Abstract
PurposeThe number of pencil beam scanned proton therapy (PBS‐PT) facilities equipped with cone‐beam computed tomography (CBCT) imaging treating thoracic indications is constantly rising. To enable daily internal motion monitoring during PBS‐PT treatments of thoracic tumors, we assess the performance of Motion‐Aware RecOnstructiOn method using Spatial and Temporal Regularization (MA‐ROOSTER) four‐dimensional CBCT (4DCBCT) reconstruction for sparse‐view CBCT data and a realistic data set of patients treated with proton therapy.MethodsDaily CBCT projection data for nine non‐small cell lung cancer (NSCLC) patients and one SCLC patient were acquired at a proton gantry system (IBA Proteus® One). Four‐dimensional CBCT images were reconstructed applying the MA‐ROOSTER and the conventional phase‐correlated Feldkamp‐Davis‐Kress (PC‐FDK) method. Image quality was assessed by visual inspection, contrast‐to‐noise ratio (CNR), signal‐to‐noise ratio (SNR), and the structural similarity index measure (SSIM). Furthermore, gross tumor volume (GTV) centroid motion amplitudes were evaluated.ResultsImage quality for the 4DCBCT reconstructions using MA‐ROOSTER was superior to the PC‐FDK reconstructions and close to FDK images (median CNR: 1.23 [PC‐FDK], 1.98 [MA‐ROOSTER], and 1.98 [FDK]; median SNR: 2.56 [PC‐FDK], 4.76 [MA‐ROOSTER], and 5.02 [FDK]; median SSIM: 0.18 [PC‐FDK vs FDK], 0.31 [MA‐ROOSTER vs FDK]). The improved image quality of MA‐ROOSTER facilitated GTV contour warping and realistic motion monitoring for most of the reconstructions.ConclusionMA‐ROOSTER based 4DCBCTs performed well in terms of image quality and appear to be promising for daily internal motion monitoring in PBS‐PT treatments of (N)SCLC patients.
Highlights
In recent years, cone-beam computed tomography (CBCT) acquisition has become available at pencil beam scanned proton therapy (PBS-PT) facilities with the main purpose of daily positioning and anatomy verification.[1]
Visual inspection of the images as well as the image quality measures revealed that the MA-ROOSTER reconstructed images were close in image quality to the FDK images (Figs. 2 and 3)
This was more apparent for the patient group without metallic objects, as the metal hampered the image quality of both MA-ROOSTER and phase-correlated algorithm of Feldkamp-Davis-Kress (PC-FDK) reconstructions
Summary
Cone-beam computed tomography (CBCT) acquisition has become available at pencil beam scanned proton therapy (PBS-PT) facilities with the main purpose of daily positioning and anatomy verification.[1] As PBS-PT has been extended for an increasing number of PT facilities totreatment of moving targets, daily motion monitoring in treatment position would be of added value This would require a four-dimensional (4D) reconstruction method where currently only three-dimensional cone-beam computed tomography (3DCBCT) reconstruction software is commercially available for proton CBCT installations. For phantom data with known motion amplitudes, this method has shown to be promising to implement for scanned proton gantry systems.[16]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
