There a nubmer of imagning modaliteis that can stage colon cancer. A recent study evaluated the impact of FDG-PET on the management of patients with colorectal carcinoma. They noted a change in the clinical stage and major management decisions in approximately 40% of patients. The disease was upstaged in 20 patients (80%) and downstaged in 5 patients (20%). As a result of FDG-PET findingsphysicians avoided major surgery in 41% of patients for whom surgery was the intended treatment. On the other handfalse-positive results may occur with FDG-PET in patients with abscesses from nonspecific inflammatory reactions following radiotherapy or tracer uptake in the bowelbladderor ureters.
NCCN states that PET scan is not routinely indicated.
Agrawal ANair NAgrawal RBaghel NS. Unsuspected second malignancy detection by FDG PET scan. Clin Nucl Med. Dec 2008;33(12):868-9.
Capirci CRubello DChierichetti F. Long-term prognostic value of 18F-FDG PET in patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy. AJR Am J Roentgenol. Aug 2006;187(2):W202-8.
Meta JSeltzer MSchiepers C. Impact of (18)f-fdg pet on managing patients with colorectal cancer: the referring physician''s perspective. J Nucl Med. Apr 2001;42(4):586-90.