r-UNet: Leaf Position Reconstruction in Upstream Radiotherapy Verification

Autor: Lana Beck, Richard P. Hugtenburg, Jaap Velthuis, J. L. Pritchard, C. De Sio
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: De Sio, C, Velthuis, J J, Beck, L, Pritchard, J L & Hugtenburg, RI P 2020, ' r-UNet: Leaf Position Reconstruction in Upstream Radiotherapy Verification ', IEEE Transactions on Radiation and Plasma Medical Sciences . https://doi.org/10.1109/TRPMS.2020.2994648
DOI: 10.1109/TRPMS.2020.2994648
Popis: Monolithic active pixel sensor (MAPS) devices are an effective tool for upstream verification of intensity-modulated radiotherapy (IMRT) treatments. It is crucial to measure with high precision the positions of the multi-leaf collimators (MLCs) used to shape the beam in real time, in order to enhance the quality and safety of treatments. This article describes r-UNet, a deep learning-based solution for leaf position reconstruction. The model is used to analyze the high-resolution images produced by a Lassena MAPS device in order to automatically determine the leaf positions. Image segmentation and leaf position estimation are performed simultaneously in a multitask setting. r-UNet obtained an average Dice coefficient of 0.96 ± 0.03 for the reconstructed image masks in the held-out test set; whilst the mean squared error (MSE) resulting from the estimation of the MLC positions is 0.003 mm, with a resolution ranging between 45 and 53 $\mu \text{m}$ for leaf extensions between 1 and 35 mm. On unseen leaf positions, r-UNet yielded a single-leaf resolution between 54 and 88 $\mu \text{m}$ depending on the leaf extension, and an average MSE of 0.07 mm. These results were obtained using single frames of data collected at 34 frames/s.
Databáze: OpenAIRE