Accuracy of preoperative computer tomography scan staging of gastric and colorectal cancer at Muhimbili National Hospital

Abstract

ABSTRACT Background: Computed Tomography (CT) has been used in the initial detection, staging and follow-up of malignant tumors regardless of the site of the primary lesion. For patients with gastric and colorectal malignancy, the disese can be detected by CT scan and help in a proper staging and treatment plan . This study aimed at determining the accuracy of preoperative CT scan staging of gastric and colorectal cancer managed at Muhimbili National Hospital (MNH). Methods: Cross-sectional study carried out between March 2017 and February 2018. All patients with gastric and colorectal cancer with CT scan, where CT TNM findings were compared to intraoperative ones. Intraoperative staging was considered the gold standard and a 2X2 contingency table was constructed. Specificity, sensitivity, accuracy and predictive values were computed. Results: A total of 58 participants were recruited in this study. The CT was found to have sensitivity, specificity, accuracy, positive and negative predictive value of 0.0% to 94.1%, 14.3 to 100%, 54% to 84%, 0.0% to 100% and 47% to 95% respectively in detecting TNM in gastric cancer. Also CT was found to have sensitivity, specificity, accuracy, positive and negative predictive value of 0.0% to 88%, 55% to 100%, 51% to 94%, 0.0% to 100%, and 42% to 94% respectively in detecting TNM in colorectal cancer. Conclusion: The CT scan was found to be highly sensitive in detecting the disease confined to the primary organ (gastric or colorectal) and highly specific in detecting disease metastasis to lymphnode, liver and peritoneum. It has good accuracy in staging colorectal cancer and low in staging gastric cancer.

Key words: Accuracy, Computer Tomography, Gastric, Colorectal.