How do you decide on the modality of consolidative treatment after a CR in primary CNS lymphoma patients treated with a high-dose methotrexate regimen?   

Unless there are contraindications to autologous transplant I favor consolidation with autologous transplant.  The long term complications of whole brain XRT include significant neurocognitive deficits.  These approaches are rough equal with regards to efficacy.

Another consolidative option is non-myeloablative chemotherapy with etoposide plus cytarabine (EA) based on the CALGB 50202 trial (Rubenstein et al., JCO 2013) using MTR induction, followed by consolidation EA. In that trial, the 2-year time to progression was 59%, and for patients who completed con...