Table 1.

Details of phase II and III randomised controlled trials that involved PBT (n = 8).

Authors, year	Condition	Aim	RCT phase	Age range (years)	Sample size
Bush et al, 2016 [31]	Hepatocellular carcinoma	To report interim analyses of PBT versus transarterial chemo-embolization	Phase 2	Not stated	69
Desjardins et al, 2006 [32]	Uveal melanoma	To determine the effect of systematic transpupillary thermotherapy after PBT	Phase 3	22–88	151
Gragoudas et al, 2000 [33]	Choroidal melanoma	To determine the effect of a reduction in PBT dose from standard 70 CGE to 50 CGE on treatment outcomes	Phase 3	19–86	188
Habl et al, 2016 [34]	Prostate cancer	To explore the safety and feasibility of primary hypofractionated irradiation with PBT and carbon ions in a raster scan technique	Phase 2	40–80	92
Kim et al, 2013 [35]	Prostate cancer	To investigate the feasibility of hypofractionated PBT in treatment of prostate cancer	Phase 2	44–85	82
Liao et al, 2018 [36]	Non–small cell lung cancer	To compare outcomes of passive scattering PBT versus IMRT	Phase 3	33–85	149
Shipley et al, 1995 [37]	Prostate cancer	To evaluate the possible increased efficacy of a higher dose of radiation on the local recurrence rate and patient survival	Phase 3	46–85	202
Zietman et al, 2010 [38]	Prostate cancer	To test the hypothesis that increasing radiation dose improves clinical outcomes	Phase 2	45–91	393

Abbreviations: RCT = Randomised controlled trial; PBT = Proton beam therapy; IMRT = Intensive modulated radiotherapy; CGE = Cobalt gray equivalent.