Pulmonary metastasis from renal synovial sarcoma treated by stereotactic body radiotherapy: a case report and review of the literature.

Primary synovial sarcoma of kidney is an uncommon neoplasm, metastasizing most commonly to lung. Surgery and/or palliative chemotherapy for pulmonary metastases is commonly used to improve tumor control and survival. Stereotactic body radiotherapy (SBRT) is a relatively new approach to treat pulmonary metastasis, encouraged by the results of cranial and spinal stereotactic radiosurgery. The local control and toxicity profile of patients with pulmonary metastasis treated with SBRT are comparable to pulmonary metastatectomy. Furthermore, with advancement of imaging techniques, immobilization techniques, tumor-tracking techniques, and treatment planning and delivery system, SBRT can now be alternatively employed for the treatment of pulmonary metastasis as a comparable substitute to surgical resection.