Early FDG PET/CT Imaging as a Measure of Response in Patients With Non-Hodgkin Lymphoma on Lenalidomide

Inclusion Criteria: * Adult patients, at least 18 years of age * History of histologically confirmed NHL as assessed per medical record review. * At least one site of measurable disease (per RECIST 1.1) that is seen on CT, MRI, or FDG PET/CT. * Recommended to start lenalidomide. * Participants must be informed of the investigational nature of this study and provide written informed consent in accordance with institutional and federal guidelines prior to study-specific procedures. Exclusion Criteria: * Females who are pregnant or breast-feeding at the time of screening will not be eligible for this study. Female participants of child-bearing potential will have a urine or serum pregnancy test at the time of the screening visit. * Inability to tolerate imaging procedures in the opinion of the investigator or treating physician. * Serious or unstable medical or psychological conditions that, in the opinion of the investigator would compromise the subject's safety or successful participation in the study.