ESTRO 2024 - Abstract Book

S3535

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

Fig. 1 PQI values for automatic and manual plans for the three prescriptions.

In all three prescriptions, manual plans show better and statistically significant outcomes for the brain, brainstem, and spinal cord. This is due to the operator who expressively focused more on sparing these organs during the manual planning process. On the other hand, automatic plans yield superior results for the cochlea, eyes, lachrymal glands, larynx, lens, lips, oral cavity, constrictor muscles, and thyroid. While the mean values for the brain, brainstem, and spinal cord in the automatic plans are well within the clinical constraints (mandatory and optimal), the mean values in the first and second prescriptions of manual plans for the thyroid and constrictor muscles exceed the mandatory value and for the larynx it falls outside the optimal range. The deliverability parameters, which reflect the complexity of a plan, are significantly higher for automatic plans. All the automatic QA plans meet the acceptability requirement (>90%), with eighteen of them satisfying the optimal criterion (>95%), achieving an average passing rate of (98.0±2.7)%. The delivered time for the automatic plans is approximately one minute longer than the manual plans.

Conclusion:

Auto-planning proves to be a valuable tool that significantly reduces planning times, enhances OARs sparing keeping a good PTVs coverage, and ensures acceptable QA results, despite the increased complexity of the plans. Moreover, the marginal increment for the delivery times (around 1 min for each patient) will not have a significant impact on clinical routine.

Keywords: auto-planning, H&N, MCO

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