Recurrence of colorectal tumors: PET evaluation.
Positron emission tomography (PET) was used in the follow-up of patients with colorectal malignancies to differentiate between recurrent colorectal tumor and scar. Patients were examined with oxygen-15-labeled water and with fluorine-18-labeled deoxyglucose (FDG). FDG was injected intravenously to assess tumor metabolism. The tracer concentration was quantitatively evaluated by means of a region-of-interest technique and standardized for both injected dose and body volume. Of 29 patients, 21 had recurrent colorectal malignancy, and eight had a nonmalignant mass. All malignancies were seen on the PET cross sections. Nonmalignant lesions had a low FDG accumulation on images obtained 60 minutes after injection. While the tumor-soft tissue ratio was highest shortly after the intravenous injection of FDG, the tumor-scar ratio was highest 60 minutes after injection. It was possible to differentiate tumor from non-malignant tissue with FDG with the use of standardized concentration values and tumor-soft tissue ratios. Imaging with O-15-labeled water gave no additional information.
Institut für Radiologie und Pathophysiologie, Deutsches Krebsforschungszentrum, Heidelberg, Federal Republic of Germany.
L G
LG
Strauss
J H
JH
Clorius
P
P
Schlag
B
B
Lehner
B
B
Kimmig
R
R
Engenhart
M
M
Marin-Grez
F
F
Helus
F
F
Oberdorfer
P
P
Schmidlin
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002921:Cicatrix / Q000000981:diagnostic imaging; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D014055:Tomography, Emission-Computed