Table 3.

Clinical goals for target structures and OARs alongside average results from all 67 CBCT dose calculations for the non-robust and robust plans. 93% of prescription (37.25 Gy) was used for the CBCT target coverage constraints. The number of calculation pairs (robust vs non-robust CBCT calculations) that differ by 2% is reported along with the proportion of robust and non-robust calculations achieving the clinical goal.

ROI	Statistic	Clinical goal	Robust		Non-robust		p-values	% of pairs above 2% difference	% of plans CBCT dose calculations meeting clinical goal
			median	IQ range	median	IQ range			Robust	Non-robust
Breast CTV	D98 (Gy)	>37.25	38.5	38.0–38.6	37.9	37.3–38.4	<0.01	24	97	76
	D95 (Gy)	>37.25	38.8	38.4–39.1	38.6	38.0–38.9	<0.01	17	100	91
	D50 (Gy)	40 ± 0.8	40.2	39.8–40.3	40.1	39.8–40.2	<0.01	0	100	100
	D2 (Gy)	<42.85	41.7	41.5–41.9	41.4	41.2–41.6	<0.01	0	100	100
Axillary CTV	D95 (Gy)	>37.25	39.7	39.0–39.9	39.8	39.2–40.0	<0.01	0	100	100
	D50 (Gy)	40 ± 0.8	40.4	40.0–40.7	40.6	40.3–40.9	<0.01	0	74	65
	D2 (Gy)	<42.85	41.4	41.1–41.8	41.9	41.2–42.1	<0.01	3	98	100
IMC CTV	D95 (Gy)	>37.25	38.3	37.8–39.2	39.4	38.1–39.7	<0.01	26	80	82
	D50 (Gy)	40 ±  0.8	40.1	39.6–40.6	40.7	40.0–41.0	<0.01	17	76	45
	D2 (Gy)	<42.85	41.5	41.1–42.2	41.9	41.2–42.3	0.30	15	85	92
Superficial Breast CTV	D95 (Gy)	>37.25	38.5	37.9–38.8	37.3	36.2–38.0	<0.01	70	94	55
Heart	mean (Gy)	<6	3.9	3.4–6.0	4.0	3.5–5.8	0.23	30	74	82
Left Lung	V17Gy (%)	<35	30.5	29.5–32.2	30.8	29.8–32.0	0.72	48	97	97
	mean (Gy)	<15	13.1	12.8–13.8	13.2	12.8–13.5	0.32	55	100	100
Right Breast	mean (Gy)	<3.5	3.3	3.2–3.3	3.3	3.2–3.4	<0.01	21	91	86

CBCT = Cone beam CT. IQ = inter-quartile. CTV = Clinical Target Volume.

p < 0.05 shown in bold.