Analyses of the factors influencing the accuracy of three-dimensional ultrasound in comparison with cone-beam CT in image-guided radiotherapy for prostate cancer with or without pelvic lymph node irradiation

Table 3 Analyses of factors that influence the accuracy of 3DUS to CBCT

	N	%	SI	P	%	LR	P	%	AP	P
	N	%	OR (95% CI)	P	%	OR (95% CI)	P	%	OR (95% CI)	P
Age (years)
≤ 70	21	28.7	1		10.5	1		17.5	1
> 70	28	35.6	1.37 (1.07, 1.76)	0.012	14.6	1.46 (1.02, 2.08)	0.036	26.5	1.70 (1.28, 2.26)	< 0.001
Irradiated with pelvic lymph nodes
No	27	29.9	1		10.8	1		20.9	1
Yes	22	35.7	1.30 (1.02, 1.67)	0.036	15.1	1.47 (1.04, 2.07)	0.03	24.1	1.20 (0.91, 1.59)	0.189
3DUS modality
TAUS	30	32.2	1		16.6	1		21.5	1
TPUS	19	32.7	1.02 (0.80, 1.31)	0.85	7.9	0.43 (0.30, 0.63)	< 0.001	23.3	1.11 (0.84, 1.46)	0.476
Bladder volume (mL)				0.093			0.004			0.031
< 300	10	35.3	1		7.6	1		15.8	1
300~399	11	29.3	0.76 (0.53, 1.10)	0.147	18.1	2.70 (1.56, 4.68)	< 0.001	24.5	1.73 (1.12, 2.66)	0.013
400~499	12	28.2	0.72 (0.51, 1.03)	0.07	11.7	1.62 (0.92, 2.87)	0.098	25.1	1.78 (1.17, 2.70)	0.007
≥ 500	16	35.9	1.03 (0.74, 1.43)	0.862	13.8	1.96 (1.14, 3.36)	0.015	23.6	1.64 (1.09, 2.46)	0.017
Rectum volume (mL)				0.498			0.42			0.079
< 40	18	34.2	1		14.2	1		20.5	1
40~59.9	15	32.5	0.93 (0.69, 1.25)	0.618	12.6	0.87 (0.58, 1.31)	0.504	26.2	1.38 (0.99, 1.92)	0.055
≥ 60	16	30.3	0.84 (0.62, 1.13)	0.238	11.1	0.75 (0.49, 1.15)	0.189	20.3	0.99 (0.70, 1.40)	0.941

CBCT Cone-beam computed tomography, 3DUS Three-dimensional ultrasound, TAUS Transabdominal ultrasound, TPUS Transperineal ultrasound, SI Superior-inferior, LR Left-right, AP Anterior-posterior, OR Odd ratio, CI Confidence interval

ISSN: 1748-717X