PET-CT as the Preferred Imaging Modality for Extranodal Lymphoma Detection

Abstract

Background: Lymphoma frequently presents with extra-nodal involvement, which has critical implications for staging, prognosis, and treatment planning. Accurate detection of such disease sites remains a diagnostic challenge, particularly in resource-limited settings where conventional contrast-enhanced computed tomography (CECT) is often the primary modality.

Objective: This study aimed to compare the diagnostic performance of CECT and 18-fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET-CT) in identifying extra-nodal involvement among lymphoma patients.

Methods: A cross-sectional study was conducted at the Department of Radiology, Shaikh Zayed Hospital, Rahim Yar Khan, Pakistan, from February 2022 to February 2023, including 200 patients with confirmed lymphoma and clinical suspicion of extra-nodal spread. All patients underwent both CECT and PET-CT, and findings were validated against histopathology (where feasible) and clinical-radiological follow-up.

Results: PET-CT detected extra-nodal disease in 68.0% of patients compared to 59.0% with CECT. Sensitivity, specificity, PPV, and NPV for PET-CT were 92.7%, 100.0%, 100.0%, and 95.7%, respectively, outperforming CECT (74.3%, 88.6%, 90.6%, and 70.2%). PET-CT was particularly superior in detecting bone marrow and gastrointestinal involvement (p < 0.05).

Conclusion: These findings align with international evidence establishing PET-CT as the gold standard in lymphoma staging and emphasize its value in resource-constrained environments. Although barriers related to cost and availability persist, the integration of PET-CT into clinical practice may substantially improve diagnostic accuracy and patient outcomes in lymphoma management.