ESTRO 2023 - Abstract Book

S1847

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ESTRO 2023

Figure 2 plots median D and f values for all tumours and timepoints. D significantly increased from baseline to week 3 ( p = 0.013, paired t-test for patients scanned at both timepoints), while f showed no significant change ( p = 0.13). Median ADC from the conventional fit did not change significantly between baseline and week 3 ( p = 0.11). The fraction of tumour voxels favouring IVIM showed large inter-patient variability, which was maintained throughout treatment. Reliable contouring was hampered for some tumours at week 5 due to their small size.

Conclusion The diffusion coefficient from IVIM is sensitive to early therapy-induced changes in cervical tumours. However, the IVIM model is not favoured in all tumour voxels, demonstrating that model suitability should be evaluated as part of imaging biomarker validation.

PO-2070 Voxel-wise tumour response estimation from functional imaging and radiobiological model.

A. Lopez Medina 1 , M. Porta-Lorenzo 2 , M. Riveira-Martin 3 , I. Sanchez-Diaz 4 , R. Dorado-Dorado 1 , F.J. Salvador-Gomez 1 , Í. Nieto-Regueira 5 , V. Ochagavia-Galilea 5 , V. Muñoz-Garzón 5 1 Hospital do Meixoeiro - Galaria - SERGAS, Radiofisica y PR, Vigo, Spain; 2 University of Vigo, atlanTTic Research Center, Vigo, Spain; 3 Instituto de Investigación Sanitaria Galicia Sur , Medical Physics, Vigo, Spain; 4 Instituto de Investigación Sanitaria Galicia Sur, Medical Physics, Vigo, Spain; 5 Hospital do Meixoeiro - Galaria - SERGAS, Radioterapia, Vigo, Spain

Purpose or Objective