Combined Immunochemotherapy Followed By Reduced Dose Radiation Therapy (RT) for Patients With Newly Diagnosed Primary Central Nervous System Lymphoma

The purpose of this study is to find out if immunotherapy (rituximab) added to chemotherapy
is a safe treatment for primary central nervous system lymphoma (PCNSL). PCNSL is a rare
tumor. It is usually treated with chemotherapy and radiation. This combination prolongs
survival, but about half of patients relapse. We hope that the addition of rituximab will
improve the control of your tumor.

The second goal of this study is to assess a lower dose of brain radiation. Brain radiation
may cause memory loss or dementia. For patients over the age of 60, the risk of significant
memory loss is 80-90%. The risk for younger patients is smaller but less clear. In this,
study patients whose tumors are in remission after chemotherapy will be treated with a lower
dose of brain radiation. We hope that this lower dose will be less toxic. However, it is
also possible that using a lower dose of radiation will be less effective in controlling
your tumor.

Inclusion Criteria:

- All patients must have a histologic diagnosis of non-Hodgkin's lymphoma by brain
biopsy. Patients who have an inconclusive biopsy or who are not candidates for biopsy
may be eligible provided they have a typical cranial magnetic resonance imaging (MRI)
or computed tomography (CT) scan and meet at least one of the following two criteria:

- A positive cerebrospinal fluid (CSF) cytology for lymphoma or a monoclonal
lymphocyte population as defined by cell surface markers

- A biopsy of the vitreous or uvea demonstrating non-Hodgkin's lymphoma

- A typical MRI/CT scan for primary intracranial lymphoma is defined as the presence of
hypo, iso, or hyperdense parenchymal contrast-enhancing (usually homogeneously) mass
lesion(s)

- Patients must be HIV-1 negative

- Patients must have a normal or negative pre-treatment systemic evaluation including:

- A bone marrow aspirate and biopsy

- CT scans of the chest, abdomen and pelvis

- Patients must have adequate bone marrow function (defined as peripheral
leucocyte count > 4000 cells/mm3 and platelet count > 100,000 cells/mm3), liver
function (bilirubin < 2.0 mg and SGOT < 2 times upper limit of normal), and
adequate renal function (serum creatinine < 1.5 mg/dl or creatinine clearance >
50 cc/min/1.73M2)

- Men and women of reproductive potential must agree to use an acceptable method of
birth control during treatment and for six months after completion of treatment

Exclusion Criteria:

The following would exclude a patient from the study:

- Prior cranial irradiation

- Other active primary malignancy with the exception of basal cell carcinoma of the
skin and cervical carcinoma in situ

- Pre-existing immunodeficiency such as renal transplant recipient

- Prior treatment with chemotherapy for CNS lymphoma