Patient setup error and day-to-day esophageal motion error analyzed by cone-beam computed tomography in radiation therapy

Figures & data

Table I. Patient and tumor characteristics.

Case No.	Gender	Age (y)	Primary Site	Clinical Tumor Stage	Clinical Nodal Stage	Clinical Metastasis Stage	AJCC Stage
1	M	78	Lt	3	1	0	III
2	M	81	Mt	1	0	0	I
3	F	70	Lt	3	1	lb	IVB
4	M	64	Ut	1	0	0	I
5	M	73	Lt	3	1	lb	IVB
6	M	67	Ut	2	0	0	IIA
7	M	53	Lt	2	0	0	IIA
8	M	72	Ut	3	1	0	III
9	F	79	Ut	3	1	0	III
10	M	80	Lt	3	1	0	III
11	M	90	Lt	3	1	0	III
12	M	78	Mt	4	1	lb	IVB
13	M	73	Ut	1	1	0	IIB
14	M	74	Mt	4	1	0	III
15	F	62	Mt	1	0	0	I
16	M	68	Lt	2	0	0	IIA
17	M	55	Ut	4	1	1a	IVA
18	M	73	Mt	1	0	0	I
19	M	64	Ut	1	0	0	I
20	M	67	Lt	3	1	1b	IVB

Abberviations: AJCC=American Joint Committee on Cancer; F=female; Lt=lower thoracic; M=male; Mt=middle thoracic; Ut=upper thoracic; y=years.

Figure 1. CBCT image of the middle thoracic region, scanned under free respiration and processed after transferring data onto a Pinnacle³ workstation for planning of RT. A case with the outer esophageal wall contoured on the CBCT images (sky-blue contour).

Table II. Setup error in three dimension.

Direction	Right-left	Dorsal-ventral	Cranio-caudal
Mean (Absolute)	2 mm	4 mm	4 mm
Σ (systematic error)	2 mm	3 mm	3 mm
Max	8 mm	11 mm	13 mm
δ (random error)	0 mm	1 mm	1 mm
Stroom [30]	4 mm	6 mm	6 mm
van Herk [31]	5 mm	8 mm	8 mm

Table III. Organ motion error.

Direction	Right-left	Dorsal-ventral
mean	5 mm	5 mm
SD	3 mm	3 mm
max	15 mm	15 mm
95%*	10 mm	11 mm
σ	1 mm	2 mm
Stroom [30]	7 mm	7 mm
vanHerk [31]	8 mm	9 mm

*Margin value covering 95% of data.