ECOG performance status (PS) 0-3 (restricted to ECOG PS 0-2 if >= 70 years of age)Xx_NEWLINE_xXPatients must have an ECOG performance status of 0-2Xx_NEWLINE_xXPatients must have an ECOG performance status of 0 -2Xx_NEWLINE_xXSTEP II: ECOG performance status 0, 1, or 2 (PS 3 allowed if secondary to pain)Xx_NEWLINE_xXECOG performance status of 2 or greaterXx_NEWLINE_xXRE-REGISTRATION ELIGIBILITY CRITERIA (STEP 2): ECOG performance status 0-2Xx_NEWLINE_xXECOG performance score 0-3Xx_NEWLINE_xXECOG performance status 0-2Xx_NEWLINE_xXPatients must have an ECOG performance status of 0-2Xx_NEWLINE_xXCRITERIA FOR MAINTENANCE THERAPY-STEP 4: Patients must have an ECOG performance status of 0-3Xx_NEWLINE_xXEastern Cooperative Oncology Group (ECOG) performance status =< 2 (Karnofsky >= 60%) unless due to neurologic deficits caused by CNS lymphoma with the following exceptions: patients with ECOG performance status (PS) = 4 where neurologic deficits are unlikely to resolve with tumor resolution and may cause clinical management problems are excludedXx_NEWLINE_xXPerformance status of 0, 1 or 2 within 28 days prior to registrationXx_NEWLINE_xXECOG performance status 0 or 1Xx_NEWLINE_xXECOG performance status 0-2Xx_NEWLINE_xXPerformance status 0, 1 or 2Xx_NEWLINE_xXPatients with ECOG performance grade of 3 or 4Xx_NEWLINE_xX