ESTRO 2024 - Abstract Book

S124 ESTRO 2024 • Reduce risk of potential injury during patient transfer, by reducing the number of procedures required Invited Speaker

• Improve patient/carer experience of palliative radiotherapy compared to current pathway

This presentation will cover the need for rapid response palliative care programs, the benefits of making these RTT lead services; touch on the knowledge, skills and competence required by RTTs to lead such a service; introduce the benefits of using the MR Linac (and other competing technologies) to deliver this service; share the steps we have taken and are yet to take to implement such a service in our department (including RTT-led research associated with the project).

3540

Tools and recommendations for commissioning and quality assurance of deformable image registration in radiotherapy

Lando Bosma

UMC Utrecht, Radiotherapy, Utrecht, Netherlands

Abstract:

Multiple tools are available for commissioning and quality assurance of deformable image registration (DIR), each having their own advantages and disadvantages in the context of radiotherapy. The selection of appropriate tools should depend on the available input, desired output, time requirement, and DIR application. In reality, it also depends on the availability of these metrics in commercial software. Discussions were hosted by the ESTRO Physics Workshop 2021 on Commissioning and Quality Assurance for DIR in Radiotherapy. A consensus was reached on what requirements are needed for commissioning and quality assurance, and what combination of tools is associated with this. For commissioning, we recommend the target registration error of manually annotated anatomical landmarks or the distance-to-agreement of manually delineated contours to evaluate alignment. These should be supplemented by the distance to discordance and/or biomechanical criteria to evaluate plausibility. Digital phantoms can be useful to evaluate DIR for dose accumulation but are currently only available for a limited range of anatomies, image modalities and types of deformations. For quality assurance of DIR for contour propagation, we recommend at least visual inspection of the registered image and contour. For quality assurance of DIR for warping quantitative information such as dose, Hounsfield units or PET data, we recommend visual inspection of the registered image together with image similarity to evaluate alignment, combined with an inspection of the Jacobian determinant or bending energy and the dose (gradient) to evaluate plausibility. We acknowledge that some of these metrics are still missing in currently available commercial solutions.

3541

Toxicity of brachytherapy

Piotr Wojcieszek