ESTRO 2022 - Abstract Book

S1501

Abstract book

ESTRO 2022

great effort to increase the number of patients that benefit from this procedure. Therefore, we aimed to quantify this increase and to look for improvement areas. Materials and Methods The Varian RPM and RGSC respiratory gating systems are non-invasive devices. Our protocol considers that a patient is valid for DIBH when she achieves threshold values above 1 cm and can hold the breath around 20 seconds. Plans were extracted from the ARIA database using the scripting API provided by Varian. A total of 573 left-sided breast plans were retrieved, ranging from 2018 to 2021. All plans were manually reviewed and assigned to either DIBH-category or no-DIBH category. Additionally, we reviewed the CT simulation notes of the patients that did not perform DIBH in 2021. All these patients were subsequently categorized into seven categories (Figure 1). The not specified category was used for those simulations that had no reason noted down. The not candidate category was used for patients not suitable for DIBH (health issues related), while those patients who did not receive proper guidelines before the simulation and did not achieve DIBH were included in the not informed category. Finally, the others category contains causes that did not fit in the previous categories.

Results A total of 353 (61.6%) patients were able to comply with the DIBH requirements. Figure 2 shows that since 2018, DIBH patients have increased from 38.8% to 72.2%. A total of 45 (27.8%) patients did not undergo DIBH treatment during 2021. The not specified category shows that we have a non-negligible amount of CT simulation notes without explanation. The not candidate category is related to patients’ characteristics, so there is no room for improvement. The not informed category has been identified as the improvement area easier to work on as it can be reduced by promoting awareness of the benefits of DIBH among radiation oncologists.

Conclusion Even though DIBH has been implemented correctly in our centre, we have reached a plateau. Published literature reports DIBH compliance rates up to 90%, showing that we still have room for improvement. The first three categories are all related to training issues, and hence the implementation of new training programs would reduce them. Furthermore, it has been highlighted to therapists the importance of noting down the reasons ( not specified category) for further analysis and improvement. The following actions will be taken: