Melphalan and Radiation Therapy Followed By Lenalidomide in Treating Patients Who Are Undergoing Autologous Stem Cell Transplant for Stage I, Stage II, or Stage III Multiple Myeloma

RATIONALE: Melphalan, a chemotherapeutic agent, has been found to be an effective treatment choice for destroying myeloma cells, especially when given at high (bone marrow ablative) doses. Total marrow irradiation (TMI)/ablative dose radiation therapy is another modality capable of destroying myeloma cells. Autologous peripheral blood/stem cell transplant (ASCT) given after either melphalan or following TMI (aimed at the bone marrow containing areas of the skeleton, the site of origin of myeloma cells) will shorten the duration/alleviate the severity of both melphalan and marrow irradiation-associated side effects. Lenalidomide, an effective agent on its own right for the treatment of myeloma, has been shown to further enhance the beneficial effects of autologous stem cell transplants when given as maintenance therapy. PURPOSE: This previously phase I trial established the maximum tolerated dose of TMI at 1600 cGy. The phase II part of this study is ongoing and is studying the effects of high-dose melphalan and ASCT, followed by TMI and a second ASCT, with subsequent maintenance lenalidomide. The study is conducted in patients with stages I-III myeloma, with specific emphasis on assessing complete and very good partial response rate conversions, progression-free and overall survival, and safety/feasibility of delivering the planned treatment regimen.