Table 2.

Target volume and OAR dosimetry for treatment plans using 7 mm vs 5 mm PTV margins.

				Mean		Mean of Difference
OAR		Priority	n	7 mm	5 mm		p-value
Bladder
	V40.8 (%)	3	10	13.57	11.1	−2.47	0.0005	***
	V48.6 (%)	2	10	9.84	7.85	−1.99	0.0007	***
	V60 (%)	2	10	0.89	1.46	0.57	0.3434
	D0.03 (Gy)	1	10	61.11	61.34	0.237	0.3267
Rectum
	V24.6 (%)	R	10	33.68	28.98	−4.7	<0.0001	****
	V32.4 (%)	R	10	24.97	20.48	−4.49	<0.0001	****
	V40.8 (%)	3	10	19.12	14.64	−4.48	<0.0001	****
	V43.5 (%)	3	10	17.59	13.32	−4.27	<0.0001	****
	V52.8 (%)	3	10	12.09	8.56	−3.53	0.0002	***
	V57 (%)	2	10	8.1	5.2	−2.9	0.001	***
	V60 (%)	1	10	0.43	0.39	−0.04	0.7509
	D0.03 (Gy)	2	10	60.38	60.26	−0.116	0.4549
Penile Bulb
	Dmean (Gy)	4	10	18.03	19.81	1.779	0.5692
Right Femoral Head
	D0.03 (Gy)	R	10	30.17	28.39	−1.775	0.0576
Left Femoral Head
	D0.03 (Gy)	R	10	30.73	29.67	−1.052	0.0727
Bowel Bag
	V43.5 (%)	3	10	1.284	0.968	−0.316	0.3127
	V46.2 (%)	3	10	1.05	0.722	−0.328	0.3372
				Mean		Mean of Difference
Target Volume		Priority	n	7 mm	5 mm		p-value
CTV
	V99 (%)	1	10	99.98	99.92	−0.06	0.1679
PTV
	V95 (%)	1	10	99.39	99.54	0.15	0.2126
	V99.9 (%)	4	10	85.58	89.58	4	0.0298	*
	D0.03 (%)	2	10	106.7	105.9	−0.74	0.0046	**