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Journal of Health Sciences and Medicine

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Original Article
Incidental focal 18F-FDG uptake in colorectal locations on PET/CT for oncologic reasons: pathologic correlation with endoscopic finding
Abstract
Aims: Incidental focal 18-fluorodeoxyglucose (18F-FDG) uptake in the colorectal region on positron emission tomography/computed tomography (PET/CT) may indicate premalignant lesions, such as adenomas or malignancies. Early detection and diagnosis are crucial for cancer prevention. This study aimed to assess the characteristics of incidental focal colonic FDG uptake associated with benign, premalignant, and malignant lesions, and to determine when colonoscopy is necessary.
Methods: A retrospective review of PET/CT reports was conducted on 5.380 patients with confirmed or suspected malignancies who underwent whole-body 18F-FDG PET/CT between January 2019 and April 2024. Patients exhibiting focal colonic 18F-FDG uptake and subsequently referred for colonoscopy were included in this study.
Results: Among 110 patients who underwent colonoscopy, 63 (57.3%) had adenomas and 14 (12.7%) had malignant tumors. The receiver operating characteristic (ROC) curve based on the maximum standardized uptake value (SUVmax) showed an AUC of 0.958. A cutoff value of 13.80 was optimal for distinguishing malignant lesions from nonmalignant lesions, with a sensitivity of 92%, specificity of 89%, positive predictive value of 56%, and negative predictive value of 98%. The SUVmax significantly differentiated malignancy from other colonoscopic findings (p<0.001). No significant differences were observed between adenomas and benign or physiological findings (p>0.05).
Conclusion: The colonoscopy results indicated that malignant lesions had significantly elevated SUVmax values compared to other lesion types or physiological uptake. However, the SUVmax was not sufficient to distinguish benign lesions from adenomas. Therefore, all incidental colonic findings should be thoroughly assessed, and lesions with SUVmax ?13.80 should be promptly evaluated.

Keywords : PET/CT, focal uptake, SUVmax, colonoscopy, malignancy

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Article available in :
Volume 8, Issue 1, 2025
Page : 109-114
https://doi.org/10.32322/jhsm.1594127
Article Information
Received : 30 Kas 2024
Accepted : 22 Ara 2024
Published : 12 Oca 2025
Corresponding Author :

Salih Demirci: Department of Gastroenterology, Dr. Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital, University of Health Sciences, Ankara, Turkiye

[email protected]
Citation : Demirci S, Sezer S, Uçmak Vural G, Yüksel M, Gökbulut V. Incidental focal 18F-FDG uptake in colorectal locations on PET/CT for oncologic reasons: pathologic correlation with endoscopic finding. J Health Sci Med. 2025;8(1):109-114.

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