RESULTS
RefleXion X1 plans were successfully created for all 5 pediatric medulloblastoma patients. Figures 1 illustrates a comparison between axial, sagittal, and coronal dose distributions between an Eclipse VMAT plan and a RefleXion X1 plan.
Table 1 displays the summary of the average dosimetric indices and parameters achieved for VMAT and X1 plans. The dose to 2% of PTV (PTV D2%) was reported as 39.2 Gy for VMAT plans and 41.3 Gy for X1 plans. This difference was not found to be statistically significant (p=0.08). The OAR doses were comparable between the RefleXion X1 and Eclipse VMAT plans. Statistical significance was detected only for the difference in Dmean to the bowel bag, with RefleXion X1 plans reporting a lower average Dmean compared to Eclipse VMAT of 1.4 Gy (p=0.04).
The average beam-on time for Eclipse VMAT and RefleXion X1 plans were 3.6 min and 16.7 min, respectively (p<0.01). The average total treatment time from imaging to the end of treatment completion was also calculated for Eclipse VMAT as 29.2 min (range 16.3 – 43.5 min). No average total treatment time was acquired for RefleXion X1 because no treatment was delivered using this technology.