Intramedullary Spinal Cord Metastasis From Oligometastatic Melanoma of Unknown Primary Treated With Stereotactic Body Radiotherapy

Intramedullary spinal cord metastasis (ISCM) is an uncommon and challenging clinical entity with no established consensus regarding its optimal management.A 37-year-old female presented with left-sided facial numbness, right leg paresthesia with decreased temperature sensation, and right lower extremity weakness.Investigations demonstrated two intracranial lesions and an ISCM at T10 to T11.Biopsy of the intracranial lesion confirmed melanoma.The patient was treated with stereotactic body radiotherapy (SBRT) to a dose of 30 Gy in 5 fractions to the ISCM and stereotactic radiosurgery to a dose of 20 Gy in a single fraction to the intracranial metastases.The spinal cord dose received by a 0.035 cc volume was limited to less than or equal to 30 Gy.No spinal cord planning organ-at-risk volume was used.SBRT was followed by combination ipilimumab and nivolumab for four cycles, then maintenance nivolumab thereafter.At 25 months post-SBRT, the treated lesions decreased in size.There were no severe acute or late radiationrelated toxicities, and the patient remained fully ambulatory from presentation to last follow-up.