ESTRO 2024 - Abstract Book

S4953

Physics - Quality assurance and auditing

ESTRO 2024

Figure 1. Relative differences in maximum dose the spinal cord as a result of treatment delivery errors. The plotted values are calculated as differences in the dose to 0.03 cm3 of the volume to the OAR receiving the highest dose in the plan with the error vs the same quantity in the original plan. Cold and hot cocktails are combinations of errors in MLC position, collimator angle and output, all within machine tolerance.

Conclusion:

The use of fallback planning to create dosimetrically equivalent and similarly robust treatment plans for common treatment machines is feasible. Plan robustness differences to introduced delivery errors need to be further assessed.

Keywords: Delivery errors, dose mimicking, Fallback Planning

References:

1. Hernandez V, Hansen CR, Widesott L, Bäck A, Canters R, Fusella M, et al. What is plan quality in radiotherapy? The importance of evaluating dose metrics, complexity, and robustness of treatment plans. Radiotherapy and Oncology. 2020;153:26-33. https://doi.org/10.1016/j.radonc.2020.09.038. 2. Lehmann J, Hussein M, Barry MA, Siva S, Moore A, Chu M, et al. SEAFARER–A new concept for validating radiotherapy patient specific QA for clinical trials and clinical practice. Radiotherapy and Oncology. 2022;171:121 8. https://doi.org/10.1016/j.radonc.2022.04.019.