TABLE 3.

Dose differences to the clinical plans with the energy layer spacing (ELS) equals to 1.0, 1.2, 1.4, and spot spacing (SS) set to 1.0. Asterisks (*) indicates the difference is statistically significant (p‐value < 0.05)

		ELS1.0		ELS1.2		ELS1.4		SS1.0
ROI	Dose metrics	AVG	Std.	AVG	Std.	AVG	Std.	AVG	Std.
CTV	D98% (%)	−0.2	0.4	−0.1	0.4	−0.3	0.5	−0.2	0.5
	D98% (Gy)	−0.1	0.2	−0.1	0.2	−0.2	0.3	−0.1	0.3
	w.c.s. D95%(%)	0.0	0.2	0.1	0.2	−0.1	0.5	−0.1	0.4
	w.c.s. D95% (GyRBE)	0.0	0.1	0.0	0.1	−0.1	0.3	−0.0	0.2
Irrad. vol.	Dmean (GyRBE)	−0.1	0.1	−0.0	0.1	0.0	0.1	0.1*	0.1*
Bowel large	D0.03cc (GyRBE)	0.1	0.2	0.2	0.2	0.1	0.6	0.5	0.7
	D1cc (GyRBE)	−0.2	0.3	−0.1	0.1	−0.2	0.3	0.0	0.5
	D5cc (GyRBE)	−0.3	0.2	−0.1	0.4	−0.2	0.3	0.0	0.2
Bowel small	D0.03cc (GyRBE)	−0.4	0.4	−0.3	0.4	−0.3	0.8	−0.2	0.3
	D1cc (GyRBE)	−0.4	0.5	0.0	0.2	−0.6	0.9	0.1	0.7
	D5cc (GyRBE)	−0.5	0.7	0.1	0.3	−1.1	2.3	0.0	0.6
Duodenum	D0.03cc (GyRBE)	−0.4	1.1	−0.6	2.1	−0.0	1.5	−0.2	0.7
	D1cc (GyRBE)	0.0	0.9	0.4	0.9	0.9	1.6	0.5	1.3
	D5cc (GyRBE)	−0.7	1.9	−0.3	1.4	−0.3	2.1	0.3	0.6
Esophagus	Dmean (GyRBE)	−0.0	0.0	0.1	0.2	0.1	0.1	0.1	0.2
	D0.03cc (GyRBE)	−0.0	0.1	−0.0	0.2	−0.1	0.1	0.2	0.2
Heart	Dmean (GyRBE)	−0.1	0.2	−0.1	0.2	0.0	0.1	0.1	0.1
	D0.03cc (GyRBE)	−0.1	0.2	−0.1	0.2	−0.1	0.3	−0.0	0.3
Liver‐GTV	Dmean (GyRBE)	−0.1	0.2	−0.0	0.2	0.0	0.2	0.2*	0.1*
Lungs	Dmean (GyRBE)	0.0	0.1	0.1	0.1	0.1	0.1	0.1	0.1
	V20Gy (%)	0.0	0.1	0.1	0.2	0.1	0.2	0.2	0.4
	V5Gy (%)	0.1	0.2	0.2	0.3	0.2	0.2	0.4	0.2
Spinal cord	Dmax (GyRBE)	−0.1	0.3	−0.1	0.2	0.1	0.2	−0.1	0.3
Spinal cord PRV	Dmax (GyRBE)	−0.2	0.4	−0.3	0.4	0.2	0.5	−0.4	0.5
Stomach	D0.03cc (GyRBE)	−0.2	0.3	−0.3	0.5	0.1	0.4	0.1	0.5
	D5cc (GyRBE)	−0.0	0.2	0.1	0.2	−0.0	0.1	0.0	0.2
	V45GyRBE (cc)	0.2	0.6	0.0	0.2	0.0	0.3	0.5	1.4