Study of Craniospinal Irradiation With Linac Based Volumetric Modulated Arc Therapy (VMAT) for Patients With Leptomeningeal Metastasis

Inclusion Criteria:

1. Solid tumor cancer primary with leptomeningeal metastases established radiographically and/or by CSF cytology
2. Candidate for radiation therapy for the treatment of leptomeningeal metastases
3. If patient had prior radiation, a treatment plan can be generated that will not exceed normal tissue tolerances
4. Patient must have reasonable systemic treatment options, as confirmed by their medical oncologist
5. Age ≥ 18 years old
6. Able to provide informed consent
7. Karnofsky Performance Scale (KPS) ≥ 60
8. Adequate hematologic baseline

   1. Hemoglobin \> 8g/dL
   2. Absolute neutrophil count \>1,000/mm3
   3. Platelet count \> 100,000/mm3
9. Female subjects must either be of

   1. Non-reproductive potential (over 60 years old, or without menses for at least 1 year without an alternative medical cause)
   2. Have history of hysterectomy, bilateral tubal ligation, or bilateral oophorectomy
   3. Must have negative serum/urine pregnancy test
   4. If of reproductive age, must practice effective contraceptive method

Exclusion Criteria:

1. Patient has multiple severe neurologic deficits per physician assessment
2. Patient has diffuse systemic disease without reasonable systemic therapy options
3. Patient is unable to undergo MRI brain and spine with gadolinium contrast
4. Prior radiation that would preclude development of a treatment plan that respects normal tissue constraints
5. Pregnant or lactating women
6. Prisoners