Stereotactic radiosurgery for the treatment of primary sarcomas and sarcoma metastases of the spine.

Objective: Spinal sarcomas pose unique treatment dilemmas because of the difficulty of achieving adequate surgical margins and/or delivering curative radiation doses (65 Gy) in close proximity to the spinal cord. This study used hypofractionated stereotactic radiosurgery (SRS) to deliver higher biologically effective doses to treat primary spinal sarcomas and spinal sarcoma metastases.

Methods: Twenty-four patients with spinal or paraspinal sarcomas entered an Institutional Review Board-approved registry trial to evaluate SRS efficacy. They were assessed at regular intervals for pain control, disease progression, and complications for a minimum of 12 months or until death.

Results: The median treatment dose for the spinal sarcoma lesions was 30 Gy at the 80% isodose in 3 fractions, with some variation based on tumor size, shape, and dose to adjacent critical structures. Seven patients were treated definitively; all had excellent pain relief and are alive with a mean follow-up period of 33 months. Two patients had complete tumor regression, 3 had partial regression, and 2 experienced recurrences and have been re-treated. Seven patients underwent resection and adjuvant SRS. One of 3 patients treated preoperatively had complete tumor regression, and none of the 4 patients treated postoperatively had a local recurrence with a mean follow-up period of 43.5 months. All 10 patients with sarcoma metastases to the spine (16 lesions) died, with a mean survival of 11.1 months from first spinal metastasis treatment. Complete pain relief was achieved in 8 patients, partial relief in 7 patients, and none in 1 patient. No patient developed radiation myelitis.

Conclusion: These preliminary results suggest that SRS may have a role in the definitive treatment of patients with primary spinal sarcomas who are deemed unresectable and as adjuvant treatment in those undergoing surgery and for palliation of sarcoma metastases.