Radiation-associated head and neck sarcomas: spectrum of imaging findings

Sarcomas developing after radiation treatment for primary malignancies of the head and neck are often detected clinically when they are very aggressive. We reviewed the patient demographics and imaging findings in 21 patients with radiation-associated sarcomas (RAS) of the head and neck treated at our institution. Twenty-one RAS of the head and neck were retrospectively reviewed. The lesions were assessed for presence of a soft tissue mass, enhancement pattern, bone destruction, characteristics of tumor matrix, and FDG avidity. The RAS developed 4.5-25 years (mean 12.7 years) after irradiation. On both CT and MRI, all 21 lesions presented with a soft tissue mass. A variable imaging appearance was noted on CT, MR, and PET/CT, most, but not all, demonstrated aggressive features. At a median follow-up time of 19.1 months, 11 of the 21 patients had died from the sarcoma. RAS have variable imaging appearances. While most demonstrate aggressive features, some appear benign, which can lead to misdiagnosis. Head and neck radiologists, surgeons and oncologists who manage patients after radiation treatment should be aware of the wide range of clinical presentations and imaging features of RAS, because failure to diagnose can delay appropriate treatment.