Chondrosarcomas are slow-growing, malignant mesenchymal tumours characterized by the formation of cartilage by the tumour cells, high-grade malignant lesions with aggressive local behavior and metastatic potential. As chondrosarcomas grow slowly, with a relatively low fraction of dividing cells, and radiotherapy acts at dividing cells, chondrogenic tumors are considered relatively radiotherapy resistant. Radiotherapy can be considered in two situations: after incomplete resection, aiming at maximal local control (curative), and in situations where resection is not feasible or would cause unacceptable morbidity (palliative). For curative intentions, doses >60 Gy are required to achieve local control. However, application of this dose with conventional high-energy photon RT is often impossible in the vicinity of critical (neurological) structures, especially in chondrosarcomas arising in the skeleton. In this situation, postoperative RT is often indicated because these tumors or metastases are less accessible for radical resection. The clinical case of spinal chondrosarcoma demonstrates that disseminated not resectable chondrosarcomas, especially mesenchymal, which do not respond to the chemotherapy, may be considered for palliative radiotherapy with good local control results.
Keyword(s): chondrosarcoma; radiosensitivity; radiotherapy.
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