We evaluated the role of gallium-68-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-Nal3-octreotide (68Ga-DOTA-NOC) PET/CT in assessing sarcoidosis disease activity.Patients and methods
Patients diagnosed with sarcoidosis underwent 68Ga-DOTA-NOC-PET/CT. The maximum standardized uptake value (SUVmax) at the pathological site and in the descending thoracic aorta (reference standard, SUVmed) were assessed. A SUVmax/SUVmed ratio (disease activity score) of more than one was considered a marker of active disease and was compared with the clinical symptoms and serum angiotensin-converting enzyme and computed tomography (CT) scan. The primary outcome was to assess the efficacy of the scan in estimating disease activity.Results
Of the 39 patients enrolled in the study, 27 patients were symptomatic and the rest were asymptomatic at enrollment. Increased disease activity was present in 25 (92%) of the 27 symptomatic patients and two (16%) of the 12 asymptomatic patients. The sensitivity and specificity of the test were 92.5% (95% confidence interval=75.7–99.0) and 83.3% (95% confidence interval=51.5–97.9), respectively. Seven out of nine patients who became asymptomatic after treatment showed a significant decrease in the mean disease activity score in post-treatment scans (3.38±1.05 vs 1.20±0.82, P<0.001).Conclusion
68Ga-DOTA-NOC PET/CT emerged as a useful tool to assess the disease activity and treatment response in patients with sarcoidosis with thoracic involvement.