• Age \> 18 years old. (The indication for this technique is controversial in skeletally immature patients.)

• Histologic diagnosis of solid malignant tumor (not one of the more radiosensitive histologic subtypes, see Exclusion Criteria), including but not limited to non-small cell lung cancer, breast, prostate, renal cell, melanoma, gastrointestinal, sarcoma, thyroid, head and neck primary, and unknown primary tumors.

• Quantification of the degree of epidural spinal cord compression as grade 1C, 2, or 3 by MRI, with and without contrast sequences. Axial T2 sequence is encouraged but not required.

• The vertebral body site to be treated must be located from T2 to L1

• No more than 3 contiguous or dis-contiguous vertebral levels involved with metastasis in the spine to be irradiated in a single session or 3 sessions.

• Motor strength ≥4 out of 5 in extremity or extremities affected by the level of the spinal cord compression (see section 4 for grading method).

• ECOG performance status \<2 or Karnofsky performance status (KPS) \>50

• Life expectancy \>3 months.

• Inoperable disease because of patient refusal, neurosurgical evaluation, or any other medical reasons.

• Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) before study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately.

• Prior conventional radiation to the same site is allowed as long as there is a greater than 3 months interval.

• Signed informed consent.