Introduction
Radiation-associated sarcoma (RAS) is one of the most life-threatening complications associated with the treatment of malignant neoplasms. Because all RAS patients have a history of radiotherapy, there have been no effective treatment options when RAS is not completely resected.
Methods
We retrospectively reviewed 20 RAS patients, including 4 unresectable cases treated by carbon ion radiotherapy (CIRT).
Results
The primary diseases targeted by radiotherapy included malignant lymphoma (n=4), cervical cancer (n=3), pharyngeal cancer (n=3), breast cancer (n=2), lung cancer (n=1), rectal cancer (n=1), maxillary cancer (n=1), synovial sarcoma (n=1), and benign neoplasms (n=4). The histological diagnoses of RAS included osteosarcoma (n=8), leiomyosarcoma (n=3), undifferentiated pleomorphic sarcoma (n=3), rhabdomyosarcoma (n=1), angiosarcoma (n=1), malignant peripheral nerve sheath tumor (n=1), spindle cell sarcoma NOS (n=1), and sarcoma not further specified (n=2). The median survival time from the diagnosis of RAS was 26 months. Eleven patients underwent surgery. Five of these patients achieved a continuous disease free status or showed no evidence disease. Four patients underwent CIRT. One of these patients with leiomyosarcoma achieved a continuous disease free status, and the other patient with osteosarcoma achieved a partial response. On the other hand, 2 patients experienced Grade 3 toxicities that required surgical treatment.
Conclusion
RAS originates from various types of diseases that are treated by radiotherapy and shows diverse pathological features. Complete resection achieves a good prognosis. CIRT can be an effective and feasible option for unresectable RAS.