What chemotherapy protocol is effective for recurrent pcnsl? is eshap and/or ice a good option is mtx cannot be tolerated and wbrt already done?

PCNSL: The initial treatment for primary central nervous system lymphoma is methotexate and whole brain irradiation. The optimal treatment for this disease is unknown. There is much variation in clinical practice. Other agents used include Rituximab, procarbazine, vincristine, cytarabine, iosfamide in various combinations. All have some effect but all have toxicity. You need an oncology center.