Preoperative localization of distal colorectal tumours.

Background: The detection of true localization of the tumour are crucial to driving the proper treatment algorithm in distally-located colorectal cancers (CRCs). The performance of four methods; colonoscopy, computed tomography (CT), magnetic resonance imaging (MRI), and fluoro-deoxy-glucose-positron emission tomography scan (FDG/PET-CT), were evaluated to identify the localizations of distal colorectal malignancies according to the rectum, sigmoid colon and recto- sigmoid junction (RSJ).

Materials And Methods: Medical records of patients who underwent colorectal surgery for tumours located on the sigmoid colon, RSJ, or rectum were reviewed retrospectively.

Methods: In total, 156 patients were included in the study. In terms of overall accuracy, colonoscopy, CT, MRI and FDG/PET-CT had similar accuracy rates, with 74%, 67%, 75%, and 74%, respectively. Colonoscopy was relatively less sensitive for rectosigmoid tumours (33%), while CT was less sensitive for rectal tumours (26%). MRI was less specific for tumours located on the rectum (33%).

Conclusions: It is crucial to correctly identify the location of distal colorectal tumours in order to plan accurate treatment strategies. Preoperative modalities, including colonoscopy, CT, MRI, and FDG/PET-CT, do not provide excellent accuracy for tumours of the distal colorectal tumours. To increase the success of these modalities; combined use could be more successful.

Key Words: Colonoscopy, Computed tomography Distal colorectal cancer, Magnetic resonance imaging.