Staging of primary colorectal carcinomas with fluorine-18 fluorodeoxyglucose whole-body PET: correlation with histopathologic and CT findings.
OBJECTIVE
To evaluate the diagnostic usefulness of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) in patients with primary colorectal carcinomas.


METHODS
Forty-eight patients with biopsy-proved (n = 44) or high clinical suspicion for (n = 4) colorectal cancer underwent whole-body PET after intravenous administration of 10 mCi (370 MBq) of FDG. FDG PET results were correlated with computed tomographic (CT), surgical, and histopathologic findings.


RESULTS
PET depicted all known intraluminal carcinomas in 37 patients (including two in situ carcinomas) (sensitivity, 100%), but findings were false-positive in four of seven patients without cancer (three with inflammatory bowel conditions, one who had undergone polypectomy). Specificity was 43% (three of seven patients); positive predictive value, 90% (37 of 41 patients); and negative predictive value, 100% (three of three patients). No FDG accumulation was noted in 35 hyperplastic polyps. FDG PET depicted lymph node metastases in four of 14 patients (sensitivity, 29%). Results were similar to those obtained with CT (true-positive, two of seven patients [sensitivity, 29%]; true-negative, 22 of 26 patients [specificity, 85%]). FDG PET depicted liver metastases in seven of eight patients and was superior to CT, which depicted liver metastases in three patients (sensitivity of 88% and 38%, respectively). FDG PET and CT, respectively, correctly depicted the absence of liver metastases in 35 and 32 patients (specificity, 100% and 97%; negative predictive value, 97% and 86%).


CONCLUSIONS
FDG PET has a high sensitivity and specificity for detection of colorectal carcinomas (primary and liver metastases) and appears to be superior to CT in the staging of primary colorectal carcinoma.
Abdel-Nabi
H
H
Department of Nuclear Medicine, State University of New York at Buffalo, NY 14214, USA.
Doerr
R J
RJ
Lamonica
D M
DM
Cronin
V R
VR
Galantowicz
P J
PJ
Carbone
G M
GM
Spaulding
M B
MB
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D000368:Aged; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18