ESTRO meets Asia 2024 - Abstract Book

S253

Interdisciplinary – Radiobiology

ESTRO meets Asia 2024

Immune profiling of MOC2 tumours, 7 days post-treatment, was done using an 18-colour flow cytometry panel, which allowed detection of 16 innate and adaptive cell types. Immunohistochemical (IHC) staining of CD8 + and CD45 + leukocytes and CD31+ vasculature was performed on paraffin-embedded tumour sections. Tumour morphology was assessed using haematoxylin and eosin (H&E) staining.

Results:

USMB enhanced the response of murine HNC models to radiotherapy. Tumours treated with USMB, and 8 Gy exhibited a growth delay relative to the 8 Gy and untreated controls, increasing the median time for tumours to double in volume (to 300 mm 3 ), relative to 8 Gy and untreated control tumours, Figure 1.

Modulation of the TME was observed following the combination of USMB and radiotherapy. DCE-US imaging demonstrated that perfusion was increased, in comparison to either the 8 Gy or untreated controls, 7 days after treatment in both MOC1 and MOC2 tumours. Combined USMB and 8 Gy treatment also altered the profile of