S2784
RTT - RTT contouring, target definition, and treatment planning
ESTRO 2026
adapted plan (adaptive plan generated by Raystation)The following extra optimisation was applied to the RS-adapted plan to further improve its plan quality: 4. FineTune (An optimization tool in RS, applied only to clinical goals unmet) 5. Single warm- start (W) + FineTune (applied only to clinical goals unmet) 6. Triple warm-start (WWW) + FineTune (applied to clinical goals unmet)For efficiency, timings were recorded for different steps in the workflow: i) total runtime (defined as fully automated online adaptive workflow from CBCT acquisition to plan approval), ii) manual structure evaluation and adaptation of the DLS generated contours, iii) plan optimization for plans 4, 5 and 6. Results: With respect to efficacy, the scheduled plans, due to small margins and large anatomical changes, rarely met clinical goals. For PTV V95%, only in 1 patient this clinical goal was already met with the RS-adapted plan, whereas other adapted plans succeeded for all patients (figure 1a). For Dmax PTV (D0.03cm ³≤ 5885cGy), RS-adapted and RS- adapted+Finetune were insufficient for all patients (fig 1b). For Dmax bowel (D0.03cm ³≤ 5885cGy) RS-adapted failed in 3 cases but all other adapted plans succeeded (fig 1c).With respect to efficiency the average times (s) were i) runtime 239 (162-297), ii) structure evaluation and adaptation 114 (48-250), iii) plan 4; optimization 308 (202-447), plan 5; 168 (69-287) and plan 6; 164 (124-203) (fig 2). Plan approval itself was consistently around 40 s.
Conclusion: The module ‘automated replanning’ in Raystation v2025 delivers both in efficacy and efficiency. Additional iterations improved plan quality, though at the expense of longer optimization times. Keywords: online adaptive radiotherapy, cbct
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