TY - JOUR
T1 - The diagnostic accuracy of F-18-FDG PET/CT in diagnosing fracture-related infections
AU - Lemans, Justin V.C.
AU - Hobbelink, Monique G.G.
AU - IJpma, Frank F.A.
AU - Plate, Joost D.J.
AU - van den Kieboom, Janna
AU - Bosch, Paul
AU - Leenen, Luke P.H.
AU - Kruyt, Moyo C.
AU - Glaudemans, Andor W.J.M.
AU - Govaert, Geertje A.M.
PY - 2019/4
Y1 - 2019/4
N2 - PURPOSE:
18F-Fluorodeoxyglucose positron emission tomography (
18F-FDG PET/CT) is frequently used to diagnose fracture-related infections (FRIs), but its diagnostic performance in this field is still unknown. The aims of this study were: (1) to assess the diagnostic performance of qualitative assessment of
18F-FDG PET/CT scans in diagnosing FRI, (2) to establish the diagnostic performance of standardized uptake values (SUVs) extracted from
18F-FDG PET/CT scans and to determine their associated optimal cut-off values, and (3) to identify variables that predict a false-positive (FP) or false-negative (FN)
18F-FDG PET/CT result.
METHODS: This retrospective cohort study included all patients with suspected FRI undergoing
18F-FDG PET/CT between 2011 and 2017 in two level-1 trauma centres. Two nuclear medicine physicians independently reassessed all
18F-FDG PET/CT scans. The reference standard consisted of the result of at least two deep, representative microbiological cultures or the presence/absence of clinical confirmatory signs of FRI (AO/EBJIS consensus definition) during a follow-up of at least 6 months. Diagnostic performance in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was calculated. Additionally, SUVs were measured on
18F-FDG PET/CT scans. Volumes of interest were drawn around the suspected and corresponding contralateral areas to obtain absolute values and ratios between suspected and contralateral areas. A multivariable logistic regression analysis was also performed to identify the most important predictor(s) of FP or FN
18F-FDG PET/CT results.
RESULTS: The study included 156
18F-FDG PET/CT scans in 135 patients. Qualitative assessment of
18F-FDG PET/CT scans showed a sensitivity of 0.89, specificity of 0.80, PPV of 0.74, NPV of 0.91 and diagnostic accuracy of 0.83. SUVs on their own resulted in lower diagnostic performance, but combining them with qualitative assessments yielded an AUC of 0.89 compared to an AUC of 0.84 when considering only the qualitative assessment results (p = 0.007).
18F-FDG PET/CT performed <1 month after surgery was found to be the independent variable with the highest predictive value for a false test result, with an absolute risk of 46% (95% CI 27-66%), compared with 7% (95% CI 4-12%) in patients with
18F-FDG PET/CT performed 1-6 months after surgery.
CONCLUSION: Qualitative assessment of
18F-FDG PET/CT scans had a diagnostic accuracy of 0.83 and an excellent NPV of 0.91 in diagnosing FRI. Adding SUV measurements to qualitative assessment provided additional accuracy in comparison to qualitative assessment alone. An interval between surgery and
18F-FDG PET/CT of <1 month was associated with a sharp increase in false test results.
AB - PURPOSE:
18F-Fluorodeoxyglucose positron emission tomography (
18F-FDG PET/CT) is frequently used to diagnose fracture-related infections (FRIs), but its diagnostic performance in this field is still unknown. The aims of this study were: (1) to assess the diagnostic performance of qualitative assessment of
18F-FDG PET/CT scans in diagnosing FRI, (2) to establish the diagnostic performance of standardized uptake values (SUVs) extracted from
18F-FDG PET/CT scans and to determine their associated optimal cut-off values, and (3) to identify variables that predict a false-positive (FP) or false-negative (FN)
18F-FDG PET/CT result.
METHODS: This retrospective cohort study included all patients with suspected FRI undergoing
18F-FDG PET/CT between 2011 and 2017 in two level-1 trauma centres. Two nuclear medicine physicians independently reassessed all
18F-FDG PET/CT scans. The reference standard consisted of the result of at least two deep, representative microbiological cultures or the presence/absence of clinical confirmatory signs of FRI (AO/EBJIS consensus definition) during a follow-up of at least 6 months. Diagnostic performance in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was calculated. Additionally, SUVs were measured on
18F-FDG PET/CT scans. Volumes of interest were drawn around the suspected and corresponding contralateral areas to obtain absolute values and ratios between suspected and contralateral areas. A multivariable logistic regression analysis was also performed to identify the most important predictor(s) of FP or FN
18F-FDG PET/CT results.
RESULTS: The study included 156
18F-FDG PET/CT scans in 135 patients. Qualitative assessment of
18F-FDG PET/CT scans showed a sensitivity of 0.89, specificity of 0.80, PPV of 0.74, NPV of 0.91 and diagnostic accuracy of 0.83. SUVs on their own resulted in lower diagnostic performance, but combining them with qualitative assessments yielded an AUC of 0.89 compared to an AUC of 0.84 when considering only the qualitative assessment results (p = 0.007).
18F-FDG PET/CT performed <1 month after surgery was found to be the independent variable with the highest predictive value for a false test result, with an absolute risk of 46% (95% CI 27-66%), compared with 7% (95% CI 4-12%) in patients with
18F-FDG PET/CT performed 1-6 months after surgery.
CONCLUSION: Qualitative assessment of
18F-FDG PET/CT scans had a diagnostic accuracy of 0.83 and an excellent NPV of 0.91 in diagnosing FRI. Adding SUV measurements to qualitative assessment provided additional accuracy in comparison to qualitative assessment alone. An interval between surgery and
18F-FDG PET/CT of <1 month was associated with a sharp increase in false test results.
KW - F-FDG PET/CT
KW - Diagnosis
KW - Diagnostic accuracy (either seperate or as a replacement of diagnostic performance)
KW - Diagnostic performance
KW - Fracture-related infections
KW - Infection
KW - Medical imaging
KW - Nuclear imaging
KW - Osteomyelitis
KW - Trauma
KW - Diagnostic accuracy
KW - CT
KW - F-18-FDG PET
UR - http://www.scopus.com/inward/record.url?scp=85057948521&partnerID=8YFLogxK
U2 - 10.1007/s00259-018-4218-6
DO - 10.1007/s00259-018-4218-6
M3 - Article
C2 - 30523391
AN - SCOPUS:85057948521
SN - 1619-7070
VL - 46
SP - 999
EP - 1008
JO - European Journal of Nuclear Medicine and Molecular Imaging
JF - European Journal of Nuclear Medicine and Molecular Imaging
IS - 4
ER -