Concurrent Chemotherapy and Radiation Therapy for Newly Diagnosed Nasal NK Cell Lymphoma

Radiation Therapy: You will receive radiation therapy 5 days a week for 28 to 30 treatments (up to 6 weeks). You will receive a separate consent form that will describe this treatment and its risks in more detail. Study Visits During Radiation Therapy: Every week during radiation therapy: * You will have a physical exam. * Blood (about 1 teaspoon) will be drawn for routine tests. Chemotherapy Administration: You will start Cycle 1 of chemotherapy during your first week of radiation. Each cycle will be 21-days long (or longer if it takes longer for your blood cell counts to recover). You will receive up to 3 cycles of chemotherapy. On Days 1-3 of each cycle: * You will receive dexamethasone by vein over about 15 minutes. * You will receive etoposide by vein over 2 hours. * You will receive ifosfamide by vein over 3 hours. * Mesna is given to protect the bladder from side effects. You will receive mesna by vein as a non-stop infusion over 24 hours on Days 1-3 of each cycle. * On Day 1 only, you will receive carboplatin by vein over 30 minutes. Study Visits During Chemotherapy: On or before Day 1, on Day 15 of Cycle 2, and on Day 15 of Cycle 3, blood (about 2 teaspoons) will be drawn for routine tests. You may also have an EKG, if the doctor thinks it is needed. On or before Day 1 of Cycle 3: * You will have an EKG, if the doctor thinks it is needed. * Blood (about 2 teaspoons) will be drawn for routine tests. Length of Study: You may receive radiation and up to 3 cycles of chemotherapy. You will no longer be able to receive chemotherapy if the disease gets worse or intolerable side effects occur. Your participation on the study will be over after the end-of-study and follow-up visits. Follow-Up Visits: You will also have routine follow-up visits every 3 months for the 1st year, every 4 month during the 2nd year, and every 6 months during the 3rd-5th years. After that, you will have follow up visits 1 time every year. At these visits, the following tests and procedures will be performed: * Blood (about 2 teaspoons) will be drawn for routine tests. * Any skin lesions that you may have that are related to the tumor will be measured and photographed. If your doctor thinks it is needed, your MRI and PET/CT scans will be performed more or less often. If you leave the study early: * You will have CT, MRI, and PET/CT scans to check the status of the disease. * Any skin lesions that you may have that are related to the tumor will be measured and photographed. * You will have a physical exam. * Blood (about 2 teaspoons) will be drawn for routine tests.