Role of Positron Emission Tomography in Assessing Disease Activity in Ulcerative Colitis: Comparison with Biomarkers
Disease activity in ulcerative colitis (UC) is best assessed clinically by Mayo score. 18-Fluorodeoxyglucose positron emission tomography-computerized tomography (FDG PET-CT) is a noninvasive imaging technique to assess extent, disease activity and response to treatment of UC, especially in high risk population or patients unwilling for endoscopy.
We conducted a prospective observational study with the aim of assessing and correlating UC disease activity by clinical criteria, endoscopy, histology, serum and fecal biomarkers, and FDG PET-CT.
Sixty eligible patients of UC were enrolled into three groups (26 remission, 24 moderate and 10 severe activity) as per Mayo score and FDG PET-CT was performed within 72 h of colonoscopy. ESR, CRP, and fecal calprotectin (FC) levels were determined for all patients.
Of 60 enrolled patients, 10% patients had proctitis, 43.3% left-sided colitis, and 46.7% extensive colitis. ESR, CRP, FC levels, and rectal PET activity were significantly higher in groups with moderate and severe disease activity. Rectal PET activity showed a significant correlation with the Mayo score (k = 0.465, p < 0.001), endoscopic subscore (k = 0.526, p < 0.001), histological score (k = 0.496, p < 0.001), and FC (k = 0.279, p = 0.031). Extent evaluation by FDG PET-CT and colonoscopy showed a significant correlation (k = 0.582, p < 0.001). Besides, FDG PET-CT identified sacroiliitis in one patient and adenocarcinoma in one patient.
FDG PET-CT is a reliable noninvasive tool for detection of disease activity, extent in UC with good correlation with Mayo score, histology and fecal biomarkers and accurate predictor of disease remission.
KeywordsUlcerative colitis Positron emission tomography Fecal calprotectin Endoscopy
Inflammatory bowel disease
Clostridium difficile toxin assay
- 18-FDG PET
Positron emission tomography with 18-fluorodeoxyglucose
NB helped in literature search, figures, study design, data collection, data analysis, data interpretation, and writing. SKS involved in study design, data analysis, and data interpretation. AB helped in study design, data collection, data analysis, and PET-CT scans. KKP involved in histopathological analysis. CV helped in biochemical tests, stool tests, data collection, and data analysis. KV helped in histopathological analysis. JS involved in data collection, data analysis, and data interpretation. RP involved in data collection. ND helped in data interpretation. RK involved in study design, data analysis, and data interpretation.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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