Evaluation of Treatment Response of Lymphoma: Comparison Study Between PET CT Versus CECT

Malignant lymphoma is the commonest haematological malignant tumor globally. Aim of this work was to compare role of Contrast Enhanced Computed Tomography (CECT) and Positron Emission Tomography/CT (PET/CT) in treatment response assessment (TRA) of lymphoma. This study included 60 patients with histopathological confirmed lymphoma of different types. PET/CT scan was conducted based on the standard treatment protocols to TRA. Scanning was performed after at least one week since the last biopsy, two weeks since the last chemotherapy cycle, four weeks since last surgical procedure or three months after last radiotherapy session. The grading of FDG uptake at the most metabolically active site was expressed using the Deauville five-point scale. TRA was done by Lugano response criteria. CECT detected nodal affection in 36 cases and both nodal and extra nodal affection in 24cases. PET/CT detected nodal affection in 32cases and both nodal and extra nodal affection in 28 cases. CECT detected BM infiltration in 6cases, while PET-CT detected BM infiltration in 10cases. There were statistically significant differences regarding Duevinelle score in affected cases, before and after treatment. There was an increase in score 5 and decrease in score 1 and 2. There was statistically significant strong agreement between CT and PET-CT in the detection of affected sites within the affected lymph nodes (LNs). There was statistically significant mild agreement between CT and PET-CT in detecting BM infiltration. So, PET-CT demonstrated superior sensitivity (Sn) over CECT in the detection of BM infiltration and provided detailed assessment of disease activity through Deauville scoring.