ESTRO 2023 - Abstract Book

S262

Saturday 13 May

ESTRO 2023

Figure 1: examples of automated GTV delineations. Red: manual ground truth; geen: automated delineation.

Conclusion Multi-modality automated delineation of GTV of HNC was shown to be more efficient and consistent compared to manual delineation in a clinical setting and beneficial over a single-modality approach. PD-0328 Evaluation of the clinical use of a deep learning model for breast cancer treatment plan generation N. Bakx 1 , H. Bluemink 1 , E. Hagelaar 1 , D. van Gruijthuijsen 1 , J. van der Leer 1 , T. van Nunen 1 , M. van der Sangen 1 , J. Theuws 1 , C. Hurkmans 1 1 Catharina Hospital, Radiation Oncology, Eindhoven, The Netherlands Purpose or Objective The process of radiotherapy treatment planning is time-consuming due to manual and iterative steps. Besides, the outcome is dependent on the experience of the planner. The number of studies to automate this process with the help of artificial intelligence (AI) is increasing. The majority of these studies are of a retrospective nature, and only a limited number of AI models is actually implemented in the clinical routine. Recently, an AI model for dose prediction and automated treatment plan generation for left-sided whole breast radiotherapy was introduced in our clinic. In this study, the results for the first patients were monitored and evaluated. Materials and Methods A deep learning (DL) dose prediction model, based on the U-net architecture, was developed by RaySearch (RaySearch Medical Laboratories AB), trained on an in-house collected dataset and implemented in our clinical workflow in May 2022, using RayStation TPS. Treatment plans were generated using the DL model. RTTs were allowed to manually adapt plans at their own discretion. The outcomes of the first 30 patients were evaluated by monitoring the changes made and quality was assessed based on the number of predefined clinical goals fulfilled for each patient. Results Figure 1 summarizes the outcomes of all 30 patients. 67% (20 out of 30) of the plans did fulfill all clinical goals without any adjustments. 7 of these plans were still adjusted, but it did not lead to any decrease in mean heart or lung dose. Most adjustments were made to decrease high dose areas and resulted in a mean decrease of 22 cGy of the D2% (range 1 – 53cGy), which is expected to not be clinically relevant. Of the 10 plans which did not directly fulfill all clinical goals, 6 could be easily adapted to fulfill these. For 4 of these patients the D98% was lower than the demanded 3805 cGy (ranging 3785-3799 cGy), whereas for the other 2 the D2% was higher than the allowed 4285 cGy (4296 and 4297 cGy). 2 out of 30 plans still did not fulfill clinical goals after manual intervention, although the mean heart dose was significantly decreased after manual adjustments for one patient from 296 cGy to 246 cGy.