Table 3. Comparison of ITV3DCT with ITVCBCT and ITVMIP for the phantom.
| Amplitude (mm) | ITVI (CC) | ITVII (CC) | ITVIII (CC) | ITVCBCT (CC) | ITVMIP (CC) | Mean ITVI/ITVCBCT | Mean ITVII/ITVCBCT | Mean ITVIII/ITVCBCT | Mean ITVI/ITVMIP | Mean ITVII/ITVMIP | Mean ITVIII/ITVMIP |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 39.6–53.1 (46.0±4.6) | 19.8–36.9 (28.9±5.7) | 28.8–34.2 (32.7±1.4) | 31.5–32.9 (32.2±0.39) | 31.9–33.3 (32.4±0.43) | 1.43 | 0.92 | 1.06 | 1.42 | 0.89 | 1.01 |
| 10 | 36–62.1 (48.5±9.5) | 18–44.1 (34.4±7.9) | 32.4–42.3 (38.9±3.0) | 35.6–40.5 (39.9±0.44) | 41.4–43.2 (42.3±0.46) | 1.22 | 0.89 | 1.05 | 1.15 | 0.81 | 0.92 |
| 15 | 34.2–71.1 (46.0±14.9) | 32.4–53.1 (41.8±5.6) | 39.6–48.6 (45.4±2.3) | 45.9–48.2 (46.8±0.62) | 48.9–50.4 (49.5±0.38) | 0.99 | 0.92 | 1.05 | 0.93 | 0.84 | 0.92 |
| Overall | 34.2–71.1 (46.8±10.4) | 18–53.1 (35±8.3) | 28.8–48.6 (39.0±5.7) | 31.5–48.2 (39.6±6) | 31.9–50.4 (41.4±7) | 1.21 | 0.91 | 1.06 | 1.16 | 0.85 | 0.95 |
| Z | −3.79 | −2.03 | −2.06 | −2.4 | −3.57 | −1.749 | |||||
| P | <0.000 | 0.041 | 0.044 | 0.016 | 0.000 | 0.082 |
ITV3DCT refers to the internal gross tumor volume of three-dimensional computed tomography (CT). ITVMIP refers to the internal gross tumor volume of four-dimensional CT; ITVI refers to the internal gross tumor volume of 3DCT scan mode I, ITVII refers to the internal gross tumor volume of 3DCT scan mode II, ITVIII refers to the internal gross tumor volume of 3DCT scan mode III.