Table 2 The residual errors (mm) of the chest wall and the breast surface (in parenthesis) after different alignments of the orthogonal kV setup images

Laser setup

3.5 (4.3)

4.5 (5.1)

3.6 (3.8)

4.5 (4.5)

11.3 (13.4)

14.4 (15.9)

MID_V

2.9 (3.4)

4.2 (5.5)

2.3 (2.6)

3.5 (4.1)

8.9 (10.3)

13.0 (16.6)

MID_R+UPPER_ST

1.5 (2.6)

1.9 (3.2)

2.2 (2.4)

2.6 (3.0)

5.3 (8.2)

6.6 (10.1)

MID_V+UPPER_ST

1.8 (2.9)

2.3 (3.9)

2.1 (2.4)

2.7 (3.3)

6.0 (8.9)

7.6 (12.1)

MID_V+MID_R

2.9 (3.4)

3.1 (4.4)

2.2 (2.5)

2.8 (3.3)

8.8 (10.3)

9.7 (13.3)

MID_V+UPPER_ST+MID_R

2.2 (3.1)

2.2 (3.7)

2.4 (2.3)

2.6 (3.0)

7.2 (9.4)

7.3 (11.4)

UPPER_ST

-

2.3 (3.5)

-

2.9 (3.3)

-

7.8 (11.1)

MID_R

-

2.8 (3.8)

-

3.0 (3.3)

-

9.1 (11.8)

Online match to optimal position¹

1.3 (2.6)

1.8 (3.1)

2.1 (2.4)

2.2 (3.1)

4.8 (8.2)

6.0 (9.9)