Incidence of osteoradionecrosis of the temporal bone.

Background: Osteoradionecrosis of the temporal bone is a serious, late complication of radiotherapy to the temporal bone region. The aim of this study was to determine the incidence, risk and protective factors relating to the development of osteoradionecrosis of the temporal bone.

Methods: This is a retrospective review of prospectively collected data. A single surgeon collated a database over a 10-year period regarding patients undergoing surgery and subsequent radiotherapy for head and neck malignancies. This was reviewed, and information pertaining to demographics, nature of disease, radiation treatment regime and complications including osteoradionecrosis was extracted. Statistical analysis was then completed independently.

Results: A total of seven patients from the cohort of 82 developed osteoradionecrosis of the temporal bone within the period of the data collection. This represents an incidence of 8.5% (95% confidence interval = 3.6-13.4%). All who developed osteoradionecrosis had a metastatic parotid squamous cell carcinoma treated operatively with subsequent radiotherapy. There were no statistically significant risks or prognostic factors identified. Mean duration of follow-up was 32 months.

Conclusion: The incidence of osteoradionecrosis of the temporal bone was 8.5% (95% confidence interval = 3.6-13.4%). Osteoradionecrosis of the temporal bone can present in excess of 10 years after treatment completion. This result may actually under -represent the true incidence of the complication. It has significant morbidity associated with its development and, occasionally, mortality. Those people undergoing radiotherapy to the parotid region may be at higher risk of osteoradionecrosis. A new classification system for osteoradionecrosis of the temporal bone has been proposed.