ESTRO 2022 - Abstract Book

S51

Abstract book

ESTRO 2022

Conclusion MRI and US yield similar prominence measurements (median absolute difference 0.3 mm) when tumour extent is visible on both modalities. However, in anteriorly located tumours, MRI measurements are more accurate, and using US for these tumours might lead to an underestimation of tumour diameter, possibly due to difficulty correctly positioning the ultrasound transducer. The extent of flat tumours can be difficult to assess on MRI, although, the distinction between tumour and healthy tissue may not be evident on US either. For these tumours, tumour measurements may be supported by fundoscopic imaging.

Poster Discussion: 02: Palliation, mixed sites

PD-0076 Predictive factors of severe radiation-induced lymphopenia in proton-treated patients

S. Pan 1 , P. Sitch 1 , S. Gaito 1 , A. McPartlin 2 , S. Sashidaran 3 , E. Smith 1 , G. Whitfield 1 , A. Abravan 4