ESTRO 2025 - Abstract Book

S4289

RTT - Service evaluation, quality assurance and risk management

ESTRO 2025

Conclusion: Our study highlights the ambiguities of measuring patient delay and investigates three approaches to depict the waiting time. To draw meaningful inferences about waiting times and departmental delays in RT without including factors outside a department’s control, our results suggest focusing on prioritized treatment start dates rather than referral dates. As future work, we plan to explore diagnosis-specific delays further and build a strategy that can standardize department-specific waiting list statistics.

Keywords: Patient delays, target date, imbalance

References: 1. Chen, Zheng et al. “The relationship between waiting time for radiotherapy and clinical outcomes: a systematic review of the literature.” Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology vol. 87,1 (2008): 3-16. 2. Babashov V., et al. Reducing Patient Waiting Times for Radiation Therapy and Improving the Treatment Planning Process: a Discrete-event Simulation Model (Radiation Treatment Planning) Clin Oncol (R Coll Radiol) 2017;29(6):385– 391. 3. Thomsen, Mette Skovhus, and Ole Nørrevang. “A model for managing patient booking in a radiotherapy department with differentiated waiting times.” Acta oncologica (Stockholm, Sweden) vol. 48,2 (2009)

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Digital Poster Continuous quality improvement approach for dose optimisation in radiotherapy computed tomography scanning Claire Harman 1 , Derry McCarthy 1 , Christopher Walker 2 1 Department of Radiation Oncology, Cork University Hospital, Cork, Ireland. 2 Department of Medical Physics, Cork University Hospital, Cork, Ireland Purpose/Objective: High quality computed tomography (CT) images are essential to precisely define tumour volumes and organs at risk in radiotherapy planning. Diagnostic or dose reference levels (DRLs) are a measure by which CT dose levels (CTDIvol) are recorded and monitored in radiotherapy practice. DRLs are metrics produced by the scanner to quantify the radiation output during a scan. They allow for identification of unjustifiably high radiation doses by applying a dose threshold above which investigation is required (1). Ireland does not currently have national DRLs to audit practice against. In order to promote good practice and comply with statutory requirements in Ireland (2), establishment of local DRLs (LDRLs) and audit is performed annually as a quality improvement plan in Cork University Hospital Cancer Centre (CUH). Material/Methods: • Performing retrospective analysis of CT scan data performed over a one-year period. • Establishing local DRLs using dose length product (DLP) per scanned anatomical site. • Investigating any variances between annual data and that of the previous year, to ensure adequate optimisation and good practice are adhered to. GEs Dosewatch® software is used on the radiotherapy CT scanners, with full DICOM CT scan header information exported to the Dosewatch® server. The continuous quality improvement approach is applied, using the Pareto principle. Any notable variances between DLPs from year to year are reported, with 20% of the protocols and any concerning or large variations investigated.