Table 1.
Constraints | ||||
Volume | Type | Limit | ||
PTV | Max dose | 105% of DPx | ||
PTV | Mean dose | 101% of DPx | ||
Rectum & anus | Max dose | 102% of DPx | ||
PTV shell 50mm | Max dose | 50% of DPx | ||
Unspecified tissues | Max dose | 105% of DPx | ||
Objectives | ||||
Priority | Volume | Type | Goal | Parameters |
1 | PTV | ↓LTCP | 0.8 | DPx = 78Gy, α = 0.8 |
2 | Rectum | ↓EUD | 20Gy | k = 12 |
3 | OAR 2 | ↓EUD | 10Gy | k = 8 |
4 | PTV shell 5mm Skin ring 20mm |
↓Max dose ↓Max dose |
80% of DPx 20% of DPx |
|
5 | Rectum | ↓Mean dose | 5Gy | |
6 | Anus | ↓Mean dose | 5Gy | |
7 | Bladder | ↓Max dose | 5Gy | |
8 | PTV shell 15mm PTV shell 25mm |
↓Max dose | 50% of DPx 30% of DPx |
|
9 | Left & right femoral heads | ↓Max dose | 50% of DPx |
α, cell sensitivity;EUD, equivalent uniform dose;k, volume effect; LTCP, logarithmic tumour control probability; PTV, planning target volume;DPx, prescribed dose.
The priorities assigned to the objectives are used in the a priori MCO, guaranteeing for each patient generation of a pareto-optimal plan with clinically favorable balances between all treatment objectives. (Courtesy: A.W. Sharfo).