Table 2.

Description of Proton versus IMRT dosimetric re-planning comparisons on paediatric CNS patients. [Key: ASC—Astrocytoma, CRA—Craniopharyngioma, EPE—Ependymoma, LGG—Low Grade Gliomas, MED—Medulloblastoma, OGL—Optic Glioma].

Study	“n” of Patients	Age Range (Yr.)	Years	Radiotherapy Technique Protons IMRT		Diagnosis	Target Dose Px	Main Findings
Bishop et al. [11]	52	8.9 median	1996–2012	various	various	CRA	50.4 Gy (RBE)/50.4 Gy	PBT and IMRT produced equivalent outcomes related to survival and solid and cystic disease control.
Boehling et al. [12]	10	5–14	2007–2009	3 fields	5–7 fields	CRA	50.4 Gy (RBE)/50.4 Gy	Proton therapy resulted in significant sparing of normal tissues.
Brower et al. [13]	3	Not specified	2012	3 fields	9–11 fields	LGG	50 Gy	Proton therapy is an effective modality for reducing the dose deposition to non-target tissues.
Moteabbed et al. [14]	6	4–15	2013	3–4 fields	5–7 fields	MED EPE CRA ASC	50.4–54 Gy	Choosing proton therapy for paediatric patients with brain tumors is highly beneficial when considering second malignancies.
Paganetti et al. [15]	8	4–14	2012	3–4 fields	6–7 fields	OGL	52.2 Gy (RBE)/52.2 Gy	Proton therapy shows an overall advantage when estimating the risk for developing a second malignancy within the irradiated area.
Merchant et al. [16]	40	Paediatric	2008	various	various	MED EPE CRA OGL	54 Gy	A reduction in the mean dose from protons would have long-term clinical advantages for children with MED, CRA and OG.
Athar et al. [6]	6	0.75–14	2010	6 fields	6 fields	Cranial region	54 Gy	Protons can offer the advantage of a lower integral dose compared with IMRT.
Brodin et al. [17]	10	4–15	2007–2009	3 fields	2 Arc fields	MED	23.4 and 36 Gy	IMPT plans, including secondary neutron dose contribution, compared favourably to the photon techniques in terms of all radiobiological risk estimates.