Table 1.

The initial dose‐volume constraints for primary plan.

Structure	Initial Dose‐volume Constraints	Relative Priority
${\text{PTV}}_{\mathrm{P}}$ a	${\mathrm{D}}_{100\%}$ b $\ge 99.5\%$ of the prescription dose	150
	${\mathrm{D}}_{98\%}\ge 100\%$ of the prescription dose	150
	${\mathrm{D}}_{2\%}\le 101\%$ of the prescription dose	150
	${\mathrm{D}}_{max}$ c $\le 102\%$ of the prescription dose	150
Rectum Wall	${\mathrm{V}}_{50\text{Gy}}$ d $\le 0\%$	100
	${\mathrm{V}}_{44\text{Gy}}\hspace{0.17em}\le 20\%$	100
	${\mathrm{V}}_{41\text{Gy}}\hspace{0.17em}\le 25\%$	100
	${\mathrm{V}}_{30\text{Gy}}\hspace{0.17em}\le 50\%$	100
Bladder	${\mathrm{V}}_{50\text{Gy}}\hspace{0.17em}\le 0\%$	100
	${\mathrm{V}}_{44\text{Gy}}\hspace{0.17em}\le 30\%$	100
	${\mathrm{V}}_{41\text{Gy}}\hspace{0.17em}\le 40\%$	100
	${\mathrm{V}}_{30\text{Gy}}\hspace{0.17em}\le 55\%$	100
Femoral Heads	${\mathrm{V}}_{34\text{Gy}}\hspace{0.17em}\le 0\%$	80
	${\mathrm{V}}_{30\text{Gy}}\hspace{0.17em}\le 10\%$	80
	${\mathrm{V}}_{23\text{Gy}}\hspace{0.17em}\le 50\%$	80
Body	${\mathrm{D}}_{max}\le 51.4\text{Gy}$	180

^a ${\text{PTV}}_{\mathrm{P}}$ is primary planning target volume.

^b ${\mathrm{D}}_{\mathrm{n}\%}$ means the dose received by the n% volume of the target volume.

^c ${\mathrm{D}}_{max}$ means the maximum dose received.

^d ${\mathrm{V}}_{\text{nGy}}$ means the percentage volume irradiated by n Gy or more of a certain structure.