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

Table 2

(a) Percentage depth doses (PDDs) obtained with EBT3 films 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 EBT3 films 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	12.8 ± 1.7	18.8 ± 1.8	27.1 ± 1.8
0	0.153	15.4 ± 1.9	20.4 ± 1.8	30.5 ± 1.6
1	1.198	35.4 ± 1.8	48.0 ± 1.7	55.3 ± 1.5
2	2.243	55.5 ± 1.8	61.3 ± 1.8	75.2 ± 1.6
5	5.378	82.4 ± 1.8	87.6 ± 0.9	85.2 ± 0.9
10	10.603	96.4 ± 1.6	99.2 ± 0.9	97.4 ± 1.2
15	15.828	100.0 ± 1.4	100.0 ± 1.1	100.0 ± 1.0

(b)

Phantom depth (mm)	WET (mm)	PDD (%)
		5 × 5 cm^2	10 × 10 cm^2	20 × 20 cm^2
N/A	0.07	7.3 ± 1.4	13.4 ± 1.8	26.8 ± 1.3
0	0.153	10.6 ± 1.6	14.1 ± 1.5	28.0 ± 1.4
1	1.198	20.0 ± 1.3	31.8 ± 1.4	38.4 ± 1.2
2	2.243	36.2 ± 1.2	40.8 ± 1.6	51.2 ± 1.6
5	5.378	59.1 ± 1.5	61.8 ± 1.4	73.4 ± 1.5
10	10.603	75.4 ± 1.4	76.4 ± 1.6	92.3 ± 1.2
15	15.828	87.4 ± 0.9	86.1 ± 1.5	104.4 ± 1.9
20	21.053	94.8 ± 1.2	91.9 ± 1.4	105.8 ± 1.9
25	26.278	97.8 ± 1.0	95.9 ± 1.1	104.3 ± 1.8
30	31.503	100.0 ± 1.0	100.0 ± 1.1	100.0 ± 1.8