Gamma knife stereotactic radiosurgery as an effective tool in primary CNS lymphoma: Evaluation of stereotactic radiosurgery and methotrexate treatment in a prospective and observational clinical research study

Background: Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal non-Hodgkin lymphoma that accounts for ∼4% of newly diagnosed central nervous system (CNS) tumours. The objective of this study was to analyse the epidemiology, incidence, and outcome of these rare tumours. Methods: Primary brain and CNS lymphoma cases were identified from the Surveillance, Epidemiology, and End Results (SEER) research data sets for the years 1980–2008 for analysis of trends in incidence and survival. SEER*Stat v. 7.0.4 software was used to analyse the data. Results: The overall incidence rate of PCNSL was 0.47 per 100 000 person-years. The incidence was significantly higher in males compared with females, blacks aged 0–49 years at diagnosis compared with whites, and whites aged 50 years and older at diagnosis compared with blacks. After a significant decline in incidence between 1995 and 1999, incidence rates rose slightly; those aged 75+ years at diagnosis had the most dramatic increase in incidence rates over time. Five-year survival rates were significantly higher in whites compared with blacks aged 0–49 years at diagnosis, but was primarily driven by white women aged 0–49 years. Conclusion: There is an increase in incidence of PCNSL in the elderly, and elderly blacks have lower incidence compared with white population. Survival remains poor and is negatively dominated by factors associated with HIV infection and advanced age.

The management of primary CNS lymphoma is one of the most controversial topics in neuro-oncology because of the complexity of the disease and the very few controlled studies available. In 2013, the European Association of Neuro-Oncology created a multidisciplinary task force to establish evidence-based guidelines for immunocompetent adults with primary CNS lymphoma. In this Review, we present these guidelines, which provide consensus considerations and recommendations for diagnosis, assessment, staging, and treatment of primary CNS lymphoma. Specifically, we address aspects of care related to surgery, systemic and intrathecal chemotherapy, intensive chemotherapy with autologous stem-cell transplantation, radiotherapy, intraocular manifestations, and management of elderly patients. The guidelines should aid clinicians in their daily practice and decision making, and serve as a basis for future investigations in neuro-oncology.