Table 1.

Clinical goals for organ at risk

Structure	Clinical goals (Gy RBE) protons (Gy) photons
Brainstem	D1% ≤60
Chiasm	D1% ≤55
Spinal cord	D1% ≤55
Optic nerve	D1% ≤55
Temporal lobs	D1% ≤72
Cochlea	Dmean≤35

RBE: Relative biological effectiveness