Table 1.

Source EPID distances, SED, and the index quality ${\text{TPR}}_{20,10}$ for the three linac used in this work.

	SED (cm)	6 MV	10 MV	15 MV
Linac A (UCSC)	159.0	0.683	0.730	0.759
Linac B (UCSC)	159.5	0.683	0.731	0.759
Linac C (USI)	158.2	0.686	0.736	0.760