R-CDOP Combined With Intrathecal Methotrexate for DLBCL Patients With High-risk of CNS Relapse

This study is testing a treatment combination called R-CDOP plus spinal injections of a chemotherapy drug (methotrexate) for people newly diagnosed with an aggressive type of blood cancer called diffuse large B-cell lymphoma (DLBCL) who are at high risk of the cancer spreading to the brain or spinal cord. **You may be eligible if...** - You are between 18 and 75 years old - You have been newly diagnosed with DLBCL and have not received any treatment yet - Your cancer is considered high risk for spreading to the brain (based on a scoring system your doctor uses) - Your cancer involves certain body parts such as the testicles, breast, adrenal glands, kidneys, sinuses, or bone marrow - You are in generally good physical condition (able to carry out daily activities) - Your blood counts are within acceptable ranges **You may NOT be eligible if...** - You have already received treatment for your lymphoma - Your blood counts are too low - You have severe heart, liver, or kidney problems - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.