ESTRO 2023 - Abstract Book

S575

Monday 15 May 2023

ESTRO 2023

images or the creation of synthetic CT images based on the CBCT images. In patients requiring plan adaption, rescanning, re-delineation and re-planning must be performed. All parts of this workflow will be prone to uncertainties, which must be investigated before large-scale offline adaptation can be implemented in daily clinical routines. Strict criteria for plan adaption will aid the decision workflow. With all of these tasks in place, an offline adaptive radiotherapy strategy may be possible for every curatively intended patient. A clinical benefit in terms of significantly increased overall survival and reduced toxicity has been shown for lung cancer patients after the implementation of adaptive radiotherapy. In lung cancer patients, the most commonly observed anatomical changes are atelectasis, pleural effusion, pneumonia, tumour shrinkage, and differential shifts between tumour and lymph nodes. Up to 25% of the patients may benefit from treatment adaptation due to these anatomical changes. Most of the anatomical changes are systematic and thus, a single plan adaptation during the treatment course will be sufficient. In head and neck cancer patients, tumour shrinkage may lead to overdosage of organs at risk which may be counteracted by plan adaption. Additionally, shrinkage and irreproducible patient fixation may lead to target dose depletion. Retrospective data does appear to suggest a benefit of adaptive radiotherapy in terms of higher loco-regional control. In the pelvic and abdominal regions, the anatomical changes are more likely random variations depending on e.g. bladder and rectum filling. A plan selection strategy has been used in both bladder and cervical cancers, leading to reduced toxicity. Different treatment plans are created based on different fillings and at the daily treatment, the most appropriate plan is selected. However, these patients may benefit more from online adaptive radiotherapy. SP-0688 Architectural design for optimised radiotherapy departments C. Kolodziej 1 1 Technische Universität Dresden, Chair for Social and Health Care Buildings and Design, Dresden, Germany Abstract Text Future planning of radiotherapy departments can improve by considering the statement ‘form follows function’. With this the architecture is supposed to be planned for the workflow and not the workflow is adjusted for the architecture. With this, the aim is to develop floor plan configurations to help improve the workflow for staff and the therapy process for patients. The implementation of evidence-based design in healthcare facilities can positively influence workflow, travel paths, well being, and quality of stay. (Mahmood, 2021) Transferred to radiotherapy, an optimized architecture and built environment of radiotherapy departments is a prerequisite for treatment. Given the complexity of RT departments, their specific features, and the current lack of planning requirements, a multilayered study is approached. With my Ph.D. Project on “Healthcare Design for Radiotherapy – Planning Criteria to Improve Workflow and the Physical Environment with Architecture and Design”, an analysis of built radiotherapy departments is conducted to improve future architectural planning from the perspective of workflow and built environment for all user groups. In Study Phase A, a list of rooms was drafted, and clusters were categorized to structure the complexity of radiotherapy departments. Six cluster formations were conducted: Reception, Outpatient, Imaging, Planning, Therapy, and Personnel/ Service with each dedicated rooms. The cluster formations were further analyzed by their relation, distance, and arrangement towards each other. The analysis was inspecting differences and similarities in patterns of spatial relationship for clusters and rooms. In addition, the comparability of different-d departments, measured by the number of therapy rooms, was investigated. With this comparative floor plan analysis, a classification of radiotherapy departments based on organizational and spatial characteristics was developed. This Study Phase A focuses on the environment of radiotherapy departments by establishing typologies and spatial criteria of cluster formations and room organization by analyzing floor plans of radiotherapy departments in German hospitals. Study Phase B analysis the workflow and travel paths of all users of RT departments. Looking at similarities and differences of travel paths of Radiation Physicians, Radio physicists, Radiation Nurses, Administration, Patients, and Services. The analysis is done by observing and documenting the department and clusters with the methods of behavior mapping and shadowing. With these methods, individual travel paths, wayfinding challenges, workflow settings, and distances can be analyzed. Furthermore, path crossings of the same or different user groups can be acknowledged. Additionally, Study Phase C is subject to complementary data collection of the previous analysis settings. Using the information of expert knowledge, challenges and advantages in built environments, and documented behavior of all user groups is the aim of Study Phase C. Finally, the three Study Phases aim to combine aspects of environment, workflow, and behavior to derive planning requirements and design recommendations for future radiotherapy departments. Mahmood, F. J. (2021). The role of evidence-based design in informing health-care architects. Journal of Facilities Management, 19(2), 249–262. https://doi.org/10.1108/JFM-09-2020-0062 SP-0689 1+1=3, no delays, everything is on time! N. Hoffmans-Holtzer 1 1 Erasmus MC - Cancer Institute, University Medical Center Rotterdam, Radiotherapy, Rotterdam, The Netherlands Abstract Text Increasing cancer incidence (1), staff shortage (2) and the high incidence of burnout among radiation oncologists (RO), physicists and radiation technologists (RTT) (3-5) is putting many departments under strain while increasing healthcare costs and awareness of the environmental effects of healthcare are imposing additional restrictions on healthcare systems (6). To overcome a part of these problems, the field of optimization research (OR) could provide valuable tools to optimize radiotherapy (RT) processes (7). To date, however, only Vieira et al (8), reported on clinical implementation of an OR method in RT, which suggests a discrepancy between (mathematical) theory and clinical practice. Part of this discrepancy could be caused by the patient- Symposium: Our resources are limited! An insight on optimising radiotherapy resources for the future