First-In-Human Study of [64Cu]Cu-DOTATATE PET/CT in Infective Endocarditis: A Prospective Head-to-Head Comparison With [18F]FDG.

BACKGROUND

Infective endocarditis (IE) can be challenging to diagnose. Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[18F]-fluoro-d-glucose ([18F]FDG) is recommended as a diagnostic tool in the guidelines, but holds limitations. The aim of this study was to compare the tracer uptake between the novel [64Cu]Cu-DOTATATE, which has low cardiac uptake and does not require fasting or dietary restrictions, and [18F]FDG in patients with IE and examine the sensitivity and specificity.

METHODS

The CuDOS study (Cu-Dotatate Positron Emissions Tomography in Infective Endocarditis) was a prospective study including 20 patients with IE (10 with prosthetic valve endocarditis and 10 with native valve endocarditis) and 20 controls. All participants underwent [64Cu]Cu-DOTATATE and [18F]FDG PET/CT. Scans were read blinded to clinical data. Tracer uptakes were measured as maximum standardized uptake values in each heart valve. Differences were tested with Wilcoxon rank tests.

RESULTS

The median age of the cases and controls was 68 years (interquartile range [IQR], 55.0-75.5) and 61 years (IQR, 57.0-69.5), respectively. [64Cu]Cu-DOTATATE uptake (median maximum standardized uptake value [IQR]) in patients with IE was higher than in controls (2.34 [1.40-3.23] versus 1.44 [1.21-1.60]; P =0.008), although this difference was mainly driven by prosthetic valve endocarditis cases (3.23 [2.02-3.86]; P <0.001) and not between native valve endocarditis cases and controls (1.51 [1.23-2.58]; P=0.428). The sensitivity of [64Cu]Cu-DOTATATE and [18F]FDG PET/CT in 20 cases versus 20 controls were equal, and the specificity was 90% and 75%, respectively. The analysis of prosthetic valve endocarditis versus the 20 controls showed equal sensitivity (80%), and a specificity of 90% and 75%, respectively (P =0.38). In addition, a greater proportion of scans achieved diagnostic certainty with [64Cu]Cu-DOTATATE PET/CT compared with [18F]FDG PET/CT for native valve endocarditis, prosthetic valve endocarditis, and controls.

CONCLUSIONS

[64Cu]Cu-DOTATATE PET/CT showed uptake in the infected valve in patients with IE, and has major advantage as it does not require any preparation compared with [18F]FDG. [64Cu]Cu-DOTATATE had a numerically higher specificity than [18F]FDG, although the difference was not statistically significant. Both tracers were limited in the detection of native valve endocarditis.

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05432427. www.clinicaltrialsregister.eu; Unique identifier: 2021-005501-27.