Surface and Buildup Region Dose Measurements with Markus Parallel-Plate Ionization Chamber, GafChromic EBT3 Film, and MOSFET Detector for High-Energy Photon Beams

Table 3

(a) Percentage depth doses (PDDs) obtained with a MOSFET dosimeter in a water equivalent RW3 phantom using 6 MV photon beams for different field sizes at SSD = 100 cm. (b) Percentage depth doses (PDDs) obtained with a MOSFET dosimeter in a water equivalent RW3 phantom using 15 MV photon beams for different field sizes at SSD = 100 cm.

(a)

Phantom depth (mm)	WET (mm)	PDD (%)
		5 × 5 cm^2	10 × 10 cm^2	20 × 20 cm^2
N/A	0.07	17.4 ± 1.3	25.5 ± 1.3	34.5 ± 1.8
0	1.800	40.1 ± 1.4	46.4 ± 1.6	57.2 ± 1.6
1	2.845	56.8 ± 1.0	60.6 ± 1.5	69.3 ± 1.5
2	3.890	66.5 ± 1.2	70.2 ± 1.6	77.2 ± 1.6
5	7.045	87.8 ± 1.1	89.0 ± 1.4	97.5 ± 1.7
10	12.250	106.3 ± 0.8	105.2 ± 1.2	105.5 ± 1.9
15	17.475	100.0 ± 0.9	100.0 ± 1.1	100.0 ± 1.8

(b)

Phantom depth (mm)	WET (mm)	PDD (%)
		5 × 5 cm^2	10 × 10 cm^2	20 × 20 cm^2
N/A	0.07	9.0 ± 1.6	16.4 ± 1.9	28.9 ± 1.8
0	1.800	24.6 ± 1.7	33.0 ± 1.9	40.0 ± 1.7
1	2.845	30.0 ± 1.6	40.0 ± 1.8	52.4 ± 1.6
2	3.890	42.3 ± 1.5	50.3 ± 1.6	59.1 ± 1.6
5	7.045	62.1 ± 1.6	70.0 ± 1.7	74.8 ± 1.4
10	12.250	79.4 ± 1.7	88.7 ± 1.6	90.8 ± 1.5
15	17.475	89.9 ± 1.3	97.9 ± 1.5	95.2 ± 1.6
20	22.700	96.7 ± 1.2	99.0 ± 1.6	99.2 ± 1.8
25	27.925	98.3 ± 1.3	99.3 ± 1.7	99.8 ± 1.8
30	33.150	100.0 ± 1.0	100.0 ± 1.2	100.0 ± 1.1