Radiation Risks to Adult Patients Undergoing Modified Barium Swallow 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.

Fluoroscopy Time of Radiologist-Monitored Modified Barium Swallow Exams in Oncology: A 3-year Single Institution Retrospective Study

Fluoroscopy time is an important metric for radiation safety, but how it is related to dysphagia severity as graded by Dynamic Grade of Swallowing Toxicity (DIGEST) criteria and other factors in oncology practice is undocumented. We evaluated the fluoroscopy time for the bolus protocol used at the originating institution of the DIGEST method and assessed the relationship between fluoroscopy time and DIGEST grade, exam indication, and additional parameters. Eleven trials, including specified VARIBAR® barium volumes, were included in the standard bolus protocol. Electronic health record (EHR) 2018-2021 databases were sampled in a retrospective STARI-guided DIGEST implementation evaluation for clinically reported DIGEST grades in the EHR and matched to fluoroscopy time. The study sample included 4,162 modified barium swallow (MBS) examinations. Using generalized linear modeling, we tested log-transformed fluoroscopy time associations with Tukey's adjustment for multiple pairwise comparisons. MBS duration ranged from 0.16 to 11.80 min (Median 2.21, IQR 1.98). Fluoroscopy time was associated with exam indication, cancer diagnosis, setting, and DIGEST grade. Fluoroscopy times increased as the DIGEST severity grade worsened (R2 = 0.45, p < .0001). MBS indication was also associated with fluoroscopy time (R2 = 0.12, p < .0001), with the shortest times for baseline exams and the longest for excluding leaks (Median1.6 vs. 3.5 min). Median fluoroscopy time was shorter among endocrine and metastatic cancer patients and longer among head and neck cancer patients (2 vs. 3 min, R2 = 0.02, p < .0001). Inpatient examinations were longer than outpatient (Median 3.1 vs. 2.2 min, R2 = 0.02, p < .0001). The bolus protocol was clinically acceptable within ALARA standards. Clinicians should be mindful of increased fluoroscopy time and optimize exams as clinically indicated in patients with severe dysphagia, leak exclusion, and inpatient studies.

Anterior-Posterior View Acquisition During Videofluoroscopy: A Survey Study Exploring Influential Factors on Speech-Language Pathologists' Practice Patterns

PURPOSE

This study explored factors influencing speech-language pathologists' (SLPs') decision making surrounding anterior-posterior (AP) view inclusion practices during videofluoroscopic swallowing studies (VFSSs) in the United States.

METHOD

SLPs completing VFSSs were recruited to complete an online anonymous survey. Questions represented six constructs of interest including: (a) clinician demographics, (b) practice patterns, (c) diagnostic perceptions, (d) professional influences, (e) training and education, and (f) logistical facilitators and barriers. Binary logistic regression was used to explore the relationship between construct items and likelihood of AP view inclusion.

RESULTS

A total of 136/213 (64%) of respondents reported obtaining an AP view routinely. Facilitators of AP view inclusion were post-acute work setting (OR = 3.40, p = .001); perception that department practices "probably" (OR = 5.65, p = .006) or "definitely" align (OR = 5.30, p = .006) with evidence-based practice; perception the AP view has "a lot" (OR = 4.17, p = .025) or "a great deal" (OR = 4.77, p = .028) of diagnostic value; perception that their department is "definitely" supportive (OR = 4.69, p = .040); "moderate" (OR = 4.75, p = .001) or "no" (OR = 7.51, p < .001) equipment limitations; and radiologist support greater than "extremely unsupportive or resistant" ("somewhat unsupportive" [OR = 5.74, p = .041], "neutral" [OR = 11.23, p = .002], "somewhat supportive" [OR = 13.92, p = .001], or "extremely supportive" [OR = 13.92, p = .001]). Barriers to AP view inclusion were geographic location in the southern U.S. census region (OR = 0.31, p = .007), being "significantly" influenced by coworker opinions (OR = 0.13, p = .018), and productivity tracking (OR = 0.21, p = .008).

CONCLUSION

Environmental factors and organizational culture heavily influence AP view inclusion practices.

Videofluoroscopic Swallowing Studies: A Proposed Checklist

PURPOSE

The videofluoroscopic swallowing study (VFSS) is used widely in dysphagia research. However, variations exist in the conduct and interpretation of VFSS, including differences in contrast agents, food and fluid consistencies tested, patient positioning, intervention strategies trialed, fluoroscopy settings, resolution, and image storage solutions. It cannot be assumed that VFSS exams yield directly comparable results across different studies. It is essential that relevant elements of VFSS be clearly reported in research. The goal of this article is to outline optimal VFSS reporting as part of the Framework for RigOr aNd Transparency In REseaRch on Swallowing (FRONTIERS), a critical appraisal tool intended to promote rigor and transparency in dysphagia research.

METHOD

We developed a set of 27 questions regarding the rigor and transparency of VFSS reporting, based on review of previous research articles. These were reviewed by all members of the FRONTIERS Framework collaborative, to determine which questions were mandatory, unnecessary, or needed revision, prior to inclusion in the final critical appraisal tool.

RESULTS

The final FRONTIERS Framework tool contains 20 questions and seven subquestions regarding VFSS. These are grouped into four themes: patient/participant positioning, equipment and recording settings, contrast agents, and rating methods, including operational definitions and reliability.

CONCLUSIONS

The VFSS section of the FRONTIERS Framework tool is intended to facilitate and promote rigorous and transparent reporting of all elements that may influence the interpretation of VFSS in research. This critical appraisal tool can also be used to guide research design and the evaluation of study outcomes contributing to best practices in the field of dysphagia research.

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.

Acid-Resistant Near-Infrared II Ag2Se Quantum Dots for Gastrointestinal Imaging

With the development of near-infrared II (NIR-II) fluorescence imaging, Ag2Se quantum dots (QDs) have become promising label candidates due to their negligible toxicity and narrow band gap. Despite their potential for gastrointestinal (GI) imaging, the application of Ag2Se QDs still presents significant challenges due to issues such as fluorescence extinction or poor stability in the complex digestive microenvironment. Herein, we have proposed a novel approach to the continuous production of Se precursors using glutathione (GSH) as the reductant under acidic conditions, realizing the continuous growth of water-dispersible Ag2Se QDs. The Ag2Se QDs emitting at 600-1100 nm have been successfully synthesized. Meanwhile, the silver-rich surface of the synthesized NIR-II Ag2Se QDs has been passivated well with the dense GSH, resulting in exceptional colloidal stability and photostability and endowing them with acid resistance. As a result, the obtained NIR-II Ag2Se QDs have exhibited remarkable stability in gastric acid, thus enabling their utilization for long-term real-time monitoring of GI peristalsis via NIR-II fluorescence imaging. Moreover, in contrast to conventional barium meal-based X-ray imaging, NIR-II fluorescence imaging with as-prepared NIR-II Ag2Se QDs can offer clearer visualization of fine intestinal structures, with a width as small as 1.07 mm. The developed strategy has offered a new opportunity for the synthesis of acid-resistant nanocrystals, and the acid-resistant, low-toxicity, and biocompatible NIR-II Ag2Se QDs synthesized in this work show a great promise for GI imaging and diagnosis of GI diseases in vivo.

Post-POEM Contrast-Enhanced Swallow Study: Is It Always Necessary?

BACKGROUND

Peroral endoscopic myotomy (POEM) is rapidly becoming the procedure of choice for treating esophageal achalasia. In most centers, contrast-enhanced swallow studies (CESS) are routinely performed postoperatively to confirm mucosal integrity. The aim of this study was to determine the necessity of performing these studies routinely after POEM.

METHODS

A retrospective review of a prospectively maintained database of patients who underwent POEM between December 2012 and November 2020 was performed. All patients underwent a CESS on the first postoperative day. Medical records including vital signs, complete blood count, and POD-1 CESS were evaluated.

RESULTS

One hundred thirty-four consecutive patients were included in the study. Sixty-nine (51.49%) CESS showed abnormal findings; while most findings did not change the postoperative course, five (7.2%) demonstrated tunnel leaks, which did alter the overall management. Screening patients for fever, tachycardia, or leukocytosis on POD-1 had a 100% sensitivity and a 62% specificity for finding a clinically significant complication on CESS.

CONCLUSIONS

The study findings suggest that performing routine contrast-enhanced swallow studies on all patients is not necessary following POEM, as leaks can be screened for by clinical or laboratory abnormalities. Herein, we propose an algorithm based on objective measurable findings for the selection of patients who should undergo CESS.

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.

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.

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.

Pharyngoesophageal Segment Distention Across Volumes and Pathology

Purpose Patients receive multiple bolus trials during a videofluoroscopic swallowing study (VFSS) to assess swallow function, inclusive of narrowing within the pharyngoesophageal segment (PES). While differences in the narrowest and widest segments are visualized, the ratio of distention across boluses is not well understood. Method A retrospective review of 50 consecutive VFSSs with five boluses of varied viscosity and volume was performed. Still images at maximal PES distention were captured and scaled using a 19-mm disk. Measurements of the narrowest and widest segments were obtained, and a distention ratio was calculated. Studies were categorized by PES phenotype as normal, esophageal web, cricopharyngeal bar, or narrow PES. PES distention ratios were evaluated across bolus trials and within PES phenotypes using a mixed-methods repeated-measures analysis of variance. Results Of the 50 studies, there were 11 normal, 16 web, 10 bar, and 13 narrow PES. Quantitative differences were present for the narrowest (p = .01) and widest (p = .002) points across bolus volumes. No difference was present in distention ratio (p = .2) across volumes. Evaluating the PES phenotype, web, normal, bar, and narrow PES distention ratios differed (p = .03). Bar and PES narrow distention ratios were lower compared to that of the normal group (p = .01 for normal vs. bar and p = .02 for normal vs. PES narrow). Conclusions PES distention ratio stability across varying bolus volumes and phenotypes suggests that a reduction in trials during a VFSS may permit an equivalent PES evaluation to traditional exams. Ultimately, this could improve our understanding and accurate diagnosis of PES dysfunction.

Swallowing dysfunction after minimally invasive oesophagectomy

OBJECTIVES

Patients undergoing oesophagectomy frequently experience malnutrition, which in combination with the catabolic effects of surgery can result in loss of muscle mass and function. Safe swallowing requires preservation of muscle mass. Swallowing dysfunction puts postoperative patients at risk for aspiration and pneumonia. Modified Barium Swallow Study (MBSS) enables assessment of postoperative swallowing impairments. The current study assessed incidence and risk factors associated with swallowing dysfunction and restricted diet at discharge in patients after oesophagectomy in a high-volume surgical centre.

METHODS

Patients with an MBSS after oesophagectomy were identified between March 2015 to April 2020 at a high-volume surgical centre. Swallowing was quantitatively evaluated on MBSS with the Rosenbek Penetration-Aspiration Scale (PAS). Muscle loss was evaluated clinically with preoperative hand grip strength (HGS). Univariable and multivariable logistic and linear regression analyses were performed.

RESULTS

129 patients (87% male; median age 66 years) underwent oesophagectomy with postoperative MBSS. Univariate analysis revealed older age, preoperative feeding tube, lower preoperative HGS and discharge to non-home were associated with aspiration or penetration on MBSS. Age and preoperative feeding tube remained as independent predictors in the multivariable analysis. Both univariate and multivariable analyses revealed increased age and preoperative feeding tube were associated with diet restrictions at discharge.

CONCLUSIONS

Swallowing dysfunction after oesophagectomy is correlated with increased age and need for preoperative enteral feeding tube placement. Further research is needed to understand the relationship between muscle loss and aspiration with the goal of enabling preoperative physiological optimisation and patient selection.

Oesophageal screening during videofluoroscopy: International practices and perspectives of speech-language pathologists

Purpose: The aim of this study was to investigate international oesophageal screening (OS) practices during videofluoroscopy (VFS) amongst speech-language pathologists (SLPs) and to establish SLP perspectives regarding OS during VFS.Method: A 25-item online survey was developed and disseminated internationally. Respondents were SLPs with dysphagia and VFS experience. Information was sought on OS practices and perspectives. Descriptive statistics were used to analyse results.Result: A total of 202 SLPs completed the survey from USA, UK, Ireland, New Zealand, Australia and Austria. Fifty-eight per cent (n = 117/202) of SLPs internationally include an OS during VFS. This rate varies across USA (81%; 91/113), UK (69%; 18/26) and Ireland (60%; 18/30). Only 25% (29/117) of SLPs use a validated OS protocol. Most SLPs perform an OS in an anterior-posterior view (55%; 64/117) with patients seated (54%; 64/117). Bolus consistencies administered vary greatly. SLPs evaluate oesophageal bolus clearance (81% (95/117), bolus redirection (64%; 75/117), oesophageal transit time (49%; 57/117) and oesophageal pathology (11%; 13/117). Perceived challenges include scope of practice, patient positioning, protocol uncertainty and multidisciplinary support.Conclusion: Over half of SLPs internationally responding to the survey include an OS during VFS. Few follow validated protocols and analysis practices vary. OS guidelines and training opportunities are needed to ensure validated OS protocols are adopted into clinical practice.

Aspects of the assessment and management of pharyngoesophageal dysphagia

Swallowing complaints are common and may have significant consequences for nutrition and pulmonary health. Etiology varies and different aspects of the deglutitive system may be affected. A thorough assessment from the oral cavity to the stomach will provide physiologic information that enables specific targeted management plans to be devised. Although the swallow trajectory bridges anatomic areas, there has previously been a tendency to compartmentalize assessment and treatment by arbitrary anatomic boundaries. It is now clear that this approach fails to appreciate the complexity of swallow mechanics and that systems (oral, pharyngeal, esophageal, and pulmonary) are intertwined and codependent. Swallowing specialists from different backgrounds and with complementary skill sets form a multidisciplinary team that can provide insight and address multiple areas of management. With the advent of new tools for instrumental evaluation, such as manometry, targeted rehabilitative strategies can be informed by physiology, increased in precision and breadth, and assessed quantitatively. Surgical approaches have evolved toward endoscopic techniques, and food technology is expanding options in dietary management. The multidisciplinary team is core to managing this varied and often neglected patient population. This review is for clinicians treating swallowing disorders and will explore the selected aspects of the assessment and management of pharyngoesophageal swallowing disorders.

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.

The Landscape of Videofluoroscopy in the UK: A Web-Based Survey

Videofluoroscopy (VFS) is considered one of the gold-standard assessments of swallowing. Whilst guidelines for the application and conduct of VFS exist, their translation into clinical practice remain challenging. To build a greater understanding on how VFS clinics operate in the UK. A web-based survey was shared with speech and language therapists (SLTs) working in VFS clinics via professional networks and social media from October 2018 to January 2019. 101 responses were received. Two thirds of clinics were SLT-led, with the majority of clinics being run by two SLTs (73.6%) and a radiographer (95.5%) also known as radiologic technologists, diagnostic radiographers and medical radiation technologists. Less than 50% of radiographers had received specialist training. Around half of the clinics used a standard assessment or analysis protocol and 88.1% a rating scale. Set recipes for a range of textures were used in 53.4% of VFS clinics. Barium and water soluble contrasts were used, but only 15.8% knew the concentration of contrast used. The most commonly reported VFS pulse and frame rate was 15 per second. There was evidence of a lack of SLT knowledge regarding technical operation of VFS. Screening times varied from 0.7–10 min (median 3 min, IQR 2.5–3.5). Around 50% of respondents reported quality issues affecting analysis. In a survey of UK SLTs, translation of VFS guidance into practice was found to be limited which may impact on the quality of assessment and analysis. Collaboration with radiology, strengthening of guidelines and greater uptake of specialist training is deemed essential.

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

Purpose Clinicians are trained to rely on radiation exposure time as an indicator of patient radiation exposure in Videofluoroscopic Swallowing Studies (VFSSs). However, it has been shown in other medical uses of fluoroscopy that dose area product (DAP), the amount of radiation delivered to the patient, is a better indicator of overall patient radiation exposure than radiation exposure time. This study sought to understand the relationship of DAP in VFSSs with radiation exposure time and projection used (lateral vs. posterior-anterior [PA]). Method DAP, radiation exposure time, and projection were recorded in 200 adults undergoing clinically indicated VFSSs conducted in accordance with the Modified Barium Swallow Impairment Profile guidelines. Data were analyzed using Spearman correlation and related sample Wilcoxon test. Results DAP and radiation exposure time did not correlate significantly in the lateral or upper PA projections. DAP was significantly higher in the PA compared to lateral projection (p < .01); however, time was shorter in PA versus lateral (p < .01). The average mGy-cm² per second was 7 for lateral projections, 14 for upper PA projections, 17 for middle PA projections, and 34 for lower PA projections. Conclusions Radiation exposure time and DAP do not strongly correlate across VFSSs. Specifically, this means that 1 patient can have a low radiation exposure time with a high DAP relative to another person with a higher radiation exposure time but a lower DAP. The results of this study question the common clinical practice of using time (specifically the 5-min indicator) as a threshold for radiation exposure during a VFSSs.