ESTRO 2024 - Abstract Book

S2224

Clinical - Upper GI

ESTRO 2024

region. Three of five patients whose Child-Pugh class changed with at least a 2-point score increment also exhibited grade 3+ liver toxicity.

Conclusion:

For the considered cohort of patients, HyTEC recommended constraints were not validated, potentially because of the sample size and number of toxicities. Patients with smaller normal liver volumes were more likely to develop liver toxicity. Concurrent or prior radiotherapy appears to be a risk factor. However, a larger sample is needed to demonstrate this relationship.

Keywords: Liver SBRT, toxicity

References:

1. Miften.M, Vinogradskiy Y, Moiseenko V, Grimm J, Yorke E, Jackson A, Tome WA, Ten Haken R, Ohri N, Mendez Romero A, Goodman KA, Marks LB, Kavanagh B, Dawson LA. Radiation dose-volume effects for liver SBRT. International Journal of Radiation Oncology Biology Physics, 2021, 110, 196-205

2086

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Interobserver variation in target volume delineation for gastric radiotherapy using CT and MRI

Amy N Case 1,2 , Becky Slinger 1 , Kieran Foley 3,4,5 , George Joseph 4 , Emiliano Spezi 6 , Jonathan Helbrow 1 , Hayley Hutchings 2 , Owen Nicholas 1,2 , Sarah Gwynne 1,2 1 South West Wales Cancer Centre, Swansea Bay University Health Board, Swansea, United Kingdom. 2 Swansea University, Swansea University Medical School, Swansea, United Kingdom. 3 Cwm Taf Morgannwg UHB, Royal Glamorgan Hospital, Llantrissant, United Kingdom. 4 Velindre Cancer Centre, Radiology, Cardiff, United Kingdom. 5 Cardiff University, School of Medicine, Cardiff, United Kingdom. 6 Cardiff University, School of Engineering, Cardiff, United Kingdom

Purpose/Objective:

In the UK, radiotherapy (RT) for gastric adenocarcinoma is currently only recommended in the post-operative and palliative setting, but is being evaluated in the pre-operative setting by a growing number of trials. 1,2

Interobserver variability (IOV) of target volume delineation (TVD) has been reported in the pre- and post-operative setting, but with focus on CTV, evaluating whole stomach and elective nodal regions, or surgical bed and nodal regions at risk, respectively. 3-9 To date there are no published studies reporting IOV in delineation of the primary tumour (GTVp), or the use of imaging other than CT to aid TVD.