The application of Fluoredeoxyglucose positron emission tomography/CT to detect the recurrence and metastasis of colorectal cancer

Objective: To evaluate the clinical value of positron emission tomography/ computed tomography(PET/CT) with fluorine-18-labeled fluorodeoxyglucose(18F-FDG) in dectecting and diagnosing the recurrence and metastasis of colorectal cancer.Methods: The results of whole-body PET/CT of 68 patients with colorectal cancer were analyzed retrospectively.The average follow-up time was 15.8 months.The diagnosis of recurrence tumor and/or metastasis was based on pathologic examination,colonoscopy,multi-modality imaging and clinical follow-up.Results: Fifty-five of the 68 patients had recurrence and /or metastasis but no recurrence was found in the other 13 cases.The sensitivity,specificity and accuracy of PET/CT in detecting recurrent and metastatic tumor were 96.4%,76.9% and 92.6% respectively.PET/CT successfully detected one or several malignant insidious lesions in 8 cases with negative findings by CT and /or ultrasonography,and it revaeled more malignant lesions than CT and ultrasonography in 30.9%(17/55)of the patients.The clinical therapeutic strategies were changed in 11 case duo to the results of PET/CT,and the influence rate of PET/CT was 16.2%.The metastasis was mainly confined in the liver,lung,peritoneal cavity and retroperitoneal region.In the examination of the 24 patients with increased serum CEA,the positive rate of PET/CT was 91.7%.Conlusion: PET/CT can detect the recurrence and metastasis of colorectal cancer with high sensitivity and accuracy.