Clinical results of carbon-ion radiotherapy with separation surgery for primary spine/paraspinal sarcomas

Purpose: To evaluate the clinical outcome of combination of carbon-ion radiotherapy with separation surgery (CIRT-SS) in patients with primary spinal/paraspinal sarcoma (PSPS) and epidural spinal cord compression (ESCC). Methods: CIRT-SS was performed in 11 consecutive patients. Patients treated in the primary and salvage settings were categorized into Group A (n = 8) and Group B (n = 3), respectively. Clinical results and imaging findings were collected, with a particular focus on ESCC grade, treatment-associated adverse events (AEs), and the locoregional control (LRC) rate and overall survival (OS). Results: The median follow-up period from the start of CIRT-SS was 25 months (7–57 months). ESCC was improved by SS in all cases. No patients exhibited radiation-induced myelopathy (RIM), but three developed Grade 3 vertebral compression fracture (VCF) during follow-up. Locoregional recurrences were observed in four patients [Group A: 1 (12.5%), Group B: 3 (100%)]. Over the entire follow-up period, three patients developed distant metastases and two patients died. The 2-year LRC rate and OS were 70% and 80%, respectively. Conclusion: CIRT-SS in the primary setting achieved acceptable LRC and OS without RIM in patients with PSPS and with ESCC. VCF was the most frequent AE associated with CIRT-SS.