Detection of Recurrent Colorectal Cancer by 18F-FDG PET/CT Comparison with Contrast Enhanced CT Scan
Sunanta Chiewvit MD*, Titiporn Jiranantanakorn MD*, Piyaporn Apisarnthanarak MD**, Potjanee Kanchaanapiboon MSc*, Chompunoot Hannanthawiwat MSc*, Kritaya Ubolnuch MNS*, Nopparat Phongsawat BSc*, Pipat Chiewvit MD**
Affiliation : * Division of Nuclear Medicine, Department of Radiology, Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Division of Diagnosis, Department of Radiology, Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To evaluate diagnostic performance of 18F-FDG PET/CT in assessment of recurrence colorectal cancer after
treatment in Siriraj Hospital.
Material and Method: The authors retrospectively studied 48 treated colorectal cancer patients with suspected recurrence
who underwent 18F-FDG PET/CT and contrast-enhanced CT (CECT). Clinical information, image follow-up for at least
one year, and pathological reports of the patients were reviewed for gold standard.
Results : Recurrent or metastatic disease was found in 36 of 48 patients. Calculated sensitivity, specificity, and accuracy of
18F-FDG PET/CT were 94.4%, 66.7%, and 87.5%. 18F-FDG PET/CT can reduce false positive results of CECT in six patients,
thus specificity of 18F-FDG PET/CT was statistically significantly better than that of CECT. Using lesion-based analysis
with 65 recurrent sites and 26 non-recurrent lesion, 18F-FDG PET/CT showed better sensitivity 87.7%, specificity 61.5%,
and accuracy 80.2 than CECT without statistical significance.
Conclusion : 18F-FDG PET/CT overall showed higher sensitivity, specificity, and accuracy than CECT.
Keywords : 18F-FDG PET/CT, Recurrent colon cancer
