ESTRO 2024 - Abstract Book

S5873

RTT - Service evaluation, quality assurance and risk management

ESTRO 2024

Senior Clinical Oncologist F was excluded from analysis given their low ICR number (n=1). There was no significant difference in ICR approvals between sCO reviewers (range 60-86%, p=0.27), sCO review and JR (69% vs 60%, p=0.34), 3D and 4D contouring (66% vs 65%, p=0.96) or number of reviews undertaken (range 12-42, p=0.22). There was a significant difference between PR and TRR approval (57% vs 83%, p=0.004). Seventy-four TVD UVs were observed, most frequently in domains of CTVB (which included editing for normal structures and elective lymph node irradiation, 35/74, 47%), PTV6000 (high dose ICRs only, 10/26, 38%), and ITV (4D ICRs only, 5/23, 22%). Accounting for submission heterogeneity and ICR number, the domains of identified UVs were subjectively comparable between sCOs, though meaningful statistical analysis was not possible.

Conclusion:

The move to a multi-reviewer RTQA approach did not result in significant differences in ICR outcome, and a similar distribution of UVs was observed between reviewers. This can be attributed to the incorporation of a clear RPGD and use of predefined UV criteria in to a robust, collaborative RTQA process, supporting its use in future trials. TRR approval was significantly higher than PR approval, which may be due to improvement in contouring standards, or a higher threshold for UV when RT had already commenced, and warrants further investigation.

Keywords: trials, reviewer variation, target definition

401

Mini-Oral

Cardiac SABR – an overview of challenges encountered with a new treatment two years on.

Marina Khan 1 , Caroline Sisodia 2 , Michelle Stenson 2 , George Ntentas 2,3,4 , Saima Naz 1 , Paula Treasure 1 , Shahreen Ahmad 5 1 Guys & St Thomas NHS Foundation Trust, Radiotherapy, London, United Kingdom. 2 Guys & St Thomas NHS Foundation Trust, Medical Physics, London, United Kingdom. 3 University of Oxford, Nuffield Department of Population Health, London, United Kingdom. 4 Kings College London, School of Biomedical Engineering & Imaging Sciences, London, United Kingdom. 5 Guys & St Thomas NHS Foundation Trust, Clinical Oncology, London, United Kingdom

Purpose/Objective:

SABR is a relatively new treatment option for the management of intractable ventricular tachycardia (VT). Radiation treatment for this benign condition is indicated after all conventional treatments have failed. Ventricular scarring from ischaemic damage can cause electrical re-entry and subsequent arrhythmia. Reported data from cardiac SABR (cSABR) treatments to date have shown up to 85% success rate in termination of VT events [1]. These patients have implantable cardioverter defibrillators. We review the service requirements and the complexities involved in