Table 3.
Shows rectal and bladder sparing for selective boosting and homogeneous dose escalation strategies.
| Specificity Level |
Bladder (NTCP < 10−4%) |
Rectum / Rectal Wall | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| gEUD | % VOL [cc] | gEUD | Rectum (1) |
NTCP Rectum (2) |
Rectum (3) |
% VOL [cc] Receiving | ||||||
| [Gy] | 65Gy | 75GY | [Gy] | [%] | [%] | [%] | 40 Gy | 50 Gy | 60 Gy | 70 Gy | 75 Gy | |
| One Nodule | ||||||||||||
| Scenario 1 (Δ) | −1.4 | −0.4 | 0.0 | 0.0/−1.3 | 0.0/−0.1 | 0.0/0.0 | 0.0/0.0 | +2.6/+0.2 | +4.1/+1.4 | +2.3/+1.3 | −2.8/−2.6 | −1.8/−1.9 |
| Scenario 2 (Δ) | −1.1 | −0.2 | +1.1 | +1.3/ +0.8 | +0.6/+0.2 | +0.5/+0.1 | +0.7/+0.1 | +2.4/+1.9 | +4.1/+1.3 | +3.4/+1.1 | +3.0/+0.9 | −1.0/−0.6 |
| Scenario 3 (Δ) | −0.7 | −1.4 | −0.2 | 0.0/+0.3 | −0.7/+0.1 | −0.7/+0.1 | −1.2/0.0 | −0.5/+1.1 | −1.9/+1.0 | 0.0/+1.1 | +0.6/+0.9 | +0.6/+0.7 |
| Scenario 4* (Δ) | +2.0 | +0.6 | +2.7 | +4.9/+2.7 | +3.7/+0.8 | +4.2/+0.4 | +5.3/0.0 | +4.6/+6.4 | +11.2/+3.5 | +9.0/+2.8 | +8.3/+2.4 | +8.0/+2.5 |
| Two Nodules | ||||||||||||
| Scenario 1 (Δ) | −0.5 | −0.7 | +1.0 | −1.14/−0.9 | −0.2/−0.1 | −0.1/−0.0 | 0.0/0.0 | −0.7/−0.2 | +1.6/+1.1 | +1.74/+1.40 | −0.9/0.0 | −3.0/−2.0 |
| Scenario 2 (Δ) | +1.4 | +0.9 | +5.5 | +1.1/+1.6 | +0.6/+0.3 | +0.5/+0.1 | +0.1/0.0 | +2.8/+4.3 | +2.9/+2.6 | +2.67/+1.76 | +2.8/+1.6 | +0.4/+0.9 |
| Scenario 3 (Δ) | +1.6 | +1.6 | +0.7 | −0.1/+0.6 | −0.1/+0.2 | −0.1/+0.1 | +0.1/0.0 | +2.1/+3.8 | +1.8/+2.7 | +1.38/+2.01 | +1.4/+1.3 | +1.4/+1.2 |
| Scenario 4* (Δ) | +3.2 | +4.0 | +4.7 | +4.0/+2.3 | +3.4/+0.7 | +4.0/0.4 | +0.4/0.0 | +3.6/+6.3 | +10.5/+4.9 | +9.19/+3.46 | +8.7/+2.5 | +8.3/+2.8 |
| Large Nodule | ||||||||||||
| Scenario 1 (Δ) | −1.83 | −2.10 | −3.27 | −1.8/−1.3 | −0.3/−0.1 | −0.1/0.0 | 0.0/0.0 | −7.2/−2.8 | −5.2/−2.2 | −1.31/−1.04 | +1.1/+1.1 | −1.1/−1.0 |
| Scenario 2 (Δ) | −1.04 | −0.47 | −3.48 | +0.9/+0.8 | +0.5/+0.1 | +0.4/0.0 | 0.0/0.0 | +0.8/+1.3 | +1.1/+0.4 | +1.04/+0.43 | +2.2/+1.0 | +2.9/+2.0 |
| Scenario 3 (Δ) | −1.21 | −2.08 | −0.33 | +0.9/+0.5 | +0.8/+0.2 | +0.9/+0.1 | 0.0/0.0 | −0.1/−0.1 | +1.0/+0.1 | +0.58/+0.01 | +1.0/+0.3 | +1.7/+0.4 |
| Scenario 4* (Δ) | +2.06 | +2.23 | +2.85 | +6.8/+3.7 | +4.8/+1.0 | +5.1/+0.5 | +0.5/0.0 | +11.8/+10.7 | +16.4/+4.2 | +11.01/+3.04 | +9.6/+2.5 | +9.7/+2.7 |
Abbreviations: Rectum (1), Rectum (2), Rectum (3) = represent three different NTCP model parameters described in Table 2;
*
risk-adaptive optimization using biological objective functions while selective boosting plans in scenario 1, scenario 2, and scenario 3 employ physical (dose-volume) objective functions;
Δ = the difference between homogeneous dose escalation IMRT and selective boosting IMRT (i.e. ‘+’ stands for an increase in homogeneous dose escalation IMRT). In the notation xx.x/yy.y the first number refers to rectal volume and the second to the rectal wall volume.