Temporal Bone Osteoradionecrosis After Surgery and Radiotherapy for Malignant Parotid Tumors

OBJECTIVE: To assess the incidence of osteoradionecrosis (ORN) of the temporal bone after surgery with radiotherapy for malignant parotid tumors. SETTING: A tertiary care, academic medical center. PATIENTS: All patients who underwent surgical resection with postoperative radiotherapy (RT) for a malignant parotid tumor between July 1988 and July 2007. INTERVENTIONS: A retrospective chart analysis to determine the extent of surgery, the RT parameters, and the incidence of ORN of the temporal bone. MAIN OUTCOME MEASURES: The incidence of ORN in 3 subgroups of patients. RESULTS: The 221 patients with malignant parotid tumors who underwent surgical resection with postoperative RT were divided into groups 1, parotidectomy only; 2, parotidectomy with mastoidectomy; and 3, parotidectomy with subtotal petrosectomy. The overall incidence of temporal bone ORN in group 1 was 2 (2%) of 106; in group 2, 8 (13%) of 64; and in group 3, 0 (0%) of 51. CONCLUSION: The incidence of temporal bone ORN is higher after mastoidectomy for facial nerve identification or resection in patients undergoing parotidectomy with postoperative radiotherapy. Oversew of the ear canal with mastoid obliteration should be considered in this subgroup of patients to avoid this long-term complication of radiotherapy used in the treatment of malignant parotid tumors.