| Schedule | Constraint | Source |
|---|---|---|
| Conventional fractionation 70 Gy / 35 fx definitive · 60–66 Gy / 30–33 fx post-op | Mean ≤35 Gy, max ≤50 Gy | RTOG 0615 |
| Anterior globe (cornea, lens, iris): max ≤30 Gy; PRV max ≤35 Gy | DAHANCA 2025 |
Quoted from eviQ 5049, checked 2026-09-24. Full table with references →
The eyeballs, each sitting in its bony orbit, with the lens and cornea at the front and the retina lining the back.
The eyes focus light onto the retina at the back of the eye, which turns it into nerve signals for the brain.
High dose to the back of the eye can damage the retina and cause vision loss; dose to the front can cause dry eye, corneal injury and cataract. The globes matter when the target reaches the nasal cavity, sinuses, orbit or skull base — mainly nasopharynx and sinonasal cancers. In brain radiosurgery and glioma treatment they matter for targets near the orbit and the frontal lobe.
Brouwer 2015 splits each eyeball into two structures rather than one whole globe:
The EPTN 2018 atlas instead contours the cornea and the retina as thin separate structures (drawn with a 2–3 mm brush). Many protocols evaluate the whole globe, so check which structure your limit refers to. The lens is contoured as its own structure.
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.
The European Particle Therapy Network contouring atlas for brain organs at risk on CT and MRI, with anatomical descriptions and boundaries. Citation checked against Crossref.