Parotid Gland Stem Cell Preservation during Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma: Dosimetric Analysis and Feasibility

Table 2

Tolerated doses for organs at risk.

Organs at risk	Dose limits
Brainstem	Dmax < 54 Gy, 1% vol < 60 Gy
Spinal cord	Dmax < 45 Gy, 1% vol < 50 Gy
Optic nerve	Dmax < 54 Gy
Eyeball	Dmax < 54 Gy
Lens	Dmax < 10 Gy
Temporal lobe	Dmax < 72 Gy
Temporomandibular joint	Dmax < 70 Gy
Parotid gland	Dmean < 26 Gy or 50% vol < 30 Gy
Submaxillary gland	>20 cm^3 vol received <20 Gy
Mandible	Dmax < 70 Gy
Middle ear	Dmean < 50 Gy
Throat	Dmean < 45 Gy
Oral cavity	Dmean < 40 Gy

D_max = maximum dose; D_mean = mean dose.