Clinical significance of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in the follow-up of colorectal cancer: searching off approaches increasing specificity for detection of recurrence
Article Category: Research Article
Published Online: Nov 01, 2017
Page range: 378 - 385
Received: Jul 19, 2017
Accepted: Sep 10, 2017
DOI: https://doi.org/10.1515/raon-2017-0045
© 2017 Semra Ince, Kursat Okuyucu, Oguz Hancerliogulları, Engin Alagoz, Huseyin San, Nuri Arslan
This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background
Nearly 40% of colorectal cancer (CRC) recurs within 2 years after resection of primary tumor. Imaging with fluorine-18-fluorodeoxyglucose (l8F-FDG) positron emission tomography/computed tomography (PET/CT) is the most recent modality and often applied for the evaluation of metastatic spread during the follow-up period. Our goal was to study the diagnostic importance of 18F-FDG-PET/CT data of maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG) and the difference of SUVmax on dual-time imaging in CRC.
Patients and methods
We examined the SUVmax value of lesions on control or restaging 18F-FDG-PET/CT of 53 CRC patients. All lesions with increased SUVmax values were confirmed by colonoscopy or histopathology. We compared PET/CT results with conventional imaging modalities (CT, MRI) and tumor markers (carbohydrate antigen 19-9 [Ca 19-9], carcinoembryonic antigen [CEA]).
Results
Mean SUVmax was 6.9 ± 5.6 in benign group, 12.7 ± 6.1 in malignant group. Mean TLG values of malignant group and benign group were 401 and 148, respectively. 18F-FDG-PET/CT was truely positive in 48% of patients with normal Ca 19-9 or CEA levels and truely negative in 10% of cases with elevated Ca 19-9 or CEA. CT or MRI detected suspicious malignancy in 32% of the patients and 18F-FDG-PET/CT was truely negative in 35% of these cases. We found the most important and striking statistical difference of TLG value between the groups with benign and recurrent disease.
Conclusions
Although SUVmax is a strong metabolic parameter (p = 0.008), TLG seems to be the best predictor in recurrence of CRC (p = 0.001); both are increasing the specificity of 18F-FDG-PET/CT.