Current Evidence on PET Response Assessment to Immunotherapy in Lymphomas.

Response assessment in malignant lymphoma has progressively evolved in the last 20 years, leading to continuous adaptations to clinical requirements and technology improvements. The latest challenge in treatment evaluation is represented by immunomodulatory drugs, capable of stimulating response to cancer by unleashing the immune system of the host. Despite the consolidated consensus on the use of Deauville score and Lugano criteria for the assessment of first-line therapeutic regimens, during other lines of treatment and, particularly, during the course of immunotherapy, response parameters and clinical evidence appear less clear.