ESTRO 2025 - Abstract Book

S4344

RTT - Treatment planning, OAR and target definitions

ESTRO 2025

fixed 10mm 2 ROI placed within healthy bladder tissue. Spearman correlations between TVs versus CDD and mean ADC versus CDD were analysed.

Results: Compared to baseline, TVs population mean on T2W increased 20% between fractions 6-15. TV population mean on DWI reduced by 33% (b150) and 37% (b500) after fraction 16 (Figure 1).

There was no consistent association between T2W TVs and CDD. In 80% of patients there was a negative association between DWI TVs and CDD and a positive associated between ADC and CDD (Table 1)

Intra observer TV variations were similar for all sequence types for all measurements compared to the STAPLE. Inter observer variations were greatest between 6-15 fractions.

Conclusion: This study suggests longitudinal TV change can be measured using ADC and CDD.

Keywords: Bladder ADC,DWI,

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Digital Poster Breast cancer: Anatomical parameters for optimizing personalized radiotherapy Francesco Cocco 1 , Maria Luisa Belli 1 , Elisabetta Parisi 2 , Simona Cima 2 , Donatella Arpa 2 , Irene Azzali 3 , Alessio Giuseppe Morganti 4,5 , Antonino Romeo 2 , Anna Sarnelli 1