Is Dose Volume a Better Predictor of Osteoradionecrosis Risk Than Total Dose for Patients Who Have Received Head and Neck Radiation?

PURPOSE

Oral and maxillofacial surgeons frequently encounter patients who require extractions following exposure to head and neck radiation, and they must assess the risk of extraction and consider alternatives such as deliberate root retention. The purpose of this study was to determine whether dose volume would be a better predictor for osteoradionecrosis (ORN) than total dose.

METHODS

This is a retrospective cohort study of patients diagnosed with ORN following head and neck radiation (administered between January 2006 and December 2018) and a comparison group selected based on site and dosage who did not develop ORN. The predictor variables were total radiation dose and mandibular dose volume, and the outcome variable was ORN occurrence. Covariates included age, sex, cancer stage and site, radiation therapy type, smoking status, alcohol use, adjuvant chemotherapy use, medical comorbidities, and concomitant tumor surgery. Logistic regression models were employed and area under receiver operating characteristic curve (AUROC) and model accuracy (Acc) were used to determine the better predictor.

RESULTS

A total of 56 patients were included in the study: 27 ORN positive (ORN+) and 29 matched controls who did not develop ORN (ORN-). Most patients were male (76.8%), considered smokers (78.6%), used alcohol (80.4%), were in stage IV (66.1%), received chemotherapy (75.0%), and received intensity modulated radiation therapy radiation (55.4%). The statistical models with V50 Gy (cc) and V65 Gy (cc) dosage variables exhibited greater predictability of ORN occurrence than total dose (AUROC: 0.90 vs 0.76 and model accuracy: 0.82 vs 0.75, respectively).

CONCLUSIONS

The results suggest that following head and neck radiation, dose volume may be a better predictor of ORN risk than total dose. This finding is significant, both for the oral and maxillofacial surgeon who is preoperatively assessing ORN risk following radiation exposure, and for the radiation oncologist striving to minimize the risk associated with their treatment.