Predicting radiotherapy (RT) tooth dose guides pre-RT dental management, reducing osteoradionecrosis (ORN) risk through informed extraction or treatment adjustments. This study evaluated the mean radiation dose to individual teeth for head and neck cancer (HNC) patients receiving external beam RT at the South West Wales Cancer Centre (SWWCC), to guide pre-emptive tooth extraction.

A retrospective analysis was conducted on 158 HNC RT patients treated over a 2-year period. Patients with subsites containing ≤10 patients were excluded, and larynx cases were analysed separately before exclusion due to low ORN risk, leaving 107 patients in the final analysis. Teeth were outlined using MedCom ProSoma v4.2, and treatment plans were generated with Philips Pinnacle v16.2 using volumetric arc therapy (VMAT), without dental dose optimisation. Mean doses were reported per tooth and categorised by site, staging and tooth position, with mean and standard deviations calculated. ORN risk was defined as medium (≥40Gy) and high (≥50Gy).

Larynx patients received low mean doses (<25Gy), supporting their exclusion. Base of tongue (BoT) cases showed a dose ≥40Gy for lower ipsilateral molars in T4. Oral cavity diagnosis had the highest ORN risk, with most teeth ≥40Gy in T2+ cases and ≥50Gy in later cancer staging. The oropharynx showed some higher risk doses for T4-staging. T-tests confirmed significant dose differences between upper and lower teeth.

This study provides a site-specific indicative guide for pre-RT tooth extraction based on likely dose exposure, to guide pre-radiation dental management strategies and plan optimisation decisions to reduce ORN risk.