The additional role of 18F-FDG PET/CT in prosthetic valve endocarditis

Abstract. – OBJECTIVE: The purpose of the
present review is an update on the diagnosis
of prosthetic valve endocarditis (PVE), evaluating
the additional value of 18F-fluorodeoxyglucose
positron emission tomography/computed
tomography (18F-FDG PET/CT) to the standard
modified DUKE criteria on which for a long time
is based the diagnostic strategy of the disease.
MATERIALS AND METHODS: We did a comprehensive
research on the studies reported in
the literature and regarding the employment of
18F-FDG PET/CT in the early diagnosis of PVE in
patients with suspected disease. Scientific databases
have been examined such as Medline and
PubMed, followed by a review of citations and
reference lists. The research included the following
terms: infective endocarditis, prosthetic
heart valve and cardiac valve replacement infections,
18F-FDG PET/CT and endocarditis.
RESULTS: The recent studies reported in the
literature on the PVE diagnostic approaches
showed elevated sensitivity and specificity values
of 18F-FDG PET/CT ranging from 73 to 96.6%
and from 80 to 94%, respectively, reducing the
number of misdiagnosed patients. The usefulness
of the radioisotopic procedure is even
more important when the other diagnostic conventional
diagnostic tools, such as echocardiography,
are inconclusive or negative in patients in
whom the diagnosis of PVE is definitively ascertained.
However, false negative and positive results
of 18F-FDG PET/CT were also ascertained
in some studies interfering with image interpretation
even if such limitation can be reduced
with an adequate patient preparation, with a better
knowledge of clinical course of the disease,
of the treatment in progress and of the different
technical aspects of the method.
CONCLUSIONS: In different studies reported
in the literature, 18F-FDG PET/CT proved to improve
the diagnostic accuracy of the conventional
modified DUKE criteria in patients with suspected
IE, and in particular with PVE, giving the
highest diagnostic performance and providing
additional diagnostic benefits. Thus, the radioisotopic
hybrid procedure should be included in
the diagnostic protocol of PVE as complementary
tool to modified DUKE criteria. Finally, the
usefulness of 18F-FDG PET/CT in monitoring the
response to antibiotic therapy, although the few
data reported in the literature are encouraging,
needs more numerous studies and with a major
number of cases.