 Tumour assessment clinical examination, laboratory tests, abdominal and chest CT scan for PCNSL only at baseline, - PET scan for DLBCL, - brain MRI and CSF examination and ophthalmic examination for PCNSL, - bone marrow examination except for PCNSL will be performed at baseline, and then every 2 months during the first 6 months of treatment, and every 3 months thereafter until disease progression or up to 6 months after study treatment stop. 