Proof of concept of near real-time intra-fractional 3D monitoring of prostate position using a scheme based on the skeletonization of implanted marker images and recursive least squares approximation motion tracking Journal Article

  

Authors:	Kuo, H. C.; Della Biancia, C.; Damato, A. L.; Happersett, L.; Lim, S. B.; Cerviño, L. I.; Berry, S. L.
Article Title:	Proof of concept of near real-time intra-fractional 3D monitoring of prostate position using a scheme based on the skeletonization of implanted marker images and recursive least squares approximation motion tracking
Abstract:	Background: The on-board imaging system using monoscopic X-ray technology struggles to detect motion along the beam direction. This study presents a method that combines skeletonization for marker recognition with a Recursive Least Squares Approximation (RLSA) algorithm to convert 2D motion data into a 3D representation. Methods: Fiducial markers were represented as 2D lines through masking and skeletonization of paired-planar images, allowing for the construction of a 3D motion model. An iterative closest point (ICP) algorithm determined the 6D transformation from online to planning images. The accuracy of 3D motion estimation was evaluated across various angular separations (10°–170°) for both large (10 mm, 3°) and small (3 mm) marker offsets. The RLSA algorithm was validated against different motion drift patterns. Results: The marker recognition process was robust against varying contrast noise ratios. Mean errors of various angle separation tests in the X and Y directions were within 0.3 mm for large offsets and 0.2 mm for small offsets across all angular separations. With The RLSA applied at 10-° intervals during a 360-° gantry rotation, mean errors in the beam direction for continuous drift and low, intermediate, and high-frequency excursions were (0.2 ± 0.3) mm, (0.2 ± 0.3) mm, (0.4 ± 0.5) mm, and (0.4 ± 0.5) mm, respectively, with a maximum error of 1.3 mm across all excursion conditions. Conclusion: The proposed method demonstrates significant potential in effectively converting 2D motion into 3D and enabling real-time 3D motion tracking during intrafraction radiation therapy. © 2025 Associazione Italiana di Fisica Medica e Sanitaria
Keywords:	controlled study; radiotherapy; validation study; prostate; algorithm; clinical evaluation; radiography; online system; echo planar imaging; three-dimensional imaging; contrast to noise ratio; human; male; article; two-dimensional imaging; iterative closest point; data accuracy; prostate sbrt; marker guided radiation therapy; rlsa; skeletonization; skeletonization (imaging)
Journal Title:	Physica Medica
Volume:	135
ISSN:	1120-1797
Publisher:	Elsevier Inc.
Date Published:	2025-07-01
Start Page:	105009
Language:	English
DOI:	10.1016/j.ejmp.2025.105009
PROVIDER:	scopus
PUBMED:	40446391
DOI/URL:	https://www.scopus.com/inward/record.uri?eid=2-s2.0-105006654345&doi=10.1016%2fj.ejmp.2025.105009&partnerID=40&md5=8e0ccf57f5e697df9d38d786c1fd1ad9
Notes:	The MSK Cancer Center Support Grant (P30 CA008748) is acknowledged in the PDF. Corresponding MSK author is Hsiang-Chi Kuo -- Source: Scopus

https://synapse.mskcc.org/synapse/works/has_related_data_chk/226343