Table 1.

Depth error (PMMA) for different cases.

Depth/cm	5	7.5	10	12.5	15	17.5	20
2 Gy
ΔR50/mm	0.59 ± 0.75	0.31 ± 0.90	−0.09 ± 1.06	−0.55 ± 0.65	0.13 ± 1.44	−0.29 ± 0.85	−0.58 ± 1.44
4 Gy
ΔR50/mm	0.15 ± 0.97	−0.08 ± 0.63	−0.18 ± 0.71	−0.31 ± 0.59	0.05 ± 1.36	−0.46 ± 0.86	−0.26 ± 1.32