Table 3 The suggested asymmetrical expansion margins of ITV for target delineation of each liver segment are derived from the amplitudes of DIR from helical CT to 4DCTs
Segment | Average amplitude ± SD (mm) | ITV margin (mm) (to cover more than 95% of each tumor) | |||||||
|---|---|---|---|---|---|---|---|---|---|
Helical CT to phase 0 CT | Helical CT to phase 50 CT | ||||||||
LR | AP | SI | LR | AP | SI | LR | AP | SI | |
S1 | 0.8 ± 3.1 | 0.4 ± 1.6 | − 2.5 ± 3.9 | − 1.1 ± 2.2 | 1.4 ± 1.8 | 3.0 ± 3.5 | − 2.2 and 2.3 | − 0.4 and 2.3 | −4.4 and 4.7 |
S2 | −1.1 ± 2.5 | −0.6 ± 3.7 | −2.4 ± 4.9 | −0.8 ± 2.6 | 0.6 ± 2.1 | 3.9 ± 4.1 | − 2.3 and 0.5 | −2.4 and 1.6 | − 4.7 and 5.9 |
S3 | −0.3 ± 2.9 | −1.8 ± 3.1 | −2.9 ± 3.5 | − 0.7 ± 3.1 | 0.6 ± 3.0 | 2.9 ± 2.5 | − 2.2 and 1.1 | −3.3 and 2.1 | − 4.6 and 4.1 |
S4a | 0.4 ± 2.8 | −1.4 ± 2.1 | −0.6 ± 3.9 | −1.0 ± 1.7 | 0.1 ± 2.4 | 2.4 ± 3.4 | −1.8 and 1.8 | −2.4 and 1.3 | − 2.4 and 4.0 |
S4b | −0.5 ± 1.5 | − 1.7 ± 2.2 | −2.4 ± 3.5 | − 1.8 ± 1.6 | 0.3 ± 2.2 | 2.9 ± 3.3 | − 2.6 and 0.3 | −2.8 and 1.4 | − 4.1 and 4.5 |
S5 | −2.2 ± 1.7 | −1.4 ± 2.1 | −1.9 ± 2.2 | − 2.3 ± 1.3 | 1.7 ± 2.4 | 3.7 ± 2.1 | −3.0 and 0.0 | −2.4 and 2.9 | − 3.0 and 4.7 |
S6 | 0.2 ± 4.3 | − 1.2 ± 2.3 | −3.2 ± 2.9 | 0.1 ± 4.1 | 1.0 ± 2.3 | 3.3 ± 3.7 | − 1.9 and 2.3 | −2.3 and 2.1 | −4.6 and 5.1 |
S7 | 0.3 ± 4.2 | − 1.7 ± 2.8 | −3.6 ± 4.4 | −1.1 ± 2.6 | 1.8 ± 2.1 | 5.0 ± 4.8 | − 2.4 and 2.3 | −3.1 and 2.8 | −5.7 and 7.3 |
S8 | −2.2 ± 2.5 | − 1.5 ± 2.6 | −1.9 ± 3.4 | −1.3 ± 1.5 | 1.8 ± 2.5 | 3.2 ± 3.1 | −3.4 and 0.0 | −2.8 and 3.0 | − 3.5 and 4.7 |
mean | −0.5 ± 3.1 | − 1.2 ± 2.6 | −2.4 ± 3.7 | −1.1 ± 2.5 | 1.0 ± 2.4 | 3.4 ± 3.5 | − 2.5 and 1.2 | −2.5 and 2.2 | − 4.2 and 5.0 |