Table 2.
Feasibility of active heart sparing planning regarding coverage of the target and constraints in the OARs and heart parameters (t-test results)
| Active heart sparing group | |||
|---|---|---|---|
| Structure | Constraint | Parameter | Mean (SD) |
| Standard constraints | |||
| Lungs | MLD ≤ 20 Gy | MLD (Gy) | 14,546 (3.896) |
| V20 Gy ≤ 35% | V20 Gy (%) | 25,871 (7.318) | |
| V5 Gy < 65% | V5 Gy (%) | 58,500 (14.872) | |
| Esophagus | D mean 34 Gy | D mean (Gy) | 18,195 (7.486) |
| V55 Gy ≤ 33% | V55 Gy (%) | 11,803 (10.517) | |
| V60 Gy ≤ 7% | V60 Gy (%) | 6,450 (8.526) | |
| maximal dose < 105% of prescribed dose | Vol > 105% prescribed dose (cc) | 0,004 (0.020) | |
| Heart sparing constraints | |||
| Heart | MHD ≤ 10 Gy | MHD (Gy) | 6,208 (2.884) |
| V30 Gy < 20% | V30 Gy (%) | 4,305 (3.140) | |
| Left ventricle | D mean < 3 Gy | D mean Gy | 2,276 (1.756) |
| V5 Gy < 17% | V5 Gy (%) | 8,061 (17.065) | |
| V23 Gy < 5% | V23 Gy (%) | 0,267 (1.262) | |
| LAD | D max < 17 Gy | D max Gy | 6,658 (3.324) |
| V15Gy < 10% | V15 Gy (%) | 0,090 (0.469) | |
| V30 Gy < 2% | V30 Gy (%) | 0,000 (0.000) | |
| Heart base | D mean < 9 Gy | D mean (Gy) | 5,771 (2.003) |
| PTV | Volume (cc) | 293,041 (189.244) | |
| D2% (Gy) | 68,388 (1.485) | ||
| D98% (Gy) | 56,642 (16.206) | ||
PTV: planning target volume; SD, standard deviation, LAD: left anterior discending coronary artery; D mean: Mean dose; D max: maximal dose; MLD: mean lung dose; MHD: mean heart dose