Dosimetric Studies of Mixed Energy Intensity Modulated Radiation Therapy for Prostate Cancer Treatments

Table 2

Dose volume comparison for three plans (6 MV, 15 MV, and mixed energy) in two algorithms.

Volume	Cone collapsed convolution				Pencil beam
	6 MV	15 MV	Mixed energy	Avg. 𝑃	6 MV	15 MV	Mixed energy	Avg. 𝑃
	(Mean ± standard dose)				(Mean ± standard dose)
PTV
MaxDose (Gy)	90.93±2.4	88.41±3.1	90.05±1.2	0.036	92.34±1.7	90.31±1.3	91.45±1.9	0.034
MinDose (Gy)	70.06±2.8	67.20±2.5	69.28±0.8	0.029	71.09±0.8	68.09±2.5	70.36±1.4	0.051
AvgDose (Gy)	79.22±3.6	79.12±3.7	80.45±2.1	0.015	80.12±0.5	80.21±2.2	81.23±1.1	0.013
Rectum
V66 Gy (%)	18.55±2.8	14.58±2.1	16.77±4.7	0.034	19.05±2.8	15.09±1.7	17.26±4.6	0.048
V40 Gy (%)	42.36±3.1	40.04±1.7	39.53±2.8	0.062	43.23±3.3	38.58±2.8	40.16±2.9	0.058
V20 Gy (%)	60.32±4.6	57.83±2.9	58.55±3.6	0.041	60.65±1.4	58.04±4.0	58.87±3.1	0.031
D50% (Gy)	33.19±2.3	27.21±0.09	31.20±2.9	0.052	33.73±2.6	27.94±3.5	31.54±2.5	0.05
Bladder
V66 Gy (%)	16.54±2.1	17.42±2.1	16.94±1.9	0.022	16.77±3.6	17.90±2.9	17.58±2.1	0.026
V40 Gy (%)	42.01±3.6	41.77±1.8	42.74±4.2	0.028	43.23±3.1	43.06±4.0	43.39±3.2	0.003
V20 Gy (%)	76.29±3.2	75.66±2.6	75.00±3.8	0.008	76.29±1.2	75.97±1.9	75.01±2.8	0.009
D50% (Gy)	35.54±2.9	34.87±0.9	35.02±2.4	0.010	37.58±4.6	35.50±3.4	35.06±2.9	0.034
Femoral heads
V20 Gy (%)	84.84±5.4	84.03±3.9	83.12±4.2	0.041	84.26±3.6	84.68±2.9	83.55±4.3	0.029
D50% (Gy)	25.04±3.4	25.06±2.5	24.28±1.9	0.029	25.84±2.7	25.06±1.4	24.69±3.1	0.032
Monitor units
AvgMU	755±10.6	655±11.58	776±8.4	0.035	742±12.3	654±10.46	777±13.5	0.028

Avg.: average; MaxDose: maximum dose; MinDose: minimum dose; AvgDose: average dose; and MU: monitor units.