Defining the role of ctDNA monitoring in a novel, risk stratified clinical trial for PTLD.

The purpose of this study is to find out if there is a benefit to giving rituximab with etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (R-EPOCH) in patients who have high-risk Bcell posttransplant lymphoproliferative disorder (PTLD), while those with low-risk disease will be spared of chemotherapy and treated with rituximab alone. Concurrently this study also wants to see how helpful a new blood test called circulating tumor DNA (ctDNA) is. This test has already helped doctors make better predictions and treatment decisions in other types of lymphoma. The goal is to demonstrate that ctDNA is a viable and informative tool in treating PTLD with the hope that in the future it may be used to individualize treatment for patients with PTLD in a way that limits treatment toxicity without losing the effectiveness of the treatment plan.

Are you Eligible? (Inclusion Criteria)

• Are you 15 years or older? - Do you not have lymphoma (a type of cancer, is affecting a certain part of the body) affecting their brain or spinal cord? - Do you have Post-Transplant Lymphoproliferative Disorder (PTLD)?