ESTRO 2024 - Abstract Book

S5094

Physics - Radiomics, functional and biological imaging and outcome prediction

ESTRO 2024

separated from background FLT uptake in healthy tissues (p > 0.05). The ratio of peripheral/central gross tumour volume (GTV) IVIM parameters, as well as the contrast between GTV-ADC and Dt versus contra-lateral healthy tissue and edema parameters, also show promise in assisting TP/RN differentiation ( see Figure 1, below ). To increase result confidence, expanding patient accrual to achieve a larger sample size (n) is required.

Figure 1: PET/MRI datasets co-acquired from a single patient via various imaging modalities and perfusion assessment methodologies . The localization of the lesion ROI is highlighted in A). Same-slice image presented for A) PET/MR Ax fusion, B) t1w MPRAGE planning MRI, C) t2w SPACE MRI D) Dynamic PET k3 parametric image, E) Dynamic PET k2 parametric image, F) Dynamic PET Vt parametric image, G) Raw DWI MRI, H) DWI MRI, true diffusion fraction (Dt), I) DWI MRI, perfusion fraction (Dp).

Conclusion:

Our study examines the feasibility of FLT-PET and DWI-MRI protocols in classifying TP/RN. Direct comparison of co acquired PET/DWI-MRI differentiation accuracy can advise future development of image-based protocols to favour patient stratification. Although effective treatments exist for both TP and RN cases, accurate differentiation is crucial due to the substantial divergence in treatment approaches per clinical response 7,8 .

Keywords: Functional MRI, Brain metastases, AI classfication

References:

1. Patel, T. R. et al. A Comprehensive Review of MR Imaging Changes following Radiosurgery to 500 Brain Metastases. Am. J. Neuroradiol. 32, 1885–1892 (2011). 2. Hartgerink, D. et al. LINAC based stereotactic radiosurgery for multiple brain metastases: guidance for clinical implementation. Acta Oncol. Stockh. Swed. 58, 1275–1282 (2019). 3. Sacks, P. & Rahman, M. Epidemiology of Brain Metastases. Neurosurg. Clin. N. Am. 31, 481–488 (2020). 4. Lauko, A., Rauf, Y. & Ahluwalia, M. S. Medical management of brain metastases. Neuro-Oncol. Adv. 2, vdaa015 (2020).