TABLE 5.
Average dose parameters for the target and organ at risk using various segment numbers for low‐ and high‐risk patients.
| The average dose parameters for target and OAR | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low‐risk parietns | High‐risk parietns | ||||||||||||
| Dosimetric parameters | p‐value | Dosimetric parameters | p‐value | ||||||||||
| 60 segments | 100 segments | 150 segments | 60 segments vs. 100 segments | 100 segments vs. 150 segments | 60 segments | 100 segments | 150 segments | 60 segments vs. 100 segments | 100 segments vs. 150 segments | ||||
| PTV‐Rectum | PTV‐Rectum‐Urethra | ||||||||||||
| D98% (Gy) | 35.83 | 35.91 | 35.92 | <0.01 | <0.01 | D98% (Gy) | 35.33 | 35.41 | 35.45 | <0.01 | <0.01 | ||
| Dmax (Gy) | 38.69 | 38.25 | 38.12 | <0.01 | <0.01 | Dmax (Gy) | 42.67 | 42.20 | 42.08 | <0.01 | <0.01 | ||
| PTV/rectum | PTV/rectum | ||||||||||||
| D98% (Gy) | 33.65 | 33.61 | 34.74 | 0.65 | 0.01 | D98% (Gy) | 35.17 | 34.90 | 34.84 | 0.96 | 0.65 | ||
| Rectum | Rectum | ||||||||||||
| V36Gy (cc) | 0.01 | 0.01 | 0.02 | 0.05 | 0.99 | V36Gy (%) | 0.07 | 0.06 | 0.06 | <0.01 | 0.62 | ||
| V32.6 Gy (%) | 0.85 | 0.80 | 1.01 | 0.05 | 0.96 | V32.6 Gy (%) | 0.62 | 0.53 | 0.53 | <0.01 | 0.55 | ||
| V29Gy (%) | 2.40 | 2.31 | 2.56 | 0.06 | 0.97 | V29Gy (%) | 1.80 | 1.68 | 1.65 | 0.05 | 0.05 | ||
| V25.3 Gy (%) | 4.41 | 4.30 | 4.53 | 0.02 | 0.95 | V25.3 Gy (%) | 4.34 | 4.13 | 4.10 | 0.04 | 0.08 | ||
| V21.7 Gy (%) | 7.01 | 6.90 | 7.12 | 0.04 | 0.93 | V21.7 Gy (%) | 9.65 | 9.20 | 9.15 | 0.04 | 0.34 | ||
| V18.1 Gy (%) | 11.40 | 11.36 | 11.69 | 0.32 | 0.99 | V18.1 Gy (%) | 21.13 | 20.63 | 20.89 | 0.17 | 0.86 | ||
| Bladder | Bladder | ||||||||||||
| V37Gy (cc) | 1.98 | 1.10 | 0.74 | <0.01 | <0.01 | V37Gy (%) | 5.20 | 4.78 | 4.65 | <0.01 | 0.01 | ||
| V18.1 Gy (%) | 37.87 | 36.85 | 36.29 | <0.01 | 0.01 | V18.1 Gy (%) | 37.54 | 36.67 | 36.61 | <0.01 | 0.32 | ||
| UrethraPRV | UrethraPRV | ||||||||||||
| V38Gy (cc) | 0.00 | 0.00 | 0.00 | 0.03 | 1.00 | Dmax (Gy) | 39.71 | 39.47 | 39.35 | <0.01 | <0.01 | ||
| Left Femural Head | |||||||||||||
| Dmax (Gy) | 16.60 | 16.07 | 16.19 | <0.01 | 0.40 | Dmax (Gy) | 15.21 | 14.74 | 14.74 | 0.01 | 0.56 | ||
| V14.5 Gy (%) | 3.03 | 1.50 | 1.26 | <0.01 | 0.14 | V14.5 Gy (%) | 0.38 | 0.12 | 0.15 | 0.06 | 0.72 | ||
| Right Femural Head | |||||||||||||
| Dmax (Gy) | 16.80 | 15.98 | 15.75 | <0.01 | 0.03 | Dmax (Gy) | 14.48 | 14.34 | 14.14 | 0.27 | 0.04 | ||
| V14.5 Gy (%) | 4.11 | 2.59 | 2.00 | <0.01 | 0.01 | V14.5 Gy (%) | 0.14 | 0.12 | 0.03 | 0.29 | 0.01 | ||
| CTV‐UrethraPRV | |||||||||||||
| D95% | 39.36 | 39.31 | 39.28 | 0.88 | 0.89 | ||||||||
Note: Parameters with significant differences are indicated in red text.
Abbreviations: CTV, clinical target volume; Dmax, maximal dose; D95%, dose administered to 95% of volume; D98%, dose administered to 98% of volume; OAR, organ at risk; PRV, planning organ at risk volume; PTV, planning target volume; PTV−Rectum−Urethra, PTV minus rectum and urethra structure; PTV/rectum, common areas of PTV and rectum.