Radiation induced sarcomas of the head and neck following radiotherapy for nasopharyngeal 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 had tumours arising from the alveolar process of the maxilla, one from the nasal cavity, and one patient had a tumour at two sites, involving the external auditory canal and the uvula. Three of the four patients had large tumours 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, imaging has an important role in the pre-operative mapping of the extent of tumour. (C) 2000 The Royal College of Radiologists.