| Schedule | Constraint | Source |
|---|---|---|
| Conventional fractionation 70 Gy / 35 fx definitive · 60–66 Gy / 30–33 fx post-op | Avoid hotspots within the mandible | RTOG 0920 |
| V60 Gy <14% | Kubota 2021 |
Limiting intermediate-dose volumes may reduce osteoradionecrosis risk.
Quoted from eviQ 5049, checked 2026-09-24. Full table with references →
The lower jaw, from each temporomandibular joint down the ramus and along the body to the symphysis, carrying the lower teeth.
The lower jaw. It holds the lower teeth and moves for chewing, speaking and swallowing.
The main late risk is osteoradionecrosis — bone breakdown that can follow dental extraction or trauma in irradiated bone. The mandible often overlaps the target in oral cavity and oropharynx cancer, so the aim is usually to avoid hotspots within it and limit the volume at high dose, rather than a low mean. Dental assessment before treatment is part of the same risk reduction.
Brouwer 2015 contours the entire mandible bone, without the teeth, and recommends a CT bone window. RTOG 0920 likewise includes the entire bony mandible from the TMJ through the symphysis.
Consensus CT delineation guidelines for head and neck organs at risk from eight cooperative groups, with anatomical descriptions and example images. Citation checked against Crossref; content not yet reviewed by DoseLab.