Table 3.
Dose–volume analysis for planning target volume and organs at risk
| Volume | Parameter | Mean ± SD |
|---|---|---|
|
PTV |
Mean dose |
60.8 ± 2.7 Gy |
| |
Minimum dose |
43.6 ± 9.4 Gy |
| |
Maximum dose |
65.6 ± 4.2 Gy |
| |
V95% |
97.9± 2.5% |
| |
Homogeneity index (D5/D95) |
1.1 ± 0 (Range 1.0 - 1.2) |
|
Optic chiasm |
Mean dose |
30.4 ± 7.2 Gy |
| |
Maximum dose |
40.5 ± 7.6 Gy |
| |
V40 |
13.9 ± 15.9% |
| |
V45 |
0.8% ± 1.9% |
| |
V47.25 |
0% |
| |
V50 |
0% |
|
Left optic nerve |
Mean dose |
18.3 ± 8.0 Gy |
| |
Maximum dose |
29.5 ± 11.1 Gy |
| |
V40 |
3.6 ± 9.1% |
| |
V47.25 |
0.1 ± 0.3% |
| |
V50 |
0 |
|
Right optic nerve |
Mean dose |
23.4 ± 10.3 Gy |
| |
Maximum dose |
34.6 ± 11.5 Gy |
| |
V40 |
13.6 ± 21.8% |
| |
V47.25 |
0% |
| |
V50 |
0% |
|
Brainstem |
Mean dose |
22.8 ± 10.2 Gy |
| |
Maximum dose |
50.7 ± 10.3 Gy |
| |
V40 |
19.8 ± 19% |
| |
V50 |
4.5 ± 7.4% |
| |
V52.5 |
1.3 ± 3% |
| |
V55 |
0.4 ± 1% |
|
Spinal cord |
Mean dose |
1.2 ± 0.8 Gy |
| |
Maximum dose |
3.1 ± 2.4 Gy |
| |
V40 |
0% |
| |
V42 |
0% |
|
Left eye |
Mean dose |
5.2 ± 2.8 Gy |
| |
Maximum dose |
11.1 ± 4.1 Gy |
| |
V10.5 |
5 ± 17.7% |
|
Right eye |
Mean dose |
5.7 ± 3.7 Gy |
| |
Maximum dose |
13.3 ± 6.4 Gy |
| V10.5 | 5.6 ± 17% |