Current management of primary central nervous system lymphoma.

Primary central nervous cell lymphoma (PCNSL) is an uncommon neoplasm of the brain, leptomeninges, and rarely the spinal cord. Initially thought to be characteristically associated with congenital, iatrogenic, or acquired immunosuppression, PCNSL is now recognized with increasing frequency in immunocompetent individuals. The role of surgery is limited to establishing diagnosis, as PCNSL is often multifocal with a propensity to involve the subarachnoid space. A whole-brain radiation volume has empirically been used to adequately address the multifocal tumor frequently encountered at the time of PCNSL diagnosis. Despite high rates of response after whole-brain radiotherapy (WBRT), rapid recurrence is common and long-term survival is the exception. Chemotherapy alone or in combination with WBRT has more recently become the treatment of choice. Most effective regimens contain high-dose methotrexate and or other agents that are capable of penetrating the blood-brain barrier. High response rates and improved survival with the use of chemotherapy has led to treatment strategies that defer or eliminate WBRT in hopes of lessening the risk of neurotoxicity attributed to WBRT. Unfortunately, elimination of WBRT is also associated with a higher rate of relapse. Combined chemotherapy and WBRT regimens are now being explored that use lower total doses of radiation and altered fractionation schedules with the aim of maintaining high rates of tumor control while minimizing neurotoxicity. Pretreatment, multifactor prognostic indices have recently been described that may allow selection of treatment regimens that strike an appropriate balance of risk and benefit for the individual PCNSL patient.