RESIDUAL/RECURRENCE RATE AND FINDINGS IN POST OPERATIVE EVALUATION OF COLORECTAL CARCINOMA WITH THE ROLE OF CT AND PET-CT IN EARLY DETECTION

Abstract

Objectives: To find residuals/recurrence rates in colorectal carcinoma patients who have undergone surgery and to compare the effectiveness of CT and PET/CT in diagnosing the disease. Study Design: Cross-sectional diagnostic accuracy study. Place and Duration of Study: Radiology Department of Chaudhary Muhammad Akram Teaching and Research Hospital, Lahore, Pakistan, from 13 May to 13 August 2026 Methodology: 120 patients of colorectal adenocarcinoma aged 16-65 years were selected through a non-probability consecutive sampling technique. All of the patients underwent CT followed by FDG-PET/CT. Histopathology was used as a reference standard wherever feasible. Results of CT scan versus PET/CT scan were evaluated by calculating the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy of the diagnostic process. Results: The median age was recorded as 56 years (IQR=9.25). According to the histopathological findings, 44 (36.7%) subjects were diagnosed with recurrent/residual disease. CT provided sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of 93.2%, 77.6%, 70.7%, 95.2%, and 83.3%, respectively. PET/CT exhibited sensitivity of 90.9%, specificity of 92.1%, PPV of 87.0%, NPV of 94.6, and total diagnostic accuracy of 91.7%. Conclusion: Although the sensitivity of CT is slightly higher, we can observe the higher specificity and total accuracy of PET/CT, making it a better imaging technique used for recurrent or residual colorectal carcinoma diagnosis.