Table 3.

Calibration condition sets that produced PSD dose measurements that were ≤0.5% different than those measured using the ionization chamber under identical (IMRT QA) conditions. The calibration factors used to calculate PSD doses under treatment conditions using the pelvic phantom were produced using the calibration conditions highlighted by the gray box.

Calibration factor set number	Field sizes (cm2)	Doses used per field size (cGy)	Percent difference from IC dose
2	5	10	0.3%
	10	10
24	20	10	0.1%
	30	10
29	5	10	0.3%
	5	50
	10	10
71	10	10	0.5%
	20	10
	30	50
148	10	10	0.5%
	20	10
	30	10
	30	50