High-Dose Chemotherapy Followed by Total-Body Irradiation and Peripheral Stem Cell Transplantation in Treating Patients With Chronic Lymphocytic Leukemia

DISEASE CHARACTERISTICS: Diagnostically proven intermediate, advanced, or high risk chronic lymphocytic leukemia of the B cells with marrow tumor reduced by prior therapy Marrow tumor content no greater than 30% of total nucleated cells Patients age 50 and under who have high risk disease are eligible Patients age 65 and under who have intermediate or high risk disease that has failed at least 1 therapy including an alkylating agent or fludarabine are eligible No history of transformation to aggressive lymphoma (Richter's syndrome)

PATIENT CHARACTERISTICS: Age: 17 to 65 Performance status: Karnofsky 70%-100% Life expectancy: Not severely limited by illness other than leukemia Hematopoietic: Absolute neutrophil count greater than 2,000/mm3 (no growth factor support) Platelet count greater than 120,000/mm3 (unless documented active autoimmune thrombocytopenia) Hemoglobin greater than 10 g/dL (unless documented active autoimmune anemia) No coexisting myelodysplasia Hepatic: Bilirubin no greater than 2.0 mg/dL Renal: Creatinine clearance at least 50 mL/min Cardiovascular: No cardiac disease that would limit ability to receive cytoreductive therapy and compromise survival Pulmonary: No pulmonary disease that would limit ability to receive cytoreductive therapy and compromise survival Other: No HIV antibody Not pregnant

PRIOR CONCURRENT THERAPY: See Disease Characteristics No prior radiation therapy to chest or abdomen greater than 2,000 Gy