PhD Scientific Days 2023

Clinical Medicine - Posters I

Pre-embolization Volumetry of Uterine Leiomyomas using Self-adapting Machine Learning Frameworks

Text of the abstract

Introduction: Uterine fibroid embolization (UFE) is a minimally invasive alternative to hysterectomy. Artificial intelligence (AI) algorithms, such as convolutional neural networks (CNN), have been successfully applied to the automated measurement of tumour volumes. In contrast, in the field of fibroid volumetry results are scarce, as AI algorithms require time and resources to be properly tuned.

Aims: We aimed to assess the potential of two self-adapting CNN frameworks (2D and 3D nnU-Net) for performing fully automated uterine fibroid segmentation.

Method: 130 axial pelvic T2-weighted SPAIR MRI scans of UFE patients were retrospectively retrieved, and the fibroids were manually segmented. The fibroid volumes and segmentation maps were processed with nnU-Net: first, the algorithm determined the optimal preprocessing, network architecture, training, and postprocessing steps, afterwards, it performed training via 5-fold cross-validation (CV), the training/validation ratio for 48 images was 4:1. After each round of CV, the trained models were combined into an ensemble, and evaluated on a hold-out test set of 40 cases. The overlap between the predicted and manually segmented volumes were measured by calculating the Dice scores (DSC), Jaccard-coefficients (JC), and average Hausdorff distances (aHD).

Results: The difference between the fibroid volume calculated from the manually segmented masks and the masks predicted by 2D nnU-Net were -14,23±56,13 cm3 (mean±SD), by 3D nnU-Net were 15,11±39,27 cm3; Pearson’s correlation coefficient was 0.975 and 0.990; DSC of 0,764±0,182 and 0,854±0,128; Jaccard-coefficient of 0,647±0,201 and 0,756±0,141; and aHD of 1,649±2,683 and 1,002±2,379 mm were achieved.

Conclusions: State-of-the-art machine learning methods, such as 3D nnU-Net, are well applicable for automated volume measurement of uterine fibroids despite the significant variations in size and number.

Funding: The results publicised in this work was reached with the sponsorship of Gedeon Richter Talentum Foundation in framework of Gedeon Richter Excellence PhD Scholarship of Gedeon Richter.