ESTRO 2024 - Abstract Book

S537

Clinical - Breast

ESTRO 2024

Conclusion:

Surface-guided radiation therapy (SGRT) has been established as a powerful system for patient positioning and control, especially for left-sided breast cancer patients. Interestingly, mean AlignRT shifts were minimal and stable, with an estimate of 0.3 cm, along total duration of treatment. Many questions arise regarding the reliability of SGRT solely and the need to determine a corrective threshold at the first CBCT to plan additionnal CBCT. Further analysis on larger cohorts are neeeded to confirm these observations and to potentially reduce the frequency or the use of CBCT.

Keywords: repositioning, surface-based monitoring

1141

Digital Poster

Review of supraclavicular radiotherapy field and surgical clip position post axillary node clearance

Chii Yang Kuah 1 , Saima Nazir 1 , Dorothy Gujral 1 , Paul Thiruchelvam 2 , Susan Cleator 1

1 Charing Cross Hospital, Clinical Oncology, London, United Kingdom. 2 Charing Cross Hospital, Breast Surgery, London, United Kingdom

Purpose/Objective:

The management of the involved axilla in breast cancer is an evolving field. Whilst there is a trend towards surgical de-escalation, many patients require axillary node clearance (ANC) and are advised to receive post-operative radiotherapy to the upper part of the axillary lymph node chain and/ or the supraclavicular fossa (SCF). There is debate as to what constitutes an appropriate level of axillary clearance in a given case and there is likely inter surgeon variability. In general, it is thought that the radiation volume delivered to the upper axilla/ SCF should ’match’ the surgical field. There is no clear guidance as to how a radiation oncologist should judge the level of dissection to define SCF field placement and inter-oncologist variability in this regard is likely. We set out to document surgical and SCF radiotherapy fields and the relation thereof in a cohort of patients undergoing post-ANC nodal radiotherapy.