Baykal, D

Abstract BACKGROUND Myxopapillary ependymomas (MPE) are slow-growing tumors of the spine typically involving the medullary conus and cauda equina. MPE is regularly managed with surgical resection with radiation therapy reserved for cases where gross total resection cannot be achieved. Management of inoperable cases represents a clinical challenge. No systemic therapy is approved for treatment of MPE. Addition of chemotherapy may improve outcomes for cases not amenable to resection. MATERIAL AND METHODS We report feasibility and preliminary efficacy of combination treatment with proton beam radiation therapy and temozolomide chemotherapy for a patient with large, unresectable MPE. RESULTS A 19-year-old female presented with one year of gradually worsening hip and back pain despite treatment with physical therapy. MRI Lumbar spine identified a destructive and expansile T2-heterogenous and hyperintense intraosseous mass (14 x 12 x 13 cm) with extraosseous expansion involving the sacrum, coccyx, and left SI joint with abnormal soft tissue enhancement extending along the posterior spine. No additional lesions were identified on neuro-axis imaging. Biopsy of the mass was consistent with a WHO grade 2 myxopapillary ependymoma. Standard treatment of care would include complete surgical resection. Unfortunately, this would require a morbid procedure in an en block fashion with immediate and permanent loss of bowel, bladder, sexual, and ambulatory function in a young patient whose primary symptom was pain and mild weakness. It was therefore elected to treat the patient in an unconventional approach and begin with proton beam radiation therapy (59.4 Gy in 33 fractions) with concurrent temozolomide followed by 6 cycles of adjuvant temozolomide. Mild clinical improvement and significant radiographic response were achieved (size reduced to 8 x 7 x 11 cm). CONCLUSION This case suggests a potential role for use of proton radiation therapy with concurrent and adjuvant temozolomide for management of myxopapillary ependymoma not amenable to surgical resection.