Full-resolution convergence of contour dispersion

Establish whether the contour-dispersion estimates produced by the digital-twin framework converge as the image grid spacing is refined to full resolution.

Background

The framework quantifies directional contour uncertainty from propagated contours represented on a voxel grid. A robustness experiment found that using half resolution inflated the estimated dispersion, with simulated quantization noise accounting for much of the difference.

However, the authors did not demonstrate convergence of the dispersion estimates at full resolution as grid spacing changes. The reported values are therefore characterized as bounds with a known direction rather than as demonstrably resolution-converged estimates.

References

The dispersion at full resolution has not been shown to converge with grid spacing, and the representable-variance bound of 0.247 is conservative; both should be read as bounds with a known direction.

— A digital-twin framework for forecasting treatment-day imaging with contour uncertainty in adaptive proton radiotherapy  (2609.24725 - Wu et al., 21 Sep 2026) in Section 5, Discussion, paragraph beginning “Several limitations bound the work”