Beginning 2-4 weeks after apheresis, patients receive a preparative regimen comprising cyclophosphamide IV over 2 hours on days -5 and -4 and fractionated total body irradiation twice a day over 6-10 hours on days -3 to -1. Patients undergo peripheral blood stem cell transplantation on day 0. Patients receive G-CSF SC beginning on day 1 and continuing until blood counts recover.