High-dose-rate interstitial brachytherapy as a suitable option for metastatic extraskeletal myxoid chondrosarcoma – a case report

We report on a patient with metastatic extraskeletal myxoid chondrosarcoma (EMC), who was treated with palliative high-dose-rate (HDR) interstitial brachytherapy (ISBT). The patient was an 87-year-old woman who underwent an amputation for a bulky tumor in her right ankle joint. EMC was histopathologically confirmed. She presented with a large right inguinal lymph node metastasis of EMC 16 months after surgery. Palliative HDR-ISBT (30 Gy/2 fractions in 1 day) for the right inguinal lymph node metastasis was administered to shorten treatment period. Additional HDR-ISBT (30 Gy/2 fractions in 1 day) was administered for the management of subsequent subcutaneous metastasis to the right breast and right popliteal fossa. HDR-ISBT provided significant long-term control of the recurrent tumor in all three sites, without severe acute and late toxicity. Thus, HDR-ISBT regimen of 30 Gy/2 fractions in 1 day can be a suitable option for both palliation and long-term local control for patients with metastatic EMC.