A Study of PET Adapted Therapy and Non-invasive Monitoring for Previously Untreated Limited Stage Diffuse Large B Cell Lymphoma

Inclusion Criteria: * Previously untreated limited stage non bulky DLBCL; defined as limited stage by routine staging criteria in lymphoma involving FDG-PET and bone marrow biopsies (the Lugano criteria)\[21\] * Patients with grade 3B follicular lymphoma and transformed indolent lymphoma are included * Ages ≥ 18 * Measurable disease, assessable by radiographic examination with FDG-PET showing involvement * Access to archived or fresh/frozen tumor biopsies * No uncontrolled medical comorbidities * Adequate cardiac function (EF \> or equal to 50%), no unstable angina * Adequate renal function (GFR \> 60) * Adequate liver function (liver function tests should be no greater than 2 x upper limit of normal) including normal bilirubin levels, no greater than 2 x upper limit of normal unless patient has a history of Gilbert's disease * Adequate marrow reserves as indicated by complete blood count in the judgment of the treating investigator Exclusion Criteria: * Pregnancy, positive serum HCG within 28 days of enrollment, or breast-feeding * Bulky disease greater than 10 cm in any dimension