CDK4 and lymphoma: In the present study, we evaluated the role of [18F]-FDG PET/CT and compared the performance of response assessment by standard semi-quantitative criteria (EORTC and PERCIST) and by a visual scale (namely Deauville score) routinely used in lymphoma (16, 17) to predict PFS and OS in patients with metastatic breast cancer receiving therapy with CDK4/6i.