(P143) Multisite Review of Twenty-Six Head and Neck Cancer Patients Who Have Developed Osteoradionecrosis: Location, Etiology, and Treatment

Rex Hoffman, MD, Daniel Copps, DDS, Earl Freymiller, MD, DDS, Sopirios Tetradis, DDS, PhD; Roy and Patricia Disney Family Cancer Center, Providence Saint Joseph Medical Center; private practice; UCLA School of Dentistry

INTRODUCTION: Osteoradionecrosis (ORN) is felt to be secondary to decreased blood flow through the inferior alveolar artery to the mandible. It has been well documented that if the dose of radiation exceeds a certain threshold, patients are at increased risk for this devastating treatment-related side effect. The effect that systemic therapy has on this altered blood flow is less clear. The medical and dental literature has conflicting reports that the rate of ORN increases or decreases when systemic therapy (chemotherapy or Erbitux) has been given with radiation. Here, the authors review 26 head and neck cancer patients who have developed ORN to see if systemic therapy increased their risk during radiation.

MATERIALS: A total of 26 head and neck cancer patients, treated at six different radiation oncology departments, were diagnosed with ORN by a single maxillofacial prosthodontist (DC), a dental radiologist, and a maxillofacial oral surgeon. ORN was defined as a condition of nonviable bone in the site of radiation injury. Diagnosis of ORN was made by both physical exam and radiographic imaging, which consisted of both a Panorex and a cone-beam computed tomography (CT) scan. For the purpose of this study, the patients’ records were reviewed, looking specifically at how radiation and systemic therapy had been delivered (induction vs concurrent), as well as what systemic agent(s) they received during radiation.

RESULTS: Median time to diagnosis of ORN after treatment by both physical exam and radiographic imaging was 77 months (range: 12–147 mo). Of the 26 patients, 5 had received radiation therapy alone, 7 had received induction chemotherapy followed by concurrent chemotherapy and radiation, and 14 had been treated with concurrent therapy (either Erbitux or platinum-based chemotherapy) and radiation. In each case, necrosis of the bone occurred in the posterior aspect of the mandible. None of the cases was iatrogenic. After the diagnosis was made, treatment consisted of either pharmacologic treatment or hyperbaric oxygen, followed by conservative oral surgery or hemimandibulectomy.

CONCLUSION: The medium time from the completion of treatment to diagnosis of ORN was over 6 years. All patients in this review developed ORN in the posterior aspect of the mandible. Neither the specific systemic agent (Erbitux or chemotherapy) nor the manner in which the agent was delivered (induction vs concurrent) appeared to increase the risk of ORN. It is hoped that having a better understanding as to the location, etiology, and treatment of ORN will help to minimize this potentially devastating complication for future generations of head and neck cancer patients.

Proceedings of the 97th Annual Meeting of the American Radium Society - americanradiumsociety.org