Table 3.

The correlation coefficient (r) and P value for sigmoid colon.

Relevant factors r, P	VHR-CTV	Vsub-sigmoid colon 1	Vsub-sigmoid colon 2	Vsub-sigmoid colon 3	Vsub-sigmoid colon 4	Vsub-sigmoid colon 5
$\text{r}({\text{D}}_{2\text{c}{\text{m}}^3}/{\text{D}}_{\text{prescription}})$	0.36**	0.85**	0.90**	0.85**	0.54**	0.57**
$P({\text{D}}_{2\text{c}{\text{m}}^3}/{\text{D}}_{\text{prescription}})$	0.010	<0.001	<0.001	<0.001	<0.001	<0.001

**When the confidence (double test) is less than 0.01, the correlation is significant.

Vsub-sigmoid colon, the volume of the sub-sigmoid colon.