Radiation Therapy in Relapsed or Refractory Non-Hodgkin's Lymphoma Who Have Undergone Stem Cell Transplantation

OBJECTIVES: * Compare the 3-year progression-free survival of patients with relapsed or refractory aggressive non-Hodgkin's lymphoma treated with high-dose chemotherapy and autologous hematopoietic stem cell transplantation with or without involved-field radiotherapy. * Compare the overall survival of patients treated with these regimens. * Compare 3-year progression-free disease within and outside radiotherapy fields in patients treated with these regimens. * Compare quality of life of patients treated with these regimens. * Compare the toxic effects of these regimens in these patients. OUTLINE: This is a randomized, multicenter study. Patients are stratified according to response to pre-salvage chemotherapy (primary refractory disease vs relapse), response to post-salvage chemotherapy (complete/unconfirmed complete vs partial), and participating center. Within 6-8 weeks after completion of autologous hematopoietic stem cell transplantation, patients are randomized to 1 of 2 treatment arms. * Arm I: Patients undergo involved-field radiotherapy (IFRT) 5 days a week for 3-5 weeks in the absence of unacceptable toxicity. * Arm II: Patients undergo observation only. Quality of life in arm I is assessed at baseline, on day 1 of IFRT, at weeks 2 and 4 during IFRT, at 1 month, 4 months, every 3 months for 2 years, every 6 months for 1 year, and then annually for 2 years. Quality of life in arm II is assessed at baseline, 1 month, 2 months, every 3 months for 2 years, every 6 months for 1 year, and then annually for 2 years. Patients are followed at 1 month, every 3 months for 2 years, every 6 months for 1 year, and then annually for 2 years. PROJECTED ACCRUAL: A total of 230 patients (115 per treatment arm) will be accrued for this study within 4.2 years.