Relationships Between Radiation Exposure Dose, Time, and Projection in Videofluoroscopic Swallowing Studies

An update on pharyngeal assessment by the modified barium swallow

The modified barium swallow study (MBSS) is a diagnostic examination that visualizes the functional anatomy and physiology of the oral pharyngeal swallowing mechanism in real time. The MBSS, a videofluoroscopic imaging method, is indicated for patients with known or suspected oropharyngeal dysphagia and ideally involves the combined expertise of a radiologist and speech pathologist. The MBSS provides critical diagnostic insights that help in identifying and assessing the type and severity of physiological swallowing impairments, evaluating the safety of oral intake, testing the effectiveness of evidence-based interventions, and developing treatment plans. This manuscript aims to present an overview of MBSS standards from an interdisciplinary perspective, emphasizes key areas of best practices, and reviews the common morphologic abnormalities seen on MBSS exams.

ESSD-ESGAR best practice position statements on the technical performance of videofluoroscopic swallowing studies in adult patients with swallowing disorders

OBJECTIVES

Videofluoroscopic swallowing studies (VFSS) remain the gold standard for the instrumental assessment of oropharyngeal swallowing disorders alongside flexible endoscopic evaluation of swallowing (FEES), requiring a high standard of quality and correct implementation. The current best practice position statements aim to guide the clinical practice of VFSS in individuals experiencing swallowing disorders.

MATERIALS AND METHODS

An international expert consensus panel with expertise in oropharyngeal dysphagia, comprised of radiologists, speech-language therapists, otolaryngologists, and other professionals in the field, convened by the European Society of Swallowing Disorders (ESSD) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), developed best practice position statements. They were established using an online Delphi methodology involving an online panel discussion and item preparation and three consecutive rounds. Consensus was reached when ≥ 80% of the participants agreed on a specific recommendation.

RESULTS

Eighteen best practice position statements were formulated, thereby establishing standard recommendations on the technical performance of VFSS. They cover VFSS planning, correct implementation, documentation, radiation protection, equipment and maintenance, and education and training.

CONCLUSION

These position statements summarise the panel's deliberations and recommendations in performing VFSS, representing the agreed consensus of experts from ESSD and ESGAR. They provide a structured framework for optimising and standardising the performance of VFSS in patients with swallowing disorders.

KEY POINTS

Question Significant regional and national differences in clinical practice when performing VFSS highlight the need for interdisciplinary recommendations to optimise patient care. Findings Eighteen statements were developed by representatives of the ESSD and the ESGAR. Clinical relevance These best practice position statements on the technical performance of VFSS may serve as a basis for standardising the procedure and ensuring high-quality service.

The Impact of Videofluoroscopic Pulse Rate on Duration and Kinematic Measures in Infants and Adults with Feeding and Swallowing Disorders

This investigation assessed the impact of temporal resolution during a videofluoroscopic evaluation of swallowing (VFSS) on measures of duration and kinematics. Thirty adult and ten infant swallow studies, all acquired at 30 frames and 30 pulses per second, were obtained from a New Mexico hospital. All swallow studies were altered to simulate 15 and 5 pulses per second. Duration measures included pharyngeal response time, duration of upper esophageal sphincter (UES) opening, velopharyngeal closure duration and total swallow duration. Kinematic measures were assessed in adults only and included peak hyoid position and extent of UES opening during the swallow. Analysis of outcome measures was performed and compared across the three temporal resolutions (30, 15, and 5 pulses per second). For data points where normative values are available, we evaluated the impact of temporal resolution on clinical determination (i.e., did a change in pulse rate alter the clinical classification). Kinematic and duration measures were altered with changes in pulse rate and these changes increased as temporal resolution decreased. For outcome measures where normative values are available, accuracy of clinical determination decreased with decreased pulse rate. Temporal resolution impacts duration and kinematic measures. However, the direction of these changes is unpredictable, indicating sensitivity and specificity are both affected. Without a predictable impact, the use of lower pulse rates may alter clinical impressions and treatment recommendations yielding inappropriate treatment goals and treatment duration.

Impact of Reducing Fluoroscopy Pulse Rate on Adult Modified Barium Swallow Studies

Modified Barium Swallow Studies (MBSS) are a critical part of the evaluation, treatment planning, and outcome assessment for persons with swallowing disorders. Since MBSSs use ionizing radiation with associated cancer risks, many clinicians have reduced radiation exposure by reducing the fluoroscopic pulse rate. However, by reducing pulse rate, we also decrease the temporal resolution of MBSSs which has been shown in pilot studies to significantly reduce diagnostic accuracy. Two hundred MBSSs from patients routinely undergoing MBSS as standard of care conducted at 30 pulses per second (pps) using the Modified Barium Swallow Study Impairment Profile (MBSImP™) standardized administration protocol were selected. A stratified sampling method ensured that a full range of swallowing impairments (etiology, type, and severity) was represented. Recordings were down sampled from 30 pps to 15, 7.5, and 4 pps. MBSSs were rated using the MBSImP components and Penetration-Aspiration Scale (PAS) score for each swallow. Percent agreement was calculated across raters for MBSImP and PAS scores by bolus type and volume. The Least-Squares Method was used for hypothesis testing. Statistically significant and clinically meaningful changes in scores of swallowing physiology and penetration/aspiration occurred when reducing pulse rate below 30pps. These changes were evident across bolus types and volumes. Given the impact on diagnostic accuracy and the low radiation risks to adults undergoing MBSSs, reducing pulse rate to 15pps or below is not aligned with the As Low As Reasonably Achievable (ALARA) principle and should not be used as a viable method to reduce radiation exposure from MBSSs.

Assessing Dysphagia in the Adult

This article explores the landscape of dysphagia assessment in adults. Dysphagia, a complex condition affecting the lifespan and many health conditions, significantly compromises individuals' quality of life. Dysphagia is often underdiagnosed, emphasizing the need for comprehensive assessment methods to ensure timely and accurate intervention. It encompasses clinical history, physical examination, clinical and instrumental swallow evaluations. Procedures within each of these modalities are reviewed, highlighting strengths, limitations, and contribution toward a complete understanding of dysphagia, ultimately guiding effective intervention strategies for improved patient outcomes.

Usefulness of barium sulfate and iohexol as contrast agents for VFSS in visualizing components of swallowing predictable of poor outcomes

Barium sulfate and iohexol are commonly used as contrast agents for videofluoroscopic swallowing study (VFSS). This study compared their usefulness as contrast agents in visualizing components of swallowing predictable of subsequent pneumonia and unintentional weight loss after VFSS. This was a randomized, controlled, crossover trial. The two contrast agents were alternately used in the same participants, and the order in which the contrast agent was tested first was randomly assigned. After VFSS, we followed the participants for 3 months and the association between VFSS findings of each contrast agent and the subsequent pneumonia and unintentional weight loss were analyzed. A total of 30 participants were included in the analysis. We recorded 11 cases of subsequent pneumonia and 13 of unintentional weight loss. Regarding the risk of subsequent pneumonia after VFSS, only the oral transit time and number of swallows tested with barium sulfate indicated significant differences between participants with and without subsequent pneumonia. For unintentional weight loss, oral transit time and pharyngeal wall coating after swallowing tested with barium sulfate, as well as oral transit time, nasal penetration, residue in the valleculae, PAS scores, and number of swallows when testing with iohexol demonstrated significant differences between those with and without unintentional weight loss.

Implementation of Esophageal Screening in an Outpatient Hospital-Based Setting: A Quality Improvement Project

PURPOSE

Despite evidence supporting interconnectivity of oropharyngeal and esophageal swallowing, evaluation and treatment are dichotomized. When the videofluoroscopic swallowing study (VFSS) only considers oropharyngeal swallowing, the full scope of swallowing impairment may be missed. A lower rate of esophageal screening in an outpatient hospital setting may result from lack of speech-language pathologist (SLP) training and understanding of screening feasibility. This project was an internal quality improvement project (QIP) at Mayo Clinic in Arizona to (a) educate and train SLPs on conducting the Robust Esophageal Screening Test (REST) and (b) determine the feasibility of REST protocol implementation in a multidisciplinary swallow clinic.

METHOD

Fishbone analysis was used to identify potential causes of the gap in quality. Six Sigma methodology was used to outline the QIP. SLPs were trained in the REST protocol. To ensure adequate training, reliability ratings were assessed with the Cohen's kappa statistic. Esophageal screening via REST was implemented as an adjunct to the standard protocol during VFSS over a 3-month period for referred patients with dysphagia. Clinical findings were recorded.

RESULTS

All clinical rater SLPs reached the threshold of κ = .8 to ensure adequate rater reliability. Among 136 outpatients who underwent esophageal screening via REST, 100 patients completed the full REST screening and 36 completed a partial REST screening. Of the 100 full screenings, 80 patients had a failed screening, which indicated a potential esophageal swallowing impairment. Findings were discussed by members of the multidisciplinary dysphagia care team.

CONCLUSIONS

The results of this QIP show that focusing on assessment of dysfunction and interplay across the swallowing continuum can substantially improve patient care by expediting and specifying next steps of the multidisciplinary dysphagia care team.

A Tutorial on Diagnostic Benefit and Radiation Risk in Videofluoroscopic Swallowing Studies

The videofluoroscopic swallowing study (VFSS) is a key tool in assessing swallowing function. As with any diagnostic procedure, the probable benefits of the study must be weighed against possible risks. The probable benefit of VFSS is an accurate assessment of swallowing function, enabling patient management decisions potentially leading to improved patient health status and quality of life. A possible (though highly unlikely) risk in VFSS is carcinogenesis, arising from the use of ionizing radiation. Clinicians performing videofluoroscopic swallowing studies should be familiar with both sides of the risk benefit equation in order to determine whether the study is medically justified. The intent of this article is to provide the necessary background for conversations about benefit and risk in videofluoroscopic swallowing studies.

The use of videofluoroscopy (VFS) and fibreoptic endoscopic evaluation of swallowing (FEES) in the investigation of oropharyngeal dysphagia in stroke patients: A narrative review

OBJECTIVES

Patients with suspected acute stroke require rapid assessment of swallowing on admission. If aspiration is suspected, this takes the form of specialist assessment, using either videofluoroscopy (VFS) or fibreoptic endoscopic evaluation of swallowing (FEES). The review aim was to evaluate and compare the effectiveness of each method in stroke patients. Literature was collected from the databases Scopus, Web of Science and Medline, and articles included in the review were published within the last 10 years, in the English language.

KEY FINDINGS

Sensitivity and specificity ranged from 0.29-0.33 and 0.96-1.0 for VFS, respectively, and 0.37-1.0 and 0.65-0.87 for FEES, respectively, depending on the type of bolus utilised. VFS is the current gold-standard for the investigation of oropharyngeal dysphagia (OD), however, radiation dose and patient transport implications mean FEES may be preferred. FEES has limitations including 'whiteout' and the invasive nature of the endoscope. The NICE guidelines do not recommend a definitive protocol specifically in stroke patients. This suggests further research may be required to determine the most effective method.

CONCLUSION

FEES is a beneficial first line examination, providing limited invasiveness, and administering a high level of patient suitability, without using ionising radiation. VFS could potentially be useful following FEES to secure full visualisation, ensuring an aspiration event is not missed during FEES.

IMPLICATIONS FOR PRACTICE

Use of FEES as the first line test rather than VFS, ensures radiation dose is as low as reasonably practicable (ALARP). Ongoing research to ensure protocols follow current best practice can help ensure accurate management of oropharyngeal dysphagia in stroke patients.

The American Broncho-Esophagological Association Position Statement on Swallowing Fluoroscopy

OBJECTIVES

To develop an expert consensus statement on the clinical use of swallowing fluoroscopy in adults that reduces practice variation and identifies opportunities for quality improvement in the care of patients suffering from swallowing impairment.

METHODOLOGY

A search strategist reviewed data sources (PubMed, Embase, Cochrane, Web of Science, Scopus) to use as evidence for an expert development group to compose statements focusing on areas of controversy regarding swallowing fluoroscopy. Candidate statements underwent two iterations of a modified Delphi protocol to reach consensus.

RESULTS

A total of 2184 publications were identified for title and abstract review with 211 publications meeting the criteria for full text review. Of these, 148 articles were included for review. An additional 116 publications were also included after reviewing the references of the full text publications from the initial search. These 264 references guided the authors to develop 41 candidate statements in various categories. Forty statements encompassing patient selection, fluoroscopic study choice, radiation safety, clinical team dynamics, training requirements, videofluoroscopic swallow study and esophagram techniques, and interpretation of swallowing fluoroscopy met criteria for consensus. One statement on esophagram technique reached near-consensus.

CONCLUSIONS

These 40 statements pertaining to the comprehensive use of swallowing fluoroscopy in adults can guide the development of best practices, improve quality and safety of care, and influence policy in both the outpatient and inpatient settings. The lack of consensus on some aspects of esophagram technique likely reflects gaps in knowledge and clinical practice variation and should be a target for future research. Laryngoscope, 133:255-268, 2023.

Stakeholder Perspectives on Radiation Use and Interdisciplinary Collaboration in Adult Modified Barium Swallow Studies

The Modified Barium Swallow Study (MBSS) is a videofluoroscopic examination of the anatomy and physiology involved in swallowing. Like other fluoroscopic examinations, the MBSS uses ionizing radiation with related radiation risks. Thus, the procedures and protocols related to MBSSs must balance the benefit of the diagnostic information gained with the risk of radiation exposure. This requires complex decision-making for any given clinician but becomes complicated due to the interprofessional nature of conducting MBSSs, namely the direct involvement of both the speech-language pathologist and radiologist with indirect involvement of the medical physicist and the referring physician. This editorial provides the perspectives of the various stakeholder groups related to radiation use in adult MBSSs, identifies barriers to conducting MBSSs in an evidence-based manner, and suggests areas for improvement.

Radiation Effective Doses to Adults Undergoing Modified Barium Swallow Studies

Modified Barium Swallow Studies (MBSSs) are important tests to aid the diagnosis of swallowing impairment and guide treatment planning. Since MBSSs use ionizing radiation, it is important to understand the radiation exposure associated with the exam. This study reports the average radiation dose in routine clinical MBSSs, to aid the evidence-based decision-making of clinical providers and patients. We examined the MBSSs of 200 consecutive adult patients undergoing clinically indicated exams and used kilovoltage (kV) and Kerma Area Product to calculate the effective dose. While 100% of patients underwent the exam in the lateral projection, 72% were imaged in the upper posterior-anterior (PA) projection and approximately 25% were imaged in the middle and lower PA projection. Average kVs were 63 kV, 77 kV, 78.3 kV, and 94.3 kV, for the lateral, upper, middle, and lower PA projections, respectively. The average effective dose per exam was 0.32 ± 0.23 mSv. These results categorize a typical adult MBSS as a low dose examination. This value serves as a general estimate for adults undergoing MBSSs and can be used to compare other sources of radiation (environmental and medical) to help clinicians and patients assess the risks of conducting an MBSS. The distinction of MBSS as a low dose exam will assuage most clinician's fears, allowing them to utilize this tool to gather clinically significant information about swallow function. However, as an X-ray exam that uses ionizing radiation, the principles of ALARA and radiation safety must still be applied.

Visualizing the Esophagus During Modified Barium Swallow Studies: A Systematic Review

Purpose Despite the emphasis on using evidence-based practice for patient care, as clinicians, we sometimes find that there is insufficient evidence to support our clinical practices. One example of this is the "contentious" inclusion of routine, standardized visualization of the esophagus during modified barium swallow studies (MBSSs). This review sought to investigate the evidence for inclusion of routine esophageal visualization during the MBSS, a practice that is supported by the long-established interrelationship between all aspects of the oral, pharyngeal, and esophageal swallowing continuum. Method Searches were conducted in PubMed, Scopus, and CINAHL databases. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed to identify articles that met prespecified inclusion and exclusion terms. Results Five articles were included in this review, which identified that esophageal findings were present in 48.67% of those participants whose MBSS included esophageal visualization. Conclusion This review supports a standardized, validated, reliable visualization protocol of the esophagus during the MBSS as a critical component to the accurate diagnosis and formulation of treatment recommendations for patients with swallowing disorders.

Radiation exposure in modified barium swallow studies

PURPOSE OF REVIEW

The modified barium swallow study (MBSS) is an X-ray examination of swallowing used to detect the presence and type impairment, aspiration risk, and to develop intervention plans. In this review, we will cover the use of ionizing radiation in MBSSs and review recent literature concerning radiation exposure and cancer risks to patients undergoing MBSSs. Lastly, we will discuss the clinical implications of these findings.

RECENT FINDINGS

Recent literature confirms that the MBSS is a low-dose examination and that reducing pulse rate negatively impacts diagnostic accuracy. Importantly, cancer risks to adults undergoing MBSSs were also reported to be low.

SUMMARY

An adult undergoing MBSS using a standardized, valid protocol, like the Modified Barium Swallow Impairment Profile (MBSImP), has low-radiation exposure and very low associated cancer risks. MBSSs should be used whenever relevant to adult patient care without undue concern regarding radiation exposure. Children also have low radiation exposure from MBSSs; however, cancer risks from that exposure remain unknown. Best practices in radiation safety must always be followed. Reducing pulse rates in the adult or pediatric population to reduce radiation exposure is not a valid strategy because of the resulting reduction in diagnostic accuracy.

Best Practices in Modified Barium Swallow Studies

Purpose The modified barium swallow study (MBSS) is a widely used videofluoroscopic evaluation of the functional anatomy and physiology of swallowing that permits visualization of bolus flow throughout the upper aerodigestive tract in real time. The information gained from the examination is critical for identifying and distinguishing the type and severity of swallowing impairment, determining the safety of oral intake, testing the effect of evidence-based frontline interventions, and formulating oral intake recommendations and treatment planning. The goal of this review article is to provide the state of the science and best practices related to MBSS. Method State of the science and best practices for MBSS are reviewed from the perspectives of speech-language pathologists (SLPs) and radiologists who clinically practice and conduct research in this area. Current quandaries and emerging clinical and research trends are also considered. Results This document provides an overview of the MBSS and standards for conducting, interpreting, and reporting the exam; the SLPs' and radiologist's perspectives on standardization of the exam; radiation exposure; technical parameters for recording and reviewing the exam; the importance of an interdisciplinary approach with engaged radiologists and SLPs; and special considerations for examinations in children. Conclusions The MBSS is the primary swallowing examination that permits visualization of bolus flow and swallowing movement throughout the upper aerodigestive tract in real time. The clinical validity of the study has been established when conducted using reproducible and validated protocols and metrics applied according to best practices to provide accurate and reliable information necessary to direct treatment planning and limit radiation exposure. Standards and quandaries discussed in this review article, as well as references, provide a basis for understanding the current best practices for MBSS.