Radiation-specific Automated Dosimetric dental, Mandible, and maxilla Annotation for Predicting Periodontal Problems (RADMAP): A semi-automated tool for dosimetric oral risk communication and osteoradionecrosis assessment.

PURPOSE/

OBJECTIVES

Osteoradionecrosis of the jaw (ORN) is a severe complication of head and neck cancer (HNC) radiotherapy (RT), significantly impacting patient quality of life. Current dose assessment relies on whole-mandible dosimetry, limiting personalized, tooth-specific region risk evaluation. The lack of standardized methods to document and analyze dose distributions to tooth-bearing regions further hampers dental and maxillofacial decision-making. This study develops and evaluates RADMAP, a (semi-)automated tool for segmenting tooth-based jaw regions, enabling patient- and tooth-specific radiation dose mapping to improve dental dose reporting and ORN risk assessment.

METHODS AND MATERIALS: A total of 736 tooth locations from 23 HNC patients treated with definitive RT were analyzed, including 11 who developed ORN. The RADMAP tool applies an angular ray-based algorithm to automatically segment the mandible and maxilla into 32 tooth-specific jaw regions, with optional manual refinement (semi-automated), outputting radiation dose mapping in both tabular and odontogram formats. Mean dose values from manually contoured tooth roots were compared with RADMAP-segmented alveolar regions (fully and semi-automated). Interobserver agreement among six users was evaluated. Whole-mandible, manual tooth, and tooth-based jaw segment (alveolar and basal) doses were compared between regions with and without ORN development.

RESULTS

Mean dose correlation between RADMAP-segmented alveolar jaw regions and manually segmented tooth roots was high for both fully and semi-automated approaches (R2 = 0.98, p<0.0001), demonstrating accurate dose estimation. Interobserver agreement showed 95% limits of ±2.9 Gy for mandibular alveolar segments, confirming reproducibility. Tooth-based jaw segments showed a significant differentiation in radiation dose for the ORN-positive versus ORN-negative sites (difference in mean dose (DIM): 12.4 ±3.7 Gy, p=0.0008), which was not seen when considering the whole-mandible dose (DIM=6.2 ±4.3 Gy, p=0.17), demonstrating RADMAP's promise for improved ORN risk assessment.

CONCLUSION

RADMAP enables accurate, tooth-specific dose mapping of the mandible and maxilla, and potential improved ORN risk differentiation beyond whole-mandible dosimetry. Tooth-based dose reporting can personalize treatment, enhance multidisciplinary communication, and support prevention of radiation-related orodental sequelae.