ESTRO 2024 - Abstract Book

S5871

RTT - Service evaluation, quality assurance and risk management

ESTRO 2024

Of the 89 encounters included for analysis, only 27% of those proceeded to a full CT on their first attempt. The remainder required additional or repeat bowel or bladder preparation, or a laxative prescription and a repeat CT appointment. Bladder filling was the main factor in not proceeding to scan, followed by rectal gas. Those patients who required further preparation would likely to previously required a re-scan, or potentially have a less than optimal plan due to insufficient bladder volume or excessive rectal volume. The average mini scan dose was 93.86mGy-cm, and 536.36mGy-cm for full scans. Prostate patients made up the largest cohort at 66 patients. For this group, the figures were 89.23mGy-cm and 525.25mGy-cm for mini and full scans. 17 of the prostate patients proceeded to a full CT scan on their first attempt. So while these patients saw an increase in their overall dose without any direct benefit, there is a clear population benefit to the use of the mini scan. None of the cervix or endometrium patients included proceeded to a full scan on their initial attempt, while the anal canal and rectal patients had an even split between proceeding and not. Finally, comparison between the bladder volumes calculated using the equation and that contoured on Monaco showed a -1.8% difference in volume across 52 scans. 73% of bladder volumes calculated by the equation were within 25% of the actual bladder volume. The bladder volume equation was felt to be a comparable surrogate for contoured bladder volumes, allowing sufficiently accurate assessment of bladder volumes on the mini scans, and preventing the acquisition of full scans without an acceptable bladder volume.

Conclusion:

The study validated the use of mini-scans in pelvic radiotherapy patients within the department. The mini-scans have now been implemented as standard practice for patients attending for pelvic radiotherapy.

Keywords: Justification, CT, Quality Improvement

389

Poster Discussion

Dose escalation in oesophageal cancer: comparing inter-reviewer variation within the UK SCOPE2 trial

Jonathan Helbrow 1 , Tom Crosby 2 , Owen Nicholas 1,3 , Ganesh Radhakrishna 4 , John Graby 5,6 , Geraint J Lewis 7 , Samantha Cox 2 , Maria Hawkins 8 , Rhiannon M Evans 2 , Sarah Gwynne 1,3 1 South West Wales Cancer Centre, Clinical Oncology, Swansea, United Kingdom. 2 Velindre Cancer Centre, Clinical Oncology, Cardiff, United Kingdom. 3 Swansea University, School of Medicine, Swansea, United Kingdom. 4 The Christie Cancer Centre, Clinical Oncology, Manchester, United Kingdom. 5 University of Bath, Department of Health, Bath, United Kingdom. 6 Royal United Hospitals Bath NHS Foundation Trust, Cardiology, Bath, United Kingdom. 7 Velindre Cancer Centre, Medical Physics, Cardiff, United Kingdom. 8 University College London, Medical Physics and Biomedical Engineering, London, United Kingdom

Purpose/Objective: