FDG PET/CT Response Assessment Criteria for Patients with Hodgkin’s and Non-Hodgkin’s Lymphoma at End of Therapy: A Multiparametric Approach

Purpose Based on the International Harmonization Project (IHP) criteria, positron emission tomography (PET) response assessment of residual nodal masses in patients with lymphoma after completion of therapy is performed visually using mediastinal blood pool as the reference. The primary objective of this study was to define the optimal reference for PET response assessment. Secondary aim was to assess if morphological criteria on computed tomography (CT) may improve performance of PET. Methods This institutional review board approved retrospective study included 137 patients, with Hodgkin’s ( n = 43) or non-Hodgkin’s lymphoma ( n = 94) assessed for residual masses ( n = 180) after completion of therapy with pathology and clinical and imaging surveillance data (mean, 19 months) as the standard of reference. Two readers independently assessed response by IHP and Deauville criteria. The addition of morphological parameters on CT was assessed in relation to therapy response. Results Based on the standard of reference, 36 patients (26.3 %) had residual lymphoma. For IHP and Deauville criteria, sensitivity, specificity and accuracy were 97.2 %, 97.2 % ( p = 1); 79.2 %, 92.1 % ( p