DISEASE CHARACTERISTICS: Patients with any of the following diagnoses: Acute lymphocytic leukemia OR acute myeloid leukemia Failed to achieve complete remission (CR) with induction chemotherapy OR Relapsed within one year of initial CR OR Relapsed after autologous or allogeneic transplant OR Any subsequent relapse OR Refractory following relapse CR2 or more (phase I only) Blastic phase chronic myelogenous leukemia Prior therapy allowed Myelodysplastic syndrome, including the following: Refractory anemia with excess blasts (RAEB) OR RAEB in transformation (high intermediate or high risk only) Relapsed after transplant CR2 or more (phase I only) Non-Hodgkin's lymphoma OR Hodgkin's disease Newly diagnosed or in first relapse and failed to achieve CR or partial remission after induction or salvage chemotherapy OR Second or later relapse OR Relapsed after transplant No disease that can be encompassed in a standard radiation port No asymptomatic, minimally symptomatic, or low grade lymphoma Multiple myeloma Symptomatic, progressive, or recurrent disease after treatment with alkylating agents, high dose corticosteroids, or anthracyclines OR Relapsed following transplant Not eligible for autologous or allogeneic transplant A new classification scheme for adult non-Hodgkin's lymphoma has been adopted by PDQ. The terminology of "indolent" or "aggressive" lymphoma will replace the former terminology of "low", "intermediate", or "high" grade lymphoma. However, this protocol uses the former terminology.