How to interpret gastroesophageal reflux disease (GERD) in an adult patient with symptoms of heartburn, regurgitation, and dysphagia using a sulphur colloid radionuclide study?

Interpretation of Gastroesophageal Reflux Using Sulfur Colloid Scintigraphy

Sulfur colloid gastroesophageal reflux scintigraphy has limited diagnostic utility in adults with GERD symptoms and should not be used as a primary diagnostic test, as it lacks standardized methodology, has variable sensitivity (79% in pediatric studies), and is inferior to 24-hour esophageal pH monitoring for establishing a diagnosis. 1

Primary Diagnostic Limitations

Lack of Standardization

• Methodology and interpretation criteria for reflux scintigraphy are not uniform between centers, making results difficult to compare and interpret consistently 1
• The examination technique varies widely in terms of patient positioning, study duration, and quantification methods 1

Poor Diagnostic Performance

• When compared to 24-hour esophageal pH monitoring (the gold standard), reflux scintigraphy demonstrates only 79% sensitivity 1
• False-negative examinations are common in patients with delayed gastric emptying, requiring either prolonged imaging beyond 60 minutes or confirmatory pH probe evaluation 1
• The brief observation period during scintigraphy results in missed reflux episodes that occur outside the imaging window 1

Technical Considerations for Interpretation

Study Protocol

• Tc-99m sulfur colloid is mixed with feeding or a meal and administered to the patient 1
• A 1-hour scintigraphic study formatted in 60-second frames provides quantitative representation of postprandial gastroesophageal reflux 1
• Some centers advocate placing patients in multiple positions during scanning, which may increase detection yield by approximately 3-fold compared to supine-only positioning 1

What Constitutes a Positive Study

• Visualization of radiotracer activity ascending from the stomach into the esophagus indicates reflux 1
• Quantification includes the number of reflux episodes and the height of reflux in the esophagus 1
• Detection of radiotracer in the lungs on delayed imaging (Tc-99m sulfur lung scintigraphy) may suggest aspiration, though this finding requires correlation with clinical symptoms 1

Clinical Context Where This Test May Be Considered

Pediatric Population (Limited Role)

• Use may be limited to patients older than 3 months of age after other modalities have excluded anatomic causes of feeding disorders 1
• In symptomatic and asymptomatic preterm infants, reflux scintigraphy demonstrated high incidence of reflux in both groups that did not correlate with symptoms, limiting its clinical utility 1

Adult Population (Not Recommended)

• 24-hour esophageal pH monitoring remains the single best test to establish a cause-effect relationship between GERD and symptoms in adults 1, 2
• Upper endoscopy is preferred for detecting mucosal complications of GERD 1
• Barium esophagography is superior for identifying anatomic abnormalities 1

Preferred Diagnostic Approach for Adults with GERD Symptoms

Clinical Diagnosis

• Predominant heartburn and regurgitation assessed by physician interview is the most accurate approach to diagnosing GERD, rather than relying solely on patient-reported symptoms 1
• Typical GERD symptoms (heartburn, regurgitation) are often sufficient for empirical PPI therapy without testing 3

When Objective Testing Is Required

• Patients who do not respond to empirical PPI therapy should undergo 24-hour esophageal pH monitoring off all acid suppression to maximize detection of abnormal acid exposure and symptom-reflux association 1
• Upper endoscopy is indicated for patients with alarm symptoms (dysphagia, weight loss, bleeding) or risk factors for esophageal adenocarcinoma 3
• Esophageal manometry should be performed before considering anti-reflux surgery 4

Common Pitfalls to Avoid

• Do not order sulfur colloid scintigraphy as a first-line test for GERD diagnosis in adults—it provides inferior diagnostic information compared to pH monitoring and lacks standardization 1
• Do not interpret a negative scintigraphy study as excluding GERD, given the high false-negative rate 1
• Do not use scintigraphy to guide treatment decisions, as symptom-reflux correlation is better established with pH/impedance monitoring 1
• Avoid relying on lung scintigraphy for diagnosing aspiration without strong clinical correlation, as lipid-laden macrophages and bronchoscopic findings may provide more direct evidence 1