The dosimetric significance of using 10 MV photons for volumetric modulated arc therapy for post-prostatectomy irradiation of the prostate bed

Figures & Tables

Category	6 MV Mean ± SDOM	10 MV Mean ± SDOM	Percent Increase	p-value	Power
Bladder-CTV D₅₀	32.5 ± 4.3 Gy	29.7 ± 3.9 Gy	−8.62%	0.013	0.79
Bladder-CTV D₇₀	18.5 ± 3.7 Gy	16.2 ± 3.2 Gy	−12.4%	0.011	0.81
Rectum D₃₅	49.5 ± 3.3 Gy	46.8 ± 3.9 Gy	−5.45%	6.6 × 10^-3	0.88
Rectum D₅₅	28.5 ± 2.7 Gy	26.7 ± 2.7 Gy	−6.32%	0.023	0.68
Right Femoral Head D₁₀	34.12 ± 0.86 Gy	29.80 ± 0.99 Gy	−12.66%	1.2 × 10-4	1.0
Left Femoral Head D₁₀	32.74 ± 0.94 Gy	29.4 ± 1.1 Gy	−10.20%	8.3 × 10-5	1.0
CTV Min Dose	65.53 ± 0.38 Gy	65.29 ± 0.21 Gy	−0.3662%	0.41	0.12
CTV Max Dose	71.01 ± 0.37 Gy	70.53 ± 0.31 Gy	−0.6760%	0.10	0.37
CTV Mean Dose	68.30 ± 0.29 Gy	67.68 ± 0.27 Gy	−0.9078%	0.019	0.72
CTV Percent Volume Covered by the 95% Isodose Line	100%	100%	0%	N/A	N/A
PTV Min Dose	64.42 ± 0.29 Gy	64.42 ± 0.29 Gy	0%	0.10	0.37
PTV Max Dose	71.78 ± 0.29 Gy	71.76 ± 0.33 Gy	−0.02786%	0.94	0.051
PTV Mean Dose	68.39 ± 0.38 Gy	67.94 ± 0.28 Gy	−0.6580%	0.063	0.47
PTV Percent Volume Covered by the 95% Isodose Line	100%	100%	0%	N/A	N/A
Body V₅	(27.0 ± 1.0)%	(26.5 ± 1.0)%	−1.85%	2.2 × 10-3	0.96
Global Max Dose	71.80 ± 0.38 Gy	71.76 ± 0.33 Gy	−0.05571%	0.89	0.052
Arc 1 Monitor Units	325 ± 17 MU	311.8 ± 9.8 MU	−4.06%	0.41	0.12
Arc 2 Monitor Units	330 ± 15 MU	312 ± 10 MU	−5.5%	0.19	0.24
Conformity Index	1.127 ± 0.013	1.091 ± 0.015	−3.194%	6.8 × 10-4	0.99
Integral Dose	207 ± 12 Gy-L	191 ± 11 Gy-L	−7.73%	1.1 × 10-5	1.0