Table 1.
PTV and OARs dose objectives used for VMAT treatment planning optimisation
| Volume | DVH objectives | Empty bladder protocol (n = 49) Median (Range) |
Full bladder protocol (n = 41) Median (Range) |
p value |
|---|---|---|---|---|
| PTV | Dose received by 98% of the volume D98% ≥ 57 Gy |
57.9 Gy (57.3–58.5) | 57.8 Gy (57.4–58.4) | 0.35 |
| Dose received by 50% of the volume D50% = 60 Gy |
60 Gy | 60 Gy | N/A | |
| Dose received by 2% of the volume D2% ≤ 63 Gy |
61.5 Gy (61.2–62.2) | 61.6 Gy (61.0–62.0) | 1.00 | |
| Rectum | Volume receiving 42 Gy V42Gy ≤ 60% |
28.3% (17.3–61.0) | 29.0% (10.5–58.9) | 0.75 |
| Volume receiving 50 Gy V50Gy ≤ 50% |
16.8% (9.4–44.5) | 17.1% (2.9–38.6) | 0.72 | |
| Volume receiving 54 Gy V54Gy ≤ 30% |
12.3% (6.6–35.2) | 12.0% (1.4–30.9) | 0.51 | |
| Volume receiving 58 Gy V58Gy ≤ 15% |
6.9% (2.8–21.4) | 6.9% (0.4–18.4) | 0.49 | |
| Bladder | Volume receiving 42 Gy V42Gy ≤ 50% |
51.2% (23.7–84.9) | 24.7% (5.6–72.5) | <0.05 |
| Volume receiving 50 Gy V50Gy ≤ 25% |
39.6% (17.2–66.7) | 18.5% (4.5–61.5) | <0.05 | |
| Volume receiving 62 Gy V62Gy ≤ 5% |
0.1% (0–2.5) | 0% (0–2.0) | 0.09 |