Table 2.

6 MV photon beam attenuation by the ICT couch and headrest.

	Couch		Headrest
Angle	$\mathit{5}\times \mathit{5}\text{cm}$	$\mathit{10}\times \mathit{10}\text{cm}$	$\mathit{5}\times \mathit{5}\text{cm}$	$\mathit{10}\times \mathit{10}\text{cm}$
100	0.4	$-0.7$	0.3	$-0.1$
110	9.4	8	6.3	5.6
120	10	8.3	4.3	3.6
130	7.7	6.2	3.3	2.7
140	6.5	4.9	2.8	2.1
150	5.6	4.3	2.5	1.9
160	5.2	3.7	2.2	1.7
170	5	3.5	2.2	1.6
180	4.9	3.4	2.2	1.6