Background Lymphoma incorporates histologically variable cancers derived from the immune system cells. The distinctive feature of lymphoma is the rapid increase in size and number of lymph nodes and/or secondary lymphoid tissues. The aim of the work is to evaluate the accuracy of PET/CT vs CECT in the assessment of response to therapy in lymphoma patients: both early and late therapeutic response assessment. This retrospective study was conducted on 80 patients with different types of lymphoma recruited and enrolled from a university hospital. All 80 patients underwent pre-treatment, during the course of chemotherapy and at the end of planned treatment contrast-enhanced СT (СEСT) and PET-СT. Interpretation of the СEСT and the fusion images PET/СT each was done separately and comparison of the results was achieved. Results PET/CT and contrast-enhanced computed tomography were concurrent in results in 55% of cases during treatment and 75% at the end of treatment with CT sensitivity of 61.1%, specificity of 92.2%, and accuracy of 76.2% during treatment in comparison to 100% sensitivity and specificity of PET/CT. Sensitivity of CT at end of treatment was 57.5%, specificity 86.7%, and accuracy 71.6% as compared to 100% sensitivity and specificity of PET/CT. Conclusion PET/СT using 2-deoxy-2-[18F] fluoro-d-glucose is considered one of the best oncologic imaging modalities at the time being with valuable applications in lymphoma. It is very efficient with least possible pitfalls and false results compared to either of its components alone and to side by side reading of separately acquired PET and СT. PET/CT can detect both anatomical information as well as metabolical information providing more data and thus giving more accurate results than CECT. It is becoming а standard modality for lymphoma providing а new vision to management and treatment plan.

Background Lymphoma compromises а histologically heterogeneous group of cancers derived from the cells of the immune system. The hallmark of the disease is the enlargement and proliferation of lymph nodes or secondary lymphoid tissues. Aim of the Work to evaluate the role of Positron emission tomography in the assessment of response to therapy in lymphoma patients: in particular, a five-point scale (Deauville criteria), which can be employed for early- and late-therapeutic response assessment. Patients and Methods This cross sectional study was conducted on 20 Patients with different types of lymphoma recruited and enrolled from Ain Shams university hospital. Results PET/CT and Contrast enhanced computed tomography were concurrent in results in 55% of cases during treatment and 75 % at the end of treatment with CT sensitivity of 61.1%, specificity of 92.2% and accuracy of 76.2% during treatment in comparison to 100 % sensitivity and specificity of PET/CT.While sensitivity of CT at end of treatment is 57.5% with specificity of 86.7% and accuracy of 71.6%. Conclusion PET/СT using 2-deoxy-2[18F]fluoro-D-glucose is considered one of the best oncologic imaging modality at the time being with valuable applications in lymphoma.It is very efficient with least possible pitfalls and false results compared to either of its components alone and to side by side reading of separately acquired PET and СT. It is becoming а standard modality for lymphoma providing а new vision to management and treatment plan.