Table 3.
Achieved Average Dosimetric Indices, Beam-on Times and the Associated P-Values for the X1 10 mm Jaw (X1-10), X1 20 mm Jaw (X1-20), and Eclipse VMAT Plans for Lung, Anus, and Brain Sites. A P-Value .05 was Considered Significant (Bold Text).
| Site | Dosimetric constraint/parameter | X1-10 | X1-20 | Eclipse | P (X1-10 vs Eclipse) | P (X1-20 vs Eclipse) | P (X1-10 vs X1-20) |
|---|---|---|---|---|---|---|---|
| Lung | PTV_high D95% 100% | 100.2 | 100.5 | 100.0 | .10 | .06 | .09 |
| PTV_high D2%<106% | 104.9 | 106.3 | 105.0 | .39 | .01 | .01 | |
| Esophagus Dmean<34Gy | 12.5 | 13.4 | 15.2 | .003 | .08 | .19 | |
| Heart V40<35% | 1.7 | 2.2 | 2.0 | .10 | .14 | .04 | |
| Lungs Dmean<15Gy | 13.1 | 14.5 | 10.9 | .12 | .07 | .02 | |
| Lungs V20<30% | 23.2 | 25.4 | 17.5 | .09 | .06 | .03 | |
| Lung_contra Dmean<15Gy | 5.0 | 6.1 | 5.3 | .31 | .09 | .05 | |
| Lung_ipsi Dmean<15Gy | 19.0 | 19.9 | 17.4 | .09 | .004 | .15 | |
| SpinalCord Dmax<45Gy | 26.7 | 25.9 | 25.6 | .36 | .46 | .13 | |
| Vessel_Aorta Dmax<70Gy | 64.3 | 65.1 | 64.4 | .47 | .05 | .02 | |
| Vessel_SVC Dmax<70Gy | 65.7 | 66.5 | 65.7 | .49 | .01 | .03 | |
| Beam-on Time, min | 9.0 | 5.5 | 1.0 | <.001 | <.001 | <.001 | |
| Anus | PTV_high D95% 100% | 100.3 | 101.0 | 100.1 | .06 | .06 | .06 |
| PTV_intermed D95% 100% | 102.9 | 101.2 | 100.0 | .26 | .08 | .33 | |
| PTV_low D95% 100% | 100.2 | 100.9 | 100.0 | .22 | .13 | .13 | |
| PTV_high D2%<106% | 105.3 | 106.3 | 105.0 | .40 | .16 | .22 | |
| Bladder Dmean<24Gy | 34.2 | 33.5 | 31.4 | .06 | .02 | .10 | |
| Bladder V45<50% | 29.9 | 31.7 | 28.8 | .24 | .01 | .29 | |
| Bowel Dmax<54Gy | 49.5 | 48.7 | 47.2 | .04 | .11 | .01 | |
| Bowel V25<300cc | 280.8 | 275.7 | 333.1 | .04 | .22 | .15 | |
| Bowel V30<250cc | 212.2 | 210.8 | 256.8 | .04 | .17 | .16 | |
| Femur_L V30<50% | 11.3 | 13.9 | 11.6 | .48 | .21 | .23 | |
| Femur_R V30<50% | 10.9 | 12.1 | 13.2 | .35 | .40 | .36 | |
| Beam-on Time, min | 17.0 | 10.1 | 3.0 | <.001 | <.001 | <.001 | |
| Brain | PTV_60 D95% 60Gy | 60.0 | 60.1 | 60.1 | .41 | .29 | .19 |
| PTV_60 D2%<106% | 105.1 | 106.2 | 104.2 | .24 | .05 | .01 | |
| CI<1.2 | 0.99 | 1.02 | 1.01 | .14 | .24 | .12 | |
| BrainStem Dmax<45Gy | 33.7 | 35.8 | 36.7 | .13 | .42 | .26 | |
| Chiasm Dmax<45Gy | 21.2 | 22.3 | 28.1 | .03 | .05 | .08 | |
| Cochlea_contra Dmax<30Gy | 2.3 | 2.6 | 5.9 | .03 | .06 | .14 | |
| Cochlea_ipsi Dmax<30Gy | 7.7 | 9.1 | 12.6 | .05 | .07 | .07 | |
| Optic_nrv_contra Dmax<45Gy | 11.2 | 11.5 | 19.9 | .01 | .02 | .11 | |
| Optic_nrv_ipsi Dmax<45Gy | 17.2 | 18.0 | 23.6 | .03 | .04 | .12 | |
| Skin D1cc<45Gy | 43.1 | 44.2 | 35.3 | .02 | .01 | .14 | |
| Beam-on Time, min | 6.8 | 4.8 | 1.7 | <.001 | <.001 | <.001 |