Table 1 Dose limits and complication probability of head and neck radiotherapy OARs

Brain stem

54 Gy

< 5%

Neuropathy or necrosis

Spinal cord

50 Gy

0.2%

Radiological spinal cord injury

Mandible

60–65 Gy

< 5%

Radioactive osteonecrosis

Optic nerve/optic chiasm

< 55 Gy

< 3%

Nerve damage

Eyes (single)

 < 35 Gy

–

Blindness

Parotid gland (single)

< 20 Gy

 < 20%

Parotid function chronically less than 25%

Submandibular gland

< 35 Gy

–

Xerostomia