Table 1.

Plan constraints for key organs at risk and dose prescriptions for target volumes

Organ At Risk	Dose Constraint
Brainstem	$\text{Max}.\hspace{0.17em}\le \hspace{0.17em}54\hspace{0.17em}\text{Gy}$
Cord	$\text{Max}.\hspace{0.17em}\le \hspace{0.17em}45\hspace{0.17em}\text{Gy}$
Cord $+\hspace{0.17em}5\hspace{0.17em}\text{mm}$ margin	$\text{Max}.\hspace{0.17em}\le \hspace{0.17em}50\hspace{0.17em}\text{Gy}$
Optic chiasm	$\text{Max}.\hspace{0.17em}\le \hspace{0.17em}54\hspace{0.17em}\text{Gy}$
Optic nerves	$\text{Max}.\hspace{0.17em}\le \hspace{0.17em}54\hspace{0.17em}\text{Gy}$
Target Coverage
At least 95% of all PTVs should receive 100% of the prescribed dose ○ PTV70: 95% should receive 70 Gy ○ PTV63: 95% should receive 63 Gy ○ PTV59: 95% should receive 59.5 Gy At least 99% of all PTVs should receive 93% of the prescribed dose ○ PTV70: 99% should receive 65 Gy ○ PTV63: 99% should receive 58.6 Gy ○ PTV59: 99% should receive 55 Gy