Table 2.
Paired t test comparison between cardiac-optimized VMAT plans and IMPT plans (n = 26)
| Dosimetry variable | Cardiac-optimized VMAT plans (mean; SD) | IMPT plans (mean; SD) | P Value |
|---|---|---|---|
| Cardiac parameters (Gy) | |||
| Heart Dmax | 64.89; 3.23 | 59.24; 12.56 | .038* |
| Heart Dmean | 12.35; 7.44 | 5.91; 5.3 | <.001* |
| Heart V5 | 55.39; 28.06 | 18.1; 13.68 | <.001* |
| Heart V30 | 12.47; 11.53 | 8.37; 8.47 | .077 |
| Heart V40 | 7.87; 8.21 | 6.48; 6.94 | .401 |
| Heart V45 | 6.48; 7.02 | 5.61; 6.20 | .547 |
| Heart V60 | 2.72; 3.27 | 1.85; 2.01 | .127 |
| Aortic valve Dmax | 22.9; 16.42 | 14.06; 16.66 | .007* |
| Aortic valve Dmean | 11.42; 8.46 | 1.84; 2.58 | <.001* |
| Mitral valve Dmax | 24.56; 22.75 | 19.77; 23.97 | .053 |
| Mitral valve Dmean | 11.2; 12.25 | 4.71; 7.97 | <.001* |
| Pulmonic valve Dmax | 26.83; 18.71 | 19.3; 21.78 | .003* |
| Pulmonic valve Dmean | 14.06; 14.53 | 7.41; 14.61 | <.001* |
| Tricuspid valve Dmax | 9.74; 10.55 | 2.52; 6.9 | <.001* |
| Tricuspid valve Dmean | 5.58; 6.88 | 0.29; 0.69 | <.001* |
| Atrioventricular node Dmax | 13.39; 12.4 | 3.4; 10.4 | <.001* |
| Atrioventricular node Dmean | 8.05; 7.14 | 1.16; 4.45 | <.001* |
| Left main coronary artery Dmax | 26.34; 18.89 | 23.22; 20.22 | .148 |
| Left main coronary artery Dmean | 16.42; 14.12 | 12.18; 15.67 | .028* |
| Left anterior descending coronary artery Dmax | 27.39; 21.11 | 19.87; 23.01 | <.001* |
| Left anterior descending coronary artery Dmean | 14.37; 13.85 | 8.07; 13.94 | .001* |
| Left circumflex coronary artery Dmax | 32.58; 25.37 | 27.29; 26.24 | .008* |
| Left circumflex coronary artery Dmean | 19.33; 16.92 | 14.9; 18.64 | .011* |
| Right coronary artery Dmax | 18.13; 17.08 | 6.46; 14.42 | <.001* |
| Right coronary artery Dmean | 9.40; 9.03 | 1.92; 4.97 | <.001* |
| Left atrium Dmax | 51.82; 19.99 | 50.57; 18.98 | .325 |
| Left atrium Dmean | 17.53; 10.73 | 9.83; 8.81 | <.001* |
| Left ventricle Dmax | 35.71; 24.87 | 28.33; 27.35 | <.001* |
| Left ventricle Dmean | 8.34; 8.79 | 2.03; 3.00 | <.001* |
| Right atrium Dmax | 31.37; 23.68 | 20.08; 24.29 | <.001* |
| Right atrium Dmean | 11.11; 12.27 | 4.2; 9.05 | <.001* |
| Right ventricle Dmax | 23.65; 17.85 | 12.75; 19.38 | <.001* |
| Right ventricle Dmean | 6.93; 6.22 | 0.87; 1.94 | <.001* |
| Ascending aorta Dmax | 50.77; 17.03 | 45.31; 22.83 | .005* |
| Ascending aorta Dmean | 20.40; 10.96 | 9.16; 8.49 | <.001* |
| Pulmonary artery Dmax | 65.21; 3.27 | 62.9; 0.71 | .001* |
| Pulmonary artery Dmean | 32.24; 10.48 | 27.33; 11.64 | <.001* |
| Superior vena cava Dmax | 47.39; 20.58 | 43.98; 24.06 | .023* |
| Superior vena cava Dmean | 29.4; 18.47 | 24.42; 22.31 | .002* |
| Other OAR parameters (Gy) | |||
| Lungs: CTV V5 | 56.56; 9.24 | 26.04; 9.02 | <.001* |
| Lungs: CTV V20 | 22.38; 6.09 | 18.65; 7.04 | <.001* |
| Lungs: CTV Dmean | 13.58; 2.83 | 11.69; 10.95 | .368 |
| Spinal cord Dmax | 28.00; 7.92 | 30.25; 13.02 | .224 |
| Esophagus Dmean | 21.22; 6.97 | 17.01; 7.76 | <.001* |
Abbreviations: CTV = clinical target volume; Dmax = maximum dose; Dmean = mean dose; IMPT = intensity modulated proton therapy; OAR = organs at risk; SD = standard deviation; VMAT = volumetric modulated arc therapy.
*
Significant P value.