Table 1.
Dose volume data for IMPT plans with different beam angle arrangements in average by three prostate cancer patients.
| ROI | Statistic * | Two Angles (Conventional) | Two Angles (Optimized) | Three Angles (Optimized) | Four Angles (Optimized) | Three Angles ** (Class) | |
|---|---|---|---|---|---|---|---|
| Rectum | V30Gy (%) | 22.6 | 16.8 | 15.7 | 16.0 | 15.9 | (29.6%) |
| V40Gy (%) | 18.2 | 13.9 | 12.6 | 13.2 | 12.8 | (29.7%) | |
| V50Gy (%) | 14.4 | 11.3 | 10.2 | 10.7 | 10.7 | (25.7%) | |
| V60Gy (%) | 10.8 | 8.9 | 8.0 | 8.4 | 8.3 | (23.1%) | |
| V70Gy (%) | 6.9 | 6.2 | 5.7 | 5.7 | 5.8 | (15.9%) | |
| Dmean (Gy) | 17.2 | 14.3 | 12.8 | 13.7 | 13.5 | (21.5%) | |
| Bladder | V30Gy (%) | 22.7 | 22.5 | 22.6 | 23.7 | 22.9 | (−0.4%) |
| V40Gy (%) | 19.3 | 18.7 | 18.7 | 19.4 | 19.2 | (0.5%) | |
| V50Gy (%) | 16.2 | 15.5 | 15.5 | 15.9 | 15.9 | (1.9%) | |
| V60Gy (%) | 13.1 | 12.3 | 12.4 | 12.8 | 12.6 | (3.8%) | |
| V70Gy (%) | 9.4 | 8.8 | 8.8 | 9.2 | 8.9 | (5.3%) | |
| Dmean (Gy) | 17.2 | 17.1 | 17.1 | 17.5 | 17.2 | (0.0%) | |
* All dose volume indices are based on dose in Gy (relative biological equivalence [RBE]); ** The reductions of dose volume data for class three-angle plans comparing to conventional two-angle plans are provided in parentheses.