Positron emission tomography to stage suspected metastatic colorectal carcinoma to the liver.
BACKGROUND
Accurate detection of recurrent colorectal carcinoma remains a clinical challenge. Positron emission tomography (PET) using 18F-fluorodeoxyglucose (18FDG) is an imaging technique that allows direct evaluation of cellular metabolism. 18F-fluorodeoxyglucose PET was compared to computed tomography (CT) and CT portography for staging metastatic colorectal carcinoma.


METHODS
Twenty-four patients previously treated for colorectal carcinoma who had suspected recurrence to the liver underwent an 18FDG PET scan of the entire body. All patients had either a CT scan of the abdomen (n = 17), a CT portogram (n = 18), or both (n = 11). The final diagnosis was obtained by tissue pathology in 19 patients and clinical follow-up in 5 patients.


RESULTS
A total of 60 suspicious lesions were identified. Of the 55 intrahepatic lesions, 39 were malignant and 16 were benign. Of the 5 extra-hepatic lesions, 4 were malignant. The 18FDG PET imaging had a higher accuracy (93%) than CT and CT portography (both 76%) in detecting metastatic disease to the liver, and detected unsuspected extrahepatic recurrence in 4 patients. Although the sensitivity of 18FDG PET (90%) was slightly lower than that of CT portography (97%), the specificity was much higher (100% versus 9%), including postsurgical sites. 18FDG PET altered surgical plans in 6 (25%) of 24 patients.


CONCLUSIONS
18FDG PET is extremely useful in staging patients with suspected metastatic colorectal carcinoma to the liver.
Vitola
J V
JV
Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2675, USA.
Delbeke
D
D
Sandler
M P
MP
Campbell
M G
MG
Powers
T A
TA
Wright
J K
JK
Chapman
W C
WC
Pinson
C W
CW
D015179:Colorectal Neoplasms / Q000473:pathology*; D003847:Deoxyglucose / Q000031:analogs & derivatives; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose