Radiation induced sarcomas of the head and neck following radiotherapy fornasopharyngeal carcinoma

AIM: To report the radiological findings of radiation induced sarcomas (RIS ) in the head and neck following radiotherapy for nasopharyngeal carcinoma. MATERIALS AND METHODS: The clinical notes and radiological studies (MR n = 3, CT n = 4) of four patients were reviewed retrospectively. RESULTS: RIS developed 5 to 10 years following radiotherapy. Two patients h ad tumours arising from the alveolar process of the maxilla, one from the n asal cavity, and one patient had a tumour at two sites, involving the exter nal auditory canal and the uvula. Three of the four patients had large tumo urs at diagnosis with a 3.5-6 cm predominately homogeneous soft tissue mass , complete destruction of bone and extensive local invasion. One was small and localized to the nasal turbinate. Radiation osteitis was identified in two of the four (50%) patients. CONCLUSION: The site of RIS following radiotherapy for NPC is variable hut is invariably within the high dose zone of the radiotherapy. These sarcomas tend to present late with a large soft tissue mass. Radiation osteitis is not a constant feature. As surgery provides the only chance of cure, imagin g has an important role in the pre-operative mapping of the extent of tumou r. (C) 2000 The Royal College of Radiologists.