Table 8.

Dosimetric comparison of organs at risk (OARs) for the 3 treatment plans

	3DCRT (n = 9)	VMAT (n = 11)	Tomotherapy (n = 10)	P value
Colon dose (%)
V35	34.7 [23.9–66.1]	13.0 [7.0–29.3]*	10.6 [3.5–17.1]*	0.002
V25	50.3 [41.2–74.3]	30.0 [18.5–53.0]&	30.4 [10.8–37.4]*	0.020
V15	64.9 [51.2–81.0]	68.0 [52.0–73.2]	57.1 [33.8–80.6]	0.796
Peritoneum dose (%)
V50.4	35.8 [18.0–50.0]	3.6 [1.0–5.0]*	2.7 [0.5–5.2]*	0.001
V40	51.7 [28.0–73.0]	12.0 [7.0–21.0]*	*	0.002
V30	58.7 [35.2–79.7]	27.0 [20.0–37.0]*	23.6 [17.5–34.6]*	0.013
V25	66.7 [32.5–83.0]	45.0 [33.7–52.0]	36.6 [30.4–45.5]	0.147
Rectum dose (%)
V50.4	24.4 [15.6,–52.6]	2.2 [0.0–13.4]*	5.3 [0.3–7.4]*	0.003
V40	97.5 [94.2–100.0]	37.0 [26.0–68.4]*	34.1 [26.2–40.6]*	< 0.001
V30	97.5 [96.3–100.0]	86.5 [69.3–90.0]	56.4 [49.3–66.0]*§	< 0.001
Bladder dose (%)
V50.4	40.7 [31.2–46.7]	2.0 [1.0–14.0]*	5.7 [0.7–13.3]*	0.001
V40	100.0 [99.8–100.0]	28.0 [23.3–34.1]*	28.6 [21.3–46.1]*	< 0.001
V30	100.0 [100.0–100.0]	59.5 [52.0–71.0]*	50.5 [43.2–73.6]*	< 0.001
Bone marrow dose (%)
V50	27.8 [24.1–29.2]	4.0 [2.7–5.0]*	5.5 [3.0–8.1]*	< 0.001
V40	44.0 [39.7–45.5]	16.0 [13.0–17.0]*	19.6 [16.9–23.0]*	< 0.001
V30	58.9 [54.8–62.9]	37.0 [34.2–38.5]*	39.2 [38.0–45.8]*	< 0.001
V20	88.8 [81.5–91.3]	70.0 [63.0–75.4]*	70.4 [67.1–73.3]*	0.002
V10	91.9 [84.4–95.6]	89.8 [87.0–94.0]	90.2 [87.1–92.7]	0.936

3DCRT three-dimensional conformal radiation therapy, VMAT volumetric modulated arc therapy, V_50.4, V₄₀, V₃₅, V₃₀, V₂₅, V₁₅ = volume receiving ≥ 50.4, ≥ 40, ≥ 35, ≥ 30, ≥ 25, ≥ 15 Gy, respectively

Differences were compared using the Kruskal–Wallis tests for continuous variables

Data are presented as the median [interquartile range]

*P < 0.05 versus 3DCRT in the Bonferroni post hoc test

^§P < 0.05 versus VMAT in the Bonferroni post hoc test

^&P = 0.09 versus 3DCRT in the Bonferroni post hoc