The value of using fludeoxyglucose positron-emission tomography scan with respect to colorectal abnormalities—a cross-sectional study

Abstract

Background: Fludeoxyglucose positron-emission tomography (FDG-PET) shows colic uptake regularly. Complementary colonoscopy is done. Aim: study the findings of colonoscopy. Methods: All consecutive scans in 5 years were studied. Focal FDG uptake in colon and/or rectum were scored as + or ++. Clinical files and endoscopy reports were studied for final diagnosis. Results: Focal FDG uptake was noted in 173 out of 2,075 scans (8.4%). Focal FDG activity was judged ++ in 73 patients (42.2%) and + in 100 (57.8%). The majority of colorectal cancers scored ++. Patients with ++ activity underwent or had undergone significantly more often a colonoscopy compared with patients with + activity, 82% versus 65% (P=0.02). FDG PET/CT was false positive with respect to polyp(s) or cancer in 13 cases (22%) of ++ FGD activity and in 38 cases of + FDG (P<0.001). In 25 patients a total of 69 polyps were not FDG avid. Conclusions: FDG-PET scanning is a useful tool in oncology. However, false-positive and false-negative findings with respect to colonic uptake are present in a significant number of patients. If the clinical condition and the potential prognosis allows the performance of colonoscopy this procedure should be done.

Colonoscopy following the positron emission tomography/computed tomography scan in patients with incidental colorectal uptake: what is the most effective management?

“…A whole body scan with PET-CT is performed for a cancer suspicion or the staging of a diagnosed cancer, and sometimes it may show an incidental FDG uptake in any part of the body. PET-CT is considered a useful technique in CRC and has been shown to have extra value in the detection of disease recurrence 8 . Following the first report by Yasuda et al in 1998 showing an increased 18 F-FDG uptake in a colonic adenoma 9 , several studies have evaluated its ability to detect CRC.…”

68Ga-FAPI-04 Versus 18F-FDG PET/CT in a Case of Peutz-Jeghers Syndrome

“…4 It may be difficult to discriminate gastrointestinal polyps or adenomas from cancer on FDG PET because both can show increased FDG uptake. [5][6][7][8][9] In this case, the intestinal polyps showed increased FDG uptake and no FAPI uptake, suggesting that FAPI PET may have the potential to differentiate gastrointestinal polyps or adenomas from cancer, which need further investigation.…”

“…Although hamartomatous polyps are generally assumed to have a low malignant potential, malignant transformation within the polyps has been observed in patients with Peutz-Jeghers syndrome 4. It may be difficult to discriminate gastrointestinal polyps or adenomas from cancer on FDG PET because both can show increased FDG uptake [5][6][7][8][9]. In this case, the intestinal polyps showed increased FDG uptake and no FAPI uptake, suggesting that FAPI PET may have the potential to differentiate gastrointestinal polyps or adenomas from cancer, which need further investigation.…”