Dosimetric distribution to the tooth-bearing regions of the mandible following intensity-modulated radiation therapy for base of tongue cancer.

Objectives: Osteoradionecrosis is a significant complication following head and neck radiotherapy. The purpose of this study was to determine the intensity-modulated radiation therapy (IMRT) dosages delivered to the tooth-bearing regions of the mandible.

Study Design: A total of 28 patients with base of tongue cancer with the following stages: T1-2/N2-3 (n = 10), T3-4/N2-3 (n = 10), and T1-4/N0 (n = 8), treated with IMRT, were included. Average mean and maximum doses were calculated for the anterior, premolar, and molar regions.

Results: Lower doses were seen in anterior bone with smaller tumors. Large tumors, regardless of laterality, resulted in high doses to the entire mandible, with anterior bone receiving more than 6000 cGy.

Conclusions: Tumor size is important in preradiation dental treatment planning. This information is important in planning pre- and postradiation dental extractions. Dosimetric analyses correlating mean and maximum point dose with clinical presentation and outcomes are needed to determine the best predictor of osteoradionecrosis risk.