ESTRO 2024 - Abstract Book

S2496

Clinical - Urology

ESTRO 2024

Conclusion:

Clear patterns can be observed in the daily MRL image series. Volume increases are known to occur and are likely caused by radiation-induced oedema[3]. The T2w intensity reduction is thought to be caused by changes in T2 and T2* of the prostate tissue due to atrophy of the acinar tubes[4]. Earlier analyses in prostate[5] did report similar trends on intensity but, in contrast to our findings, not in ADC. Our ADC changes (decrease in diffusion restriction) could reflect tumour cell death. We conclude that the MRL workflow is excellently suited to systematically monitor these changes. Our future work will investigate the correlation between GTV-ADC changes and clinical and dosimetric parameters.

Keywords: MR-Linac, ADC, T2w

References:

[1] Isensee, F., Jaeger, P. F., Kohl, S. A., Petersen, J., & Maier-Hein, K. H. (2021). nnU-Net: a self-configuring method for deep learning-based biomedical image segmentation. Nature methods, 18(2), 203-211.

[2] Klein, S., Staring, M., Murphy, K., Viergever, M.A., Pluim, J.P.W. (2010). Elastix: a toolbox for intensity based medical image registration, IEEE Transactions on Medical Imaging, 29(1), 196-205

[3] Gunnlaugsson, A., Kjellén, E., Hagberg, O. et al. (2014). Change in prostate volume during extreme hypo fractionation analysed with MRI. Radiat Oncol 9, 22.

[4] Iczkowski, K.A. (2009). Effect of Radiotherapy on Non-Neoplastic and Malignant Prostate. The Open Pathology Journal, 3, 64-73

[5] Van Schie, M.A., Van Houdt, P.J., Ghobadi, G., Pos, F.J., Walraven, I., De Boer, H.C.J., Van den Berg, C.A.T., Smeenk, R.J., Kerkmeijer, L.G.W. and Van der Heide, U.A. (2019). Quantitative MRI Changes During Weekly Ultra Hypofractionated Prostate Cancer Radiotherapy With Integrated Boost. Front. Oncol. 9:1264