Table 1.

Patient, tumor and treatment characteristics

	Proton CSI (n=19)	Photon CSI (n=21)
	Median (range)	Median (range)
Age at RT (years)	29.9 (16.9–49.9)	32.7 (16.6–60.4)
Follow-up (months)	26.3 (11–63)†	57.1 (4–103)†
Height (cm)	175 (154–191)	179 (147–194)
Gender	n (%)	n (%)
Male	14 (74%)	12 (57%)
Female	5 (26%)	9 (43%)
Chang Stage
M0	18 (95%)*	15 (71%)*
M1	0	1 (5%)
M2	1 (5%)	0
M3	0	4 (19%)
M4	0	1 (5%)
Gross residual tumor at RT
< 1.5 cm2	14 (74%)	17 (81%)
≥ 1.5 cm2	5 (26%)	4 (19%)
Risk Group
Average	14 (74%)	14 (67%)
High	5 (26%)	7 (33%)
Histology
Classical	13 (68%)	16 (76%)
Desmoplastic	6 (32%)	4 (19%)
Anaplastic	0	1 (5%)
Chemotherapy
Any	16 (84%)	17 (81%)
Before RT	4 (21%)	7 (33%)
During RT	5 (26%)	5 (24%)
After RT	15 (79%)	13 (62%)
Prescribed CSI dose
23.4–26 Gy	6 (32%)	4 (19%)
30 Gy	4 (21%)	8 (38%)
36–40 Gy	9 (47%)	9 (43%)

Prescription dose (Gy-RBE; Gy)	Median (range)	Mean (SD)	Median (range)	Mean (SD)
CSI	30.6 (23.4–36)	30.9 (5.6)	30.6 (23.4–40)	31.9 (4.7)
Boost	23.4 (18–30.6)	23.7 (5.2)	21.6 (14–30.6)	21.5 (4.3)
Total	54 (54–57.8)	54.6 (1.1)	54 (25.5–56)	52.9 (6.3)
Mean normal structure dose (%)
Thyroid (% CSI dose)	0.009% (0.006–0.69%)‡	0.05% (0.16)‡	79% (54–86%)‡	78% (7.2)‡
Right Cochlea (% total dose)	60% (44–91%)	65% (12.9)	67% (50–97%)	67% (10.8)
Left Cochlea (% total dose)	69% (44–84%)	65% (10.7)	71% (54–100%)	74% (13.4)
Pituitary (% total dose)	63% (44–75%)	61% (9.2)	67% (50–75%)	66% (6.7)
Vertebrae (% CSI dose)	69% (58–120%)‡	73% (13.6)‡	100% (87–111%)‡	100% (5.4)‡

Abbreviations: CSI= Craniospinal irradiation; RT=Radiation therapy; SD=standard deviation

^*p= 0.05 comparing M0 with M1-4

^†p= 0.004

^‡p<0.0001