Table 2.

Percentage gamma index passing rate between two-dimensional (2D) and three-dimensional (3D) volumetric modulated arc therapy quality assurance for patients with nasopharyngeal cancer (NPC) and oesophageal cancer (ESO)

Acceptance criteria (%/mm)	NPC	ESO	p-value
4%/4 mm
2D	98.57 ± 2.83	99.58 ± 0.49	0.13
3D	98.84 ± 0.57	99.21 ± 0.45	0.03
3%/3 mm
2D	96.67 ± 1.36	97.57 ± 1.63	0.07
3D	96.86 ± 1.60	97.95 ± 0.78	0.01
2%/2 mm
2D	85.81 ± 3.80	87.65 ± 4.43	0.17
3D	92.74 ± 4.10	95.38 ± 1.82	0.01