Update on the use of FDG-PET/CT in malignant lymphoma.

This article aims to explain the current status of FDG-PET/CT in malignant lymphoma management by reviewing the new recommendations for evaluation, staging, and response assessment in patients with malignant lymphoma, published as the Lugano Classification in 2014. FDG-PET/CT was formally incorporated into standard staging for FDG-avid lymphoma in this new classification. Nearly all subtypes of malignant lymphoma are FDG-avid. In staging, the increased FDG uptake compatible with lymphoma is considered to represent involvement of lymphoma, regardless of size, and the FDG-avid lesion is potentially a good biopsy target. FDG-PET/CT is more sensitive than bone marrow biopsy in diffuse large B cell lymphoma (DLBCL) and Hodgkin lymphoma (HL). Location, size and FDG uptake, based on a 5 point scale (compared to hepatic uptake and mediastinal blood pool) for the residual lesion, constitute useful information for response assessment. Routine surveillance scans after remission are discouraged, especially for DLBCL and HL. Interim PET is regarded as a promising biomarker for stratifying treatments of malignant lymphoma, although its usefulness remains controversial.