Table 3.

Overview of the dose volume analysis on the EQD2 accumulated plans

		EQD2 of accumulated photon reirradiation plan (stdv)	EQD2 of accumulated proton reirradiation plan (stdv)	Significance according to Wilcoxon signed-ranks test
Brain–brainstem	Max dose	105.1 (±20.4)	105.3 (±19.9)	not significant
	Mean dose	15.5 (±6.8)	13.7 (±5.8)	p < 0.01
Brainstem	Max dose	24.3 (±30.0)	21.7 (±31.8)	not significant
	Mean dose	8.2 (±10.0)	7.1 (±9.4)	p < 0.01
Chiasm	Max dose	20.9 (±24.4)	18.5 (±23.2)	p < 0.01
	Mean dose	13.2 (±15.9)	11.0 (±13.5)	p < 0.01
Optic nerve left	Max dose	17.6 (±22.6)	16.0 (±21.8)	p < 0.01
	Mean dose	10.8 (±14.4)	9.9 (±13.9)	p < 0.01
Optic nerve right	Max dose	18.8 (±23.8)	18.3 (±24.7)	not significant
	Mean dose	13.0 (±18.4)	12.3 (±18.2)	p < 0.01
Hippocampus left	Max dose	19.3 (±20.1)	16.2 (±19.6)	p < 0.01
	Mean dose	9.5 (±11.7)	7.5 (±11.0)	p < 0.01
Hippocampus right	Max dose	24.9 (±33.4)	23.4 (±33.6)	p < 0.05
	Mean dose	14.8 (±20.7)	14.7 (±24.4)	not significant
Pituitary gland	Max dose	19.5 (±24.8)	17.6 (±23.6)	p < 0.01
	Mean dose	15.1 (±20.6)	13.9 (±20.2)	p < 0.01
Cochlea left	Max dose	10.1 (±16.8)	9.3 (±16.8)	p < 0.01
	Mean dose	8.4 (±14.1)	7.6 (±14.0)	p < 0.01
Cochlea right	Max dose	13.0 (±22.1)	12.7 (±23.7)	not significant
	Mean dose	11.3 (±20.4)	10.7 (±20.8)	not significant
	Volume in ccm (stdv)
V100		5.4 (±8.5)	8.0 (±9.5)	p < 0.05
V90		25.4 (±33.4)	30.1 (±40.7)	p < 0.05
V70		51.2 (±69.5)	62.6 (±65.6)	p < 0.05
		Integral dose in Gy (stdv) to the single reirradiation plans
	Photons	Protons
Total integral dose		12.4 (±12.7)	6.4 (±6.0)	p < 0.01
Dose to brain-PTV		6.4 (±6.2)	2.7 (±2.5)	p < 0.01
		Conformity index of the reirradiation plans
Conformity index	0.63 (±0.09)	0.55 (±0.1)	not significant

PTV, planning target volume.