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INTRODUCTION AND OBJECTIVE: The treatment and
prognosis of bladder cancer depends on lymph node
involvement in addition to other factors, but the accuracy of
conventional imaging modalities for the prediction of nodal
involvement or even detection of recurrence in early stage is
limited. This study retrospectively investigated the value of
18F-uorodeoxyglucose positron emission
tomography/computed tomography (PET/CT) in the staging
and follow up of urothelial carcinoma in comparison to
contrast-enhanced computed tomography (CT).
METHODOLOGY: We reviewed 143 les of urothelial
carcinoma patients. Of these, 113 had initial (pre-surgical) and
78 had follow-up PET/CT scans while 87 patients had initial and
81 had follow-up CT scans. Initial CT and PET/CT results were
correlated with surgical histopathology data (grade, stage and
lymph node status). Follow-up CT and PET/CT results were
conrmed by repeated imaging studies.
RESULTS: The sensitivity for detecting lymph node metastasis
before surgery was 44.23 % vs 42.1 % while the specicity was
100% vs 95.24 % for PET/CT scan vs CT scan, respectively.
PET/CT scan had a better positive predictive value for lymph
node metastasis before surgery (100 % vs 88.89 %). PET/CT
scan had higher specicity in detecting recurrence (97.83 % vs
90.20 %) with higher positive predictive value (96.88 % vs 85.71
%). There was a signicant association between recurrence
discovered by PET/CT scan and the nodal status as 82.8% of
patients who developed recurrence had positive lymph node
whereas 17.2% had negative lymph node at surgery (p<0.0001,
chi square). In addition, stage status at surgery was signicantly
associated with PET/CT scan discovered recurrence as 90% of
patients who developed recurrence were pT3 while 10%
were pT2 (p=0.001, chi square).
CONCLUSIONS: PET/CT scan is not inferior to CT scan in
detecting positive lymph nodes before surgery of urothelial
cancers while it is superior to CT scan in detecting recurrence
after surgery.