Table 2.
Dose-volume indices of targets and organs at risk
| Dose index | 3DCRT | IMRT | p-value | |
|---|---|---|---|---|
| PTV54 | ||||
| Volume (mL) | 558.7 (404.3–693.1) | |||
| D2% (%)a) | 106.6 (106.2–108.3) | 105.6 (104.3–108.4) | 0.3223 | |
| D50% (%)a) | 102.9 (102.8–104.7) | 102.0 (101.2–102.6) | 0.0645 | |
| D98% (%)a) | 99.3 (99.0–99.9) | 94.1 (90.1–95.7) | 0.002 | |
| External genitalia | ||||
| Volume (mL) | 53.7 (48.1–85.2) | |||
| V20Gy (%) | 99.6 (93.5–99.8) | 59.1 (50.3–63.7) | 0.0039 | |
| V30Gy (%) | 95.3 (82.1–96.9) | 11.8 (5.7–20.7) | 0.002 | |
| V40Gy (%) | 74.8 (70.5–82.9) | 1.5 (0.1–5.9) | 0.002 | |
| Bladder | ||||
| Volume (mL) | 101 (72.6–136.8) | |||
| V35Gy (%) | 100 (100–100) | 67.3 (55.6–77.9) | 0.0039 | |
| V40Gy (%) | 100 (100–100) | 51.3 (36.5–64.7) | 0.002 | |
| V50Gy (%) | 63.3 (49.8–88.2) | 9.6 (3.1–15.7) | 0.0039 | |
| Small intestine | ||||
| V30Gy (mL) | 214.3 (123.5–329.6) | 0.0195 | ||
| V35Gy (mL) | 110.4 (77.9–253.4) | 104.8(74.5–160.5) | 0.5566 | |
| V45Gy (mL) | 83.0 (50.1–176.8) | 31.5 (26.1–48.2) | 0.0371 | |
| Large intestine | ||||
| V30Gy (mL) | 142.7 (110.8–271.7) | 0.0137 | ||
| V35Gy (mL) | 106.4(79.5–188.2) | 102.7 (65.6–132.6) | 0.1602 | |
| V45Gy (mL) | 61.3 (54.3–121.5) | 29.4 (19.7–38.2) | 0.0273 | |
| Femoral head | ||||
| Volume (mL) | 104.1 (83.7–111.3) | |||
| V30Gy (%) | 49.2 (39.8–58.9) | 52.7 (46.5–64.9) | 0.4316 | |
| V40Gy (%) | 13.9 (8.5–18.2) | 15.4 (9.9–19.5) | 0.8457 | |
| V44Gy (%) | 10.8 (5.24–14.6) | 3.7 (1.9–8.1) | 0.1055 | |
| Pelvic bone | ||||
| Volume (mL) | 851.2 (809.1–934.8) | |||
| Mean dose (Gy) | 25.6 (24.1–27.2) | 31.4 (30.1–31.8) | 0.002 | |
| V10Gy (mL) | 609.5 (555.1–662.4) | 772.2 (689.6–836.4) | 0.002 | |
| V20Gy (mL) | 559.1 (510.7–605.4) | 680.4 (603.6–716.7) | 0.002 | |
| V30Gy (mL) | 449.6 (413.6–496.3) | 560.3 (488.3–573.8) | 0.0137 | |
| V40Gy (mL) | 194.6 (168.7–223.5) | 336.2 (307.2–357.0) | 0.0039 | |
| V50Gy (mL) | 89.9 (70.2–101.8) | 27.7 (8.7–40.6) | 0.002 |
Values are presented as median (interquartile range).
3DCRT, three-dimensional conformal radiotherapy; IMRT, intensity-modulated radiotherapy; PTV54, planning target volume receiving 54 Gy; PTV45, planning target volume receiving 45 Gy; DX%, the dose covering X% of the volume of the structure; VXGy (%), the percentage of the structure volume receiving X Gy; VXGy (mL), the volume of the structure receiving X Gy.
a)
The reference dose was 54 Gy.