 Because it is not known whether the use of ECP in the reduced intensity conditioning regimen was what caused the low incidence of GVHD, this research study will look at differences in getting GVHD based on whether you receive ECP. Half the patients in this research study will receive ECP as part of their reduced intensity-conditioning regimen and the other half will not. Patients will be randomized 50 chance you will receive ECP and 50 chance you will not. Both groups will receive pentostatin and reduced dose total body irradiation. The primary purpose of this research study is to look at the chance of developing serious GVHD within the first 100 days after transplant within each group. 