Phase II Study to Evaluate the Combination of Rituximab and DepoCyte® in the C5R Chemotherapy Protocol in Patients Between the Ages of 18 and 60 Years With Primary Cerebral Non-Hodgkin Lymphoma and Systemic Diffuse Large B-cell Lymphoma With Neuromeningeal Invasion at Diagnosis

Inclusion Criteria:

* Primary cerebral or oculocerebral NHL not previously treated with chemotherapy or radiotherapy and diffuse large B-cell lymphomas, with cerebral and / or neuromeningeal involvement at diagnosis.
* Diagnosis proved by histological or cytological examination of cerebral specimens, CSF or vitreous humour.
* Diffuse large cell CD20+ lymphoma.
* Men or women between the ages of 18 and 60 years.
* Presence of a measurable target to evaluate response.
* Negative serological tests for HIV, hepatitis B (except in cases of vaccination), hepatitis C.
* Life-expectancy ≥ 3 months
* Patient having given written consent to participate in this study.

Exclusion Criteria:

* CD20- lymphoma.
* History of indolent lymphoma, treated or untreated.
* Contraindication for one of the products used in polychemotherapy.
* Known hypersensitivity to mouse antibodies.
* Absence of measurable target to evaluate response.
* History of cancer in the 5 years prior to inclusion except for cutaneous basocellular carcinomas and non-invasive carcinomas of the neck of the uterus.
* Cardiac contraindication to treatment with anthracyclines or to hyperhydration:

SEVERE DISTURBANCE OF HEART RHYTHM VENTRICULAR EJECTION FRACTION BELOW 50% HISTORY OF RECENT MYOCARDIAL INFARCTION

* Previously known severe renal insufficiency and/or creatinaemia \>150 µM/L (apart from invasion of the kidneys by the lymphoma).
* Total bilirubin \>30 µmol/L, ASAT, ALAT \>2.5 times the upper normal value (apart from invasion of the liver by the lymphoma).
* Insufficient medullary reserve: PNL \< 1 G/L and platelets \<100 G/L (apart from invasion of the medulla by the lymphoma).
* History of organ transplantation or other causes of severe immunosuppression.
* Pregnant woman.
* Patient incapable of keeping to regular monitoring.