Primary CNS lymphoma

Abstract

Primary central nervous system lymphoma (PCNSL), an uncommon tumor, is occurring with increasing frequency. Conventional therapy with corticosteroids and cranial radiotherapy (RT) usually gives a dramatic initial response, but median survival is only 10 to 18 months. Chemotherapy is more successful in comparable systemic lymphoma and has been employed for PCNSL at relapse, causing remission but not cure. Between June 1985 and June 1988, we prospectively staged 32 patients with PCNSL at Memorial Sloan-Kettering Cancer Center and treated 28 on a new protocol that combined chemotherapy and radiotherapy at diagnosis. None had occult systemic lymphoma, but 19% had ocular and 69% had definite or probable leptomeningeal lymphoma. There were no complications in 19 stereotactic biopsies, but 4/10 patients who had a complete resection suffered a severe postoperative deficit. Four patients received RT alone, and 28 received chemotherapy and cranial RT, 17 of whom (group A) received a combination regimen using pre-RT systemic (1 g/m²) and intra-Ommaya methotrexate (MTX), 4,000 cGy whole-brain RT with a 1,440 cGy boost, and 2 courses of post-RT high-dose cytosine arabinoside; 5 other patients received an identical regimen but with a decreased dose of MTX (200 mg/m²). Sixty-three percent of assessable patients had a response to MTX independent of corticosteroid and prior to RT. Eighteen of 26 (69%) assessable patients who received combined therapy are alive with a median follow-up of 25.4 months. Twelve of 16 (75%) assessable group A patients are alive in the same period. Chemotherapy-related toxicity was minimal, and no late toxicities have occurred to date. A vigorous multimodality approach to PCNSL was well tolerated, and survival is markedly improved over conventional therapy.