ESTRO 2022 - Abstract Book

S791

Abstract book

ESTRO 2022

Results The 3D gamma-index maps have been calculated for 10 patients enrolled in the clinical trial. Morphological variations that occurred in three patients have been identified.

In the figure, the gamma-index map is shown in the case of a patient affected by ACC, superimposed to the CT scan image performed at the planning stage. The clear gamma-index hot spot is correlated to the emptying of the frontal sinuses that occurred during the treatment delivery. Conclusion The results of the analysis performed on patients enrolled in the trial clearly indicate that early detection of morphological changes occurring in the tissues crossed by the beam in its entrance path towards the target volume is possible using the DP as monitoring device. In the second part of 2021 other 10 patients will be recruited to study and validate the technique on different pathologies, finalizing the systematic uncertainty studies and technique sensitivity evaluation.

PD-0898 Clinical gains through log file based automated patient specific QA in Proton Therapy

G. Guterres Marmitt 1 , A. Pin 2 , J. Free 1 , J.A. Langendijk 1 , S. Both 1

1 University Medical Center Groningen, Department of Radiation Oncology, Groningen, The Netherlands; 2 Ion Beam Applications, IBA research, Louvain-la-Neuve, Belgium Purpose or Objective In radiation therapy, it is crucial to ensure that the treatment dose delivered matches the physician approved planned dose. Uncertainties in the treatment planning system (TPS) dose calculations, machine delivery errors or data corruption might lead to differences between intended and delivered doses. As such, patient specific quality assurance (PSQA) of dose distributions, through experimental validation of individual fields, is standardly used. These measurement-based plan QAs (m-QA), however, are labor intensive and impose a bottleneck to treatment efficiency. In this work, we investigate the clinical benefits over 2 years implementation of an automated QA platform at the Groningen Proton Therapy Center.