Comparative Evaluation of Diagnostic Performances of Contrast Enhanced CT and 18-F FDG PET/CT in Staging of Lymphoma: Experience from a Tertiary Care Centre in North East India

Abstract

Background: Lymphoma is a malignancy arising from lymphocytes or lymphoblasts. Lymphoma can be restricted to the lymphatic system or can arise as extranodal disease. Lymphoma accounts for ~4% of all cancers. Prognosis depends not only on histological subtype and grade but also on stage, hence why imaging plays a pivotal role in treatment. The purpose of this study is to assess the diagnostic performance of contrast-enhanced computed tomography (CECT) and 2-[Fluorine-18] fluoro-2-deoxy-D-glucose positron emission tomography combined to computed tomography (18 F-FDG PET/CT) in the staging of lymphoma. Methods: Fifty five patients who were histologically proven as lymphoma, after giving written and informed consent were included in the study following inclusion and exclusion criteria. These patients underwent CECT and 18F-FDG PET/CT examination for staging of the disease. The lesions detected by each modality were categorized into true or false positives using reference standard and staging was done using Lugano criteria for staging of lymphoma. Further diagnostic performances of the two modalities were calculated using statistical analysis and compared. Results: Diagnostic performance of 18F-FDG PET/CT; sensitivity of 97.30%, specificity of 99.49%, and accuracy of 99.09% which was higher than diagnostic performance of CECT; sensitivity of 81.27%, specificity of 99.29%, and accuracy of around 96.03%. Staging was discordant in 21.81% of the patients when both the modalities were compared. Conclusion: Imaging with 18F-FDG PET/CT scan has a better diagnostic performance, represented by sensitivity and accuracy, than CECT scan in the staging of lymphoma in nodal as well as extra-nodal lesions. This leads to alteration of disease stage which in turn could markedly affect the decision of treatment regimens.

Keywords

CECT: contrast-enhanced computed tomography, 18F-FDG PET/CT: 2-[Fluorine-18] fluoro-2-deoxy-D-glucose positron emission tomography combined to computed tomography, HL: Hodgkin’s lymphoma, NHL: Non-Hodgkin’s lymphoma