Simultaneous bilateral stereotactic body radiation therapy of two inoperable centrally located pulmonary lesions in a patient with metastatic mesenchymal chondrosarcoma

The treatment recommendations for patients with inoperable residual intrapulmonary metastases from mesenchymal chondrosarcoma after completion of chemotherapy are sometimes controversial. We describe a case of simultaneous bilateral stereotactic body radiation therapy (SBRT) of two relatively large inoperable central pulmonary lesions in a patient with metastatic mesenchymal chondrosarcoma. The primary tumor was treated with complete surgery alone. Pulmonary failure with multiple lesions developed 5 years later. After systemic treatment with eight cycles of doxorubicin/ifosfamide, two relatively large bilateral centrally located metastases (4.7 and 2.1 cm) remained that were deemed inoperable. The metastases were treated by simultaneous bilateral SBRT. Because of the size and localization of the residual lesions, ablative SBRT protocols seemed unfavorable in respect to awaiting excessive pulmonary toxicity. We therefore used an individualized moderate dose prescription concept. Nevertheless SBRT resulted in excellent long-term outcome without any relevant toxicity.