Clinical Efficacy of Carbon Ion Radiotherapy for Unresectable Chondrosarcomas.

BACKGROUND: Carbon ion radiotherapy has precise dose distribution and high biological effectiveness and is likely a promising therapy for patients with sarcomas. We evaluated the outcomes of carbon ion radiotherapy in patients with unresectable chondrosarcomas.

PATIENTS AND METHODS: A retrospective analysis of 75 tumors in 73 patients treated with carbon ion radiotherapy was performed. There were 26 spinal, 38 pelvic, and 11 other types of tumors. Seventy conventional and five dedifferentiated chondrosarcomas were treated in 69 and four patients, respectively.

RESULTS: The median follow-up period was 49.4 (range=6.4-146.4) months. The 5-year local control, overall survival, and disease-free survival rates were 53%, 53%, and 34%, respectively. By multivariate analysis, tumor volume and histological grade were significantly related to overall and disease-free survival. Five patients required surgical intervention because of adverse events in the bones.

CONCLUSION: Carbon ion radiotherapy might be a treatment option for unresectable chondrosarcoma.