PMC

A: Mean relative overlap of pairs of neighborhoods that are champions of the same parameter against the mean correlation coefficient of their Euler characteristic time series (feature correlation). B: Pairwise feature correlations of the champions of two exemplary parameters. C: Mean feature correlation of champions against their performance in feature-based classification. D1: Feature-based classification for volumetric samples can be performed using the active sub-networks of each sample in each time step, then pooling over samples. D2: Alternatively, the 25 largest neighborhoods can be found within a single volumetric sample, which are then analyzed as other neighborhood samples. E1: Mean feature correlation for volumetric samples of various radii when the technique in D1 is employed. E2: Same, when the method outlined in D2 is employed. Only data from one volumetric sample are shown. F: Feature-based classification accuracies for volumetric samples using the purely volumetric (blue) or sub-neighborhood-based (red) techniques, or a random control for sub-neighborhoods (yellow). For sub-neighborhood-based and random conditions, we pooled data from all 25 volumetric samples. Black stars indicate Bonferroni-corrected significance (volumetric vs. sub-neighborhoods: Wilcoxon rank-sum test; sub-neighborhoods vs. random: Wilcoxon signed-rank test; n.s.: not significant, *: p < 0.01, **: p < 0.001, ***: p < 0.0001). G: Feature correlation against classification accuracy for volumetric samples using the purely volumetric (blue; Pearson’s r = −0.954, p = 0.012) or sub-neighborhood-based (red; Pearson’s r = −0.811, p = 0.096) technique.

(a,b) Nominal dose distributions in large spot and small spot plans with and without volumetric repainting technique in an example patient; (c,d) Interplay dose distributions without volumetric repainting in large spot and small spot plans in the same patient; (e,f) Interplay dose distributions with volumetric repainting in large spot and small spot plans in the same patient. Note: Red contour = CTV, Blue = 6930 cGy(RBE), yellow = 6650 cGy(RBE); green = 3000 cGy(RBE); LSNR = large spot plan with no volumetric repainting, SSNR = small spot plan with no volumetric repainting, LSVR = large spot plan with five volumetric repaintings, SSVR = small spot plan with five volumetric repaintings

Dose volume histogram (DVH) comparison of some planning treatment volume (PTV), rectum, and bladder between the hybrid technique and the two field volumetric modulated arc therapy (VMAT) technique.