Table 5.
Comparison of volumes and dosimetry based on a synthetic CT created from CT1 with CT2 at fraction 16.
| Planning CT1 |
#16 synthetic CT1 |
CT2 at fraction 16 |
#16 synthetic CT2 |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | ||
| Volume (cc) | Ipsilateral Parotid Gland |
28.8 | (11.5) | 26.1 | (11.2) | 26.1 | (11.3) | 26.3 | (11.3) |
| Contralateral Parotid Gland |
28.6 | (10.6) | 26.1 | (9.9) | 25.9 | (10.0) | 26.2 | (10.0) | |
| Mean dose (cGy) | PTV_HR | 218.2 | (1.3) | 218.1 | (1.8) | 218.4 | (2.2) | 218.1 | (2.3) |
| Ipsilateral | 137.2 | (25.2) | 136.8 | (27.8) | 137.2 | (27.6) | 136.7 | (27.0) | |
| contralateral | 86.9 | (31.2) | 89.7 | (31.1) | 87.0 | (29.9) | 86.8 | (29.2) | |
| Maximum dose (cGy) | PRV_Brainstem | 146.2 | (12.9) | 146.9 | (21.3) | 143.0 | (17.0) | 145.5 | (23.7) |
| PRV_Spinal Cord | 139.5 | (6.5) | 142.5 | (15.0) | 138.3 | (9.3) | 140.9 | (15.5) | |
| D95% | PTV_HR | 96.6 | (1.8) | 95.1 | (2.6) | 94.9 | (4.5) | 93.6 | (6.9) |
| n | (%) | n | (%) | n | (%) | n | (%) | ||
| D95%<95% | PTV_HR | 1 | (5) | 6 | (30) | 6 | (30) | 7 | (35) |