Table 2.
Organ-at-risk rectum volume variations for 8 number of observations: Planning computed tomography volume (cc) versus weekly cone-beam computed tomography volume (cc)
| Number of sample | CTp volume (cc) of OAR rectum | Weekly CBCT volume (cc) range of OAR | Subvolume (%) range of OAR rectum | |
|---|---|---|---|---|
|
| ||||
| CBCT minimum- CBCT maximum | CBCT mean | |||
| 1 | 65.63 | 55.34-70.08 | 63.62 | 8.77-20.79 |
| 2 | 82.55 | 70.21-110.05 | 87.23 | 8.58-18.76 |
| 3 | 90.67 | 81.22-107.61 | 96.97 | 7.02-18.72 |
| 4 | 70.04 | 55.03-113.09 | 89.31 | 5.40-25.53 |
| 5 | 75.11 | 65.10-117.85 | 93.35 | 7.83-28.44 |
| 6 | 95.07 | 78.50-121.91 | 100.55 | 7.54-23.31 |
| 7 | 105.45 | 82.81-164.86 | 132.98 | 6.12-25.35 |
| 8 | 159.37 | 95.50-168.30 | 123.56 | 10.60-28.27 |
OAR: Organ at risk, CBCT: Cone-beam computed tomography, CTp: Planning CT