Table 2. Impact of brainstem dose–volume on functional recovery of patients with infratentorial ependymoma treated with postoperative irradiation.

		12 month follow-up				24 month follow-up				60 month follow-up
Dose factor	Group response	n patients	Mean irradiated brainstem volume ± SE (ml)	% volume of irradiated brainstem ± SE%	p value	n patients	Mean irradiated brainstem volume ± SE (ml)	% volume of irradiated brainstem ± SE%	p value	n patients	Mean irradiated brainstem volume ± SE (ml)	% volume of irradiated brainstem ± SE%	p value
Volume	FR or NL (+)	23	15.7 ± 0.8		0.42	24	15.3 ± 1.0		0.97	27	15.4 ± 0.9		0.78
>54 Gy	FR or NL (-)	39	14.8 ± 0.7			33	15.4 ± 0.7			23	15.1 ± 0.8
Volume	FR or NL (+)	23	14.6 ± 1.1		0.32	24	13.6 ± 1.4		0.96	27	13.4 ± 1.3		0.99
>56 Gy	FR or NL (-)	39	13.0 ± 1.0			33	13.7 ± 1.1			23	13.4 ± 1.3
Volume	FR or NL (+)	23	12.9 ± 1.3		0.66	24	12 ± 1.5		0.60	27	11.8 ± 1.4		0.64
>58 Gy	FR or NL (-)	39	12.2 ± 1.0			33	13 ± 1.0			23	12.8 ± 1.3
Volume	FR or NL (+)	23	9.4 ±1.4		0.17	24	8.7 ± 1.5		0.54	27	7.8 ± 1.4		0.88
>60 Gy	FR or NL (-)	39	7.0 ± 1.0			33	7.6 ± 1.1			23	7.5 ± 1.3
% volume	FR or NL (+)	23		78.5 ± 2.4	0.63	24		75.7 ± 3.3	0.10	27		76.4 ± 3.0	0.19
>54 Gy	FR or NL (-)	39		80.5 ± 2.8		33		82.6 ± 2.6		23		82.5 ± 3.3
% volume	FR or NL (+)	23		72.3 ± 4.2	0.68	24		65.8 ± 5.8	0.38	27		64.8 ± 5.6	0.39
>56 Gy	FR or NL (-)	39		69.2 ± 5.2		33		72.8 ± 5.2		23		72.3 ± 6.6
% volume	FR or NL (+)	23		63.8 ± 5.6	0.86	24		57.9 ± 6.5	0.19	27		56.7 ± 6.2	0.18
>58Gy	FR or NL (-)	39		65.2 ± 5.1		33		68.9 ± 5.2		23		69 ± 6.5
% volume	FR or NL (+)	23		45.4 ± 6.3	0.37	24		42.2 ± 6.6	0.87	27		37.1 ± 6.3	0.70
>60Gy	FR or NL (-)	39		37.8 ± 5.4		33		40.7 ± 5.8		23		40.8 ±7.1