Proton Craniospinal Radiation Therapy vs. Partial Photon Radiation Therapy for Leptomeningeal Metastasis From Solid Tumors

Inclusion criteria

• Patient with solid tumor malignancy with leptomeningeal metastases established radiographically and/or through CSF cytology
• Patients who are candidates for radiation therapy for the treatment of leptomeningeal metastases
• Patients of all ages
• KPS ≥ 60 for participants ≥ 16 years old, and Lansky ≥ 60 for participants < 16 years old
• For adult patient, the patient/ legally authorized representative is able to provide informed consent. For pediatric patient, a parent is able to provide informed consent.
• Adequate bone marrow function:

• Hemoglobin > 8g/dL
• Absolute neutrophil count >1,000/mm
• Platelet count > 100,000/mm
• Female subjects must either be of non-reproductive potential (i.e. pediatric patients, OR postmenopausal by history [≥ 60 years old, or with 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 at reproductive potential must agree to practice an effective contraceptive method.

Exclusion criteria

• Patient with multiple, serious major neurologic deficits per physician/investigator assessment 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.