Objective: The purpose of this study was to determine dose delivered to individual mandibular tooth-bearing regions during adjuvant intensity-modulated radiotherapy for laryngeal cancers.
Study design: Twenty patients with laryngeal cancer treated with intensity-modulated radiotherapy were included. Individual mandibular tooth-borne areas were manually contoured. Average doses were calculated for individual teeth.
Results: Doses to individual teeth increased with more posterior location. Highest dose was observed for third molar (M3) (43.1 Gy; P < .001). Doses to molars and premolars correlated with T- and N-stage (P = .007; P < .001, respectively). For ipsilateral nodal disease, there was no difference between the doses to ipsilateral teeth and contralateral teeth. Only in N2 c tumors, dose was above our threshold for extraction for M3 only (51.5 Gy).
Conclusions: T- and N-stage drive dose to individual mandibular tooth-borne areas. With the exception of the posterior molars, particularly in node-positive patients, radiation exposure falls below the threshold reported for pre-RT tooth extractions (50 Gy). We concluded that a more conservative approach to prophylactic tooth extraction with a greater emphasis on dental management may be warranted for the prevention of osteoradionecrosis in patients with laryngeal cancer receiving adjuvant RT.
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