Role of PET-CT in Characterization of Hepatic Lesions in Patients with Colorectal Cancers

Background: Colorectal cancer (CRC) remains a predominant contributor to cancer-related deaths globally, with the liver being the most frequent site for metastatic spread. Precise evaluation of hepatic lesions is critical for devising effective treatment strategies and determining prognosis. However, standard imaging techniques such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) occasionally fall short in reliably differentiating malignant from benign lesions. Objective: This investigation aimed to evaluate the utility of fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) in assessing liver lesions in CRC patients and to compare its diagnostic performance with that of conventional imaging modalities. Methods: This prospective, observational investigation was conducted involving 100 CRC patients presenting with hepatic focal lesions, all of whom underwent 18F-FDG PET-CT scanning. Lesions were assessed for metabolic activity via maximum standardized uptake values (SUVmax), and results were compared with findings from traditional imaging, histopathology, or clinical follow-up. Results: Among the 100 participants, 58% had malignant hepatic lesions, primarily metastatic deposits from colorectal cancer. Malignant lesions exhibited significantly elevated SUVmax values (mean 6.77 ± 2.10) as opposed to benign counterparts (mean 2.55 ± 2.09) (p < 0.001). Lesions exceeding 1 cm in size showed markedly higher FDG uptake (p < 0.001). The diagnostic metrics for 18F-FDG PET-CT revealed a sensitivity of 84.48%, specificity of 76.19%, and an overall accuracy of 81.00% in identifying malignant lesions. Conclusion: 18F-FDG PET-CT provides critical metabolic and anatomical insights that facilitate accurate distinction between benign and malignant liver lesions in CRC patients. As a complementary modality to conventional imaging, PET-CT significantly influences clinical decision-making by refining lesion characterization and informing therapeutic planning.