Reality or pipe dream? This debate-style review walks through the long arc from 1960s 2D simulators to today’s adaptive radiotherapy suites—and then pits two experts head-to-head on whether we’re ready to ditch CT sim altogether. Dr. Sher argues yes, especially in palliative settings where sim-free workflows have already slashed time-to-treatment without compromising plan quality. He points to increasingly high-fidelity CBCT enabling real-time on-table contouring and planning. On the other side, Dr. Rosu-Bubulac argues not so fast. Even with iterative reconstruction and metal-artifact reduction, CBCT still struggles where it matters: off-center distortion, inconsistent HU values, mediocre low-contrast resolution, motion artifacts, and limited field of view. These limitations translate into real dosimetric uncertainty—particularly in anatomically complex or mobile regions. Perhaps today we can all agree sim-free planning is a great option for expediting straight-forward palliative treatments, but planning increasingly complex high-dose deliveries to moving targets should not be compromised by anything but the highest-quality planning scans. | Sher, Med Phys 2025
