Table 4.

Disagreement (% error in central axis dose at $d_{max}=1.7\text{cm}$) between the measured and EPID‐calculated water phantom dose for 6 MV

Field size $({\text{cm}}^2)$	Error (.%)
$2\times 2$	2.6%
$5\times 5$	0.9%
$10\times 10$	0.3%
$20\times 20$	1.0%
$25\times 25$	1.1%