Detection of infective endocarditis with [⁶⁴Cu]Cu-DOTATATE positron emission tomography/computed tomography: a case series

Background Infective endocarditis (IE) is a serious and fatal condition, with prosthetic valve endocarditis representing the worst prognosis. The recommended nuclear imaging modality 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography ([¹⁸F]FDG PET/CT) has limitations. In this case series, we present two patients with IE scanned with a novel PET tracer [⁶⁴Cu] Cu-DOTATATE ([⁶⁴Cu]Cu-[1,4,7,10-tetraazacyclododecane-N,N′,N″,N‴-tetra acetic acid]-d-Phe1, Tyr3-octreotate). ^{Case summary} An 84-year-old female patient (Patient 1) with a biological mitral valve prosthesis (MVP) was admitted acutely from the outpatient clinic. Transoesophageal echocardiography showed vegetations on the MVP. The patient underwent [⁶⁴Cu]Cu-DOTATATE PET/ CT, which showed uptake at the site of infection. The patient underwent surgical valve replacement. The post-operative period was without significant complications, and the patient was discharged home. In another case, a 72-year-old male patient (Patient 2) with a medical history of mild mitral valve stenosis, aortic valve stenosis, and gastrointestinal stromal tumour was admitted to the hospital for back and abdominal pain and subfebrile episodes. Transoesophageal echocardiography showed large vegetations in the native aortic valve. The patient underwent [⁶⁴Cu]Cu-DOTATATE PET/CT, which showed no uptake at the site of the suspected infection. The patient underwent surgical valve replacement. The post-operative period was characterized by Candida albicans sternitis, and after prolonged hospitalization, the patient died of respiratory failure as a complication of sepsis. Discussion In conclusion, this is the first case series presenting two patients with definite IE (modified Duke criteria), who were scanned with the novel [⁶⁴Cu]Cu-DOTATATE PET/CT. Patient 1, with endocarditis in the MVP, showed an uptake of the tracer, while Patient 2, with native aortic valve endocarditis, did not show any uptake.