Table 4.

Heart and lung dose volume histogram (DVH) endpoints mean and range of the absolute difference between the reference and perturbed VMAT and TFiF plans for the directions (left, posterior, and inferior) that contribute to an increase in the OAR dose.

				10 mm		5 mm		3 mm
				VMAT	TFiF	VMAT	TFiF	VMAT	TFiF
Heart		ΔV5 (%)		4.1 (2.9–5.5)	3.9 (3.0–4.7)	1.5 (2.0–4.1)	1.4 (1.1–2.0)	0.1 (0.0–0.2)	0.0 (0.0–0.1)
		ΔV10 (%)		1.9 (1.7–34.4)	1.9 (1.5–3.3)	1.3 (1.0–2.0)	1.3 (1.0–1.8)	0.1 (0.0–0.3)	0.1 (0.0–0.3)
		ΔV25 (%)		1.8 (1.6–2.5)	1.5 (1.3–2.3)	0.9 (0.7–1.4)	0.7 (0.4–1.5)	0.0 (0.0–0.2)	0.1 (0.1–0.2)
		ΔDm (%)		0.5 (0.7–1.3)	0.5 (0.8–1.4)	0.4 (0.4–0.6)	0.2 (0.1–0.4)	0.1 (0.0–0.3)	0.0 (0.0–0.1)
Left lung		ΔV5 (%)		3.0 (2.4–5.6)	2.7 (2.3–4.6)	1.6 (1.2–2.5)	1.3 (1.0–2.6)	0.2 (0.2–0.6)	0.2 (0.1–0.3)
		ΔV20 (%)		1.9 (1.7–4.0)	1.8 (1.4–3.5)	1.2 (1.0–2.3)	1.0 (0.7–1.9)	0.2 (0.1–0.4)	0.1 (0.2–0.3)
		ΔDm (%)		0.8 (0.6–1.4)	0.8 (0.5–1.4)	0.5 (0.4–1.0)	0.5 (0.3–0.9)	0.4 (0.3–0.5)	0.4 (0.3–0.4)
Right breast		ΔV5 (%)		0.1 (0.0–0.1)	0.1 (0.0–0.1)	0.0 (0.0–0.0)	0.0 (0.0–0.1)	0.0 (0.0–0.0)	0.0 (0.0–0.1)
		ΔDm (Gy)		0.1 (0.0–0.2)	0.1 (0.0–0.1)	0.0 (0.0–0.1)	0.0 (0.0–0.1)	0.0 (0.0–0.1)	0.0 (0.0–0.1)

VMAT, volumetric modulated arc therapy; TFiF, tangential field in field; D_x, dose in Gy received by x% of the volume; D_m, mean dose; V_x, volume receiving x Gy.

In gray data with mean difference ≤ 2%, in bold >3%.