Study of Proton Radiation to the Brain and Spinal Cord for Patients With Leptomeningeal Metastases

Inclusion criteria

• Female subjects must either be of non-reproductive potential (i.e. post-menopausal by history: >/= 60 years old and no menses for 1> year without an alternative medical cause; OR history of hysterectomy, OR history of bilateral tubal ligation, OR history of bilateral oophorectomy) or must have a negative serum pregnancy test within 2 weeks prior to starting treatment.
• Patient with solid tumor malignancy with leptomeningeal metastases established radiographically and/or through CSF cytology.
• KPS ≥ 60.
• Age ≥ 10 years.
• For adult patient, the patient is able to provide informed consent. For pediatric patient, a parent is able to provide informed consent.
• Patient at reproductive potential must agree to practice an effective contraceptive method.
• Adequate bone marrow function:

• Hemoglobin ≥ 8g/dL
• Absolute neutrophil count ≥500/mm^3
• Platelet count ≥ 100,000/mm^3

Exclusion criteria

• Patient with multiple, serious major neurologic deficits including encephalopathy.
• Patient with extensive systemic disease and without reasonable systemic treatment options.
• Patient who is unable to undergo MRI brain and spine with gadolinium contrast.
• Previous radiotherapy to the intended treatment site that precludes developing a treatment plan that respects normal tissue tolerances.
• Pregnant or lactating women.