Osteoradionecrosis in patients with salivary gland malignancies

• Risk of ORN after radiotherapy for salivary gland malignancy was 4% (95% CI: 1.6–8.2%).
• ORN only occurred in patients treated with primary disease in the major glands or minor glands arising in the oral cavity.
• Many cases of ORN developed after traumatic injury to the bone.

SummaryPurposeThe present study was undertaken to evaluate osteoradionecrosis (ORN) in patients with salivary gland malignancies (SGM) after treatment with radiation therapy.Materials and methodsThe medical records of 172 patients treated with radiation therapy for SGM during a 12-year period (August 2001 to November 2013) were reviewed. Incidence, time to event, staging and management of ORN were analyzed.ResultsOf the 172 patients, 7 patients (4%) developed ORN (median latency: 19 months, range: 4–72 months). Of those 7 patients, 4 required major surgery, 1 required hyperbaric oxygen therapy (HBO), one required minor debridement, and one required conservative management. Total prescribed radiation dose varied from 50 Gy (1 case) to 70 Gy (1 case) among those patients who developed ORN, and radiotherapy was delivered postoperatively after osseous resection in 4 of 7 cases. Three of the 7 cases of ORN occurred after traumatic injury to the bone. Of the 7 patients who developed ORN, 3 had SGM of the major glands, 3 had other sites of the oral cavity, and 1 had a sinonasal location.ConclusionWhile the rate of ORN after radiotherapy for SGM was somewhat lower (4%) than previously published data on patients with squamous cell carcinomas of the head and neck treated with radiation therapy (8–14%), ORN necessitating major surgery remains a clinically significant, possible late effect of radiotherapy in SGM survivors. Location of SGM is very important, with cases that developed ORN disproportionally having primary disease arising in the oral cavity.