Radiosurgery for the Treatment of Spinal Melanoma Metastases

Abstract

Background: The role of stereotactic radiosurgery in treating metastatic melanoma involving the spine has previously been limited. Conventional external beam radiotherapy lacks the precision to allow delivery of large single-fraction doses of radiation and simultaneously to limit the dose delivered to radiosensitive structures such as the spinal cord. This study evaluated the clinical efficacy of radiosurgery for the treatment of melanoma spinal metastases in 28 patients.Methods: Thirty-six melanoma spine metastases were treated with a single-session radiosurgery technique (1 cervical, 11 thoracic, 13 lumbar, and 11 sacral) with a follow-up period of 3–43 months (median 13 months). Tumor volume ranged from 4.1 to 153 cm³ (mean 47.6 cm³). Twenty-three of the 36 lesions had received prior external beam irradiation. Results: Maximum tumor dose was maintained at 17.5–25 Gy (mean 21.7 Gy). Spinal cord volume receiving >8 Gy ranged from 0.0 to 0.7 cm³ (mean 0.26 cm³); spinal canal volume at the cauda equina level receiving >8 Gy ranged from 0.0 to 3.5 cm³ (mean 0.98 cm³). No radiation-induced toxicity occurred during the follow-up period. Axial and radicular pain improved in 27 of 28 patients (96%) who were treated primarily for pain. Long-term tumor control was seen in 3 of 4 cases treated primarily for radiographic tumor progression. Two patients went on to require open surgical intervention for tumor progression resulting in neurological deficit. Conclusions: Spinal radiosurgery offers a therapeutic modality for the safe delivery of large dose fractions of radiation therapy in a single fraction for the management of spinal metastases in patients with advanced melanoma that are often poorly controlled with alternative conventional external beam radiation therapy, and is successful even in patients with previously irradiated lesions.

RTOG 0631 Phase II/III Study of Image-guided Stereotactic Radiosurgery for Localized Spine Metastases: Phase II Results

“…As such, this phase III clinical trial may provide additional biological evidence of a radiation dose response for pain control. Recent experience of single high dose spine SRS demonstrated a high pain response in patients with spine metastases; radioresistant tumors were equally responsive to a large fraction of radiosurgical dose (10,(17)(18)(19). Of note, the phase III component has been revised to allow the choice of two SRS doses, 16 Gy or 18 Gy, and to include radioresistant tumors such as melanoma, renal cell carcinoma, colon cancer and soft tissue tumors.…”

Stereotactic radiosurgery for spinal metastases with or without separation surgery

“…This limits the ability of cEBRT to deliver a cytotoxic dose to a tumor. 9,11,14,15,[22][23][24][25] Stereotactic radiosurgery (SRS), on the other hand, delivers high-dose radiation to spinal metastases while limiting irradiation of the spinal cord. 10,25,27 SRS has been shown through multiple studies to be accurate, safe, and effective in providing local tumor control and alleviating pain.…”

Spinal metastases: From conventional fractionated radiotherapy to single-dose SBRT

“…28 Similarly, long-term pain improvement and no acute or sub-acute neurological toxicities were reported in 77 lung cancer patients. 29 The majority of tumors in this series were non-small cell cancers (79/87, 91%), and 80% (70/87) received re-irradiation of lesions relapsing after previous conventional low dose radiotherapy. Patients with metastatic melanoma (36 lesions in 28 patients) also entertained excellent pain relief (96%), with a mean improvement of 7 points in a 10-point visual scale, and no recorded neurological toxicities.…”