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RT Journal Article
SR Electronic
T1 Segmentation of Brain Metastases Using Background Layer Statistics (BLAST)
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
DO 10.3174/ajnr.A7998
A1 Heyn, Chris
A1 Moody, Alan R.
A1 Tseng, Chia-Lin
A1 Wong, Erin
A1 Kang, Tony
A1 Kapadia, Anish
A1 Howard, Peter
A1 Maralani, Pejman
A1 Symons, Sean
A1 Goubran, Maged
A1 Martel, Anne
A1 Chen, Hanbo
A1 Myrehaug, Sten
A1 Detsky, Jay
A1 Sahgal, Arjun
A1 Soliman, Hany
YR 2023
UL http://www.ajnr.org/content/early/2023/09/21/ajnr.A7998.abstract
AB BACKGROUND AND PURPOSE: Accurate segmentation of brain metastases is important for treatment planning and evaluating response. The aim of this study was to assess the performance of a semiautomated algorithm for brain metastases segmentation using Background Layer Statistics (BLAST).MATERIALS AND METHODS: Nineteen patients with 48 parenchymal and dural brain metastases were included. Segmentation was performed by 4 neuroradiologists and 1 radiation oncologist. K-means clustering was used to identify normal gray and white matter (background layer) in a 2D parameter space of signal intensities from postcontrast T2 FLAIR and T1 MPRAGE sequences. The background layer was subtracted and operator-defined thresholds were applied in parameter space to segment brain metastases. The remaining voxels were back-projected to visualize segmentations in image space and evaluated by the operators. Segmentation performance was measured by calculating the Dice-Sørensen coefficient and Hausdorff distance using ground truth segmentations made by the investigators. Contours derived from the segmentations were evaluated for clinical acceptance using a 5-point Likert scale.RESULTS: The median Dice-Sørensen coefficient was 0.82 for all brain metastases and 0.9 for brain metastases of ≥10 mm. The median Hausdorff distance was 1.4 mm. Excellent interreader agreement for brain metastases volumes was found with an intraclass correlation coefficient = 0.9978. The median segmentation time was 2.8 minutes/metastasis. Forty-five contours (94%) had a Likert score of 4 or 5, indicating that the contours were acceptable for treatment, requiring no changes or minor edits.CONCLUSIONS: We show accurate and reproducible segmentation of brain metastases using BLAST and demonstrate its potential as a tool for radiation planning and evaluating treatment response.BLbackground layerBLASTBackground Layer StatisticsBMbrain metastasesDLdeep learningDSCDice-Sørensen coefficientHDHausdorff distanceICCintraclass correlation coefficientIQRinterquartile rangeSRSstereotactic radiosurgeryTHthreshold