques and rising frequency of minimally invasive surgery, navigation, and robotics, more intraoperative imaging studies are being performed. Patient and provider understanding of radiation specific to patients undergoing surgery has not been previously assessed to our knowledge.

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