TABLE 2:

Differences in slopes between patients who were younger (≤6.8 years) or older (>6.8 years) at the start of craniospinal irradiation

CC Region	Age at CSI	Slope*	Significance†
Total	Younger	−24.0	0.27
	Older	−16.0
Rostrum	Younger	−0.6	0.24
	Older	1.0
Genu	Younger	−4.4	0.56
	Older	−2.4
Rostral body	Younger	−1.8	0.92
	Older	−2.0
Anterior midbody	Younger	−2.2	0.42
	Older	−1.2
Posterior midbody	Younger	−1.4	0.97
	Older	−1.4
Isthmus	Younger	−2.8	0.56
	Older	−2.0
Splenium	Younger	−13.4	0.09
	Older	−4.8

Note.—CC indicates corpus callosum; CSI, craniospinal irradiation.

^*Change in CC size per year since start of CSI (mm²).

^†Testing H₀: slope (reduced) = slope (conventional); P < .05, two-tailed test.