Approximately 1-3 weeks later, patients in both cohorts who demonstrate adequate uptake of the first diagnostic dose of holmium Ho 166 DOTMP into the bone marrow then receive therapeutic holmium Ho 166 DOTMP IV over 15 minutes once between days -13 to -10 followed by melphalan IV over 20-30 minutes once between days -10 to -1. Patients undergo autologous peripheral blood stem cell transplantation on day 0.