Evaluation of a lung tumor autocontouring algorithm for intrafractional tumor tracking using low-field MRI: A phantom study

Yun, Jihyun; Yip, Eugene; Wachowicz, Keith; Rathee, S; MacKenzie, M; Robinson, Don; Fallone, B. G.

doi:10.1118/1.3685578

Cited by 36 publications

(45 citation statements)

References 38 publications

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“…They suggest addressing out-of-plane motion by surrogate tracking of the diaphragm. Yun et al (2012b) investigated the use of an intra-fractional lung tumor auto-contouring algorithm for a phantom study using sagittal cine-MRI planes. Yun et al (2012a) describes how the auto-contouring algorithm of Yun et al (2012b) can be extended with an artificial neural network-based motion prediction algorithm.…”

Section: Introductionmentioning

confidence: 99%

“…Yun et al (2012b) investigated the use of an intra-fractional lung tumor auto-contouring algorithm for a phantom study using sagittal cine-MRI planes. Yun et al (2012a) describes how the auto-contouring algorithm of Yun et al (2012b) can be extended with an artificial neural network-based motion prediction algorithm. Ries et al (2010) performed 3D target tracking by combining 2D-plane imaging with prospective slice tracking based on pencil-beam navigator sequences.…”

Section: Introductionmentioning

confidence: 99%

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Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

et al. 2013

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The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-treatment 3D breath-hold scan, extracting a 3D target template and performing template matching between this 3D template and pairs of orthogonal 2D cine-MRI planes intersecting the target motion path. For a 60 s free-breathing series of orthogonal cine-MRI planes, we demonstrate that the method was capable of accurately tracking the respiration related 3D motion of the left kidney. Quantitative evaluation of the method using a dataset designed for this purpose revealed a translational error of 1.15 mm for a translation of 39.9 mm. We have demonstrated how interleaved acquired, orthogonal cine-MRI planes can be used for online tracking of soft-tissue target volumes.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

et al. 2013

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“…The development of hybrid radiotherapy/MR imaging technologies 1, 2 potentially allows for real time, intrafractional MR guided radiation delivery. [3][4][5] This type of treatment is of particular interest in tumor sites with large intrafractional motion, such as in the lung. 4,6 We have proposed for a treatment scheme for the system, 3 requiring the acquisition of real time MR images in which the tumor shape is automatically segmented by our contouring software.…”

Section: Introductionmentioning

confidence: 99%

“…[3][4][5] This type of treatment is of particular interest in tumor sites with large intrafractional motion, such as in the lung. 4,6 We have proposed for a treatment scheme for the system, 3 requiring the acquisition of real time MR images in which the tumor shape is automatically segmented by our contouring software. The extracted position and shape of the tumor, determined by the software, is used to direct the multileaf collimator (MLC), shaping the radiation beam to the desired tumor position.…”

Section: Introductionmentioning

confidence: 99%

“…In order to benefit from real time image guidance, the system's delay time (time required for image acquisition, image reconstruction, tumor autocontouring, and MLC collimation) should be kept under 0.5 s, according to the AAPM's task group report on respiratory management, TG-76. 6 We have previously shown 3 that fast MR sequences such as balanced steady state free precession (bSSFP) can acquire a single 2D slice at 4 frames/s at modest spatial resolutions. However, accelerated MR acquisition can benefit tumor tracking in several ways: (1) an increase in imaging frame rate, (2) an increase in image resolution, (3) an ability to image beyond two dimensions while maintaining the necessary frame rate.…”

Section: Introductionmentioning

confidence: 99%

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Prior data assisted compressed sensing: A novel MR imaging strategy for real time tracking of lung tumors

et al. 2014

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The PDACS method can potentially improve the real time tracking of moving tumors by significantly increasing MRI's data acquisition speeds. In 3T images, the PDACS method does provide a benefit over the other two methods in terms of both the overall image quality and the ability to accurately and automatically contour the tumor shape. MRI's data acquisition may be accelerated using the simpler viewsharing strategy at the lower, 0.5T magnetic field, as the marginal benefit of the PDACS method may not justify its additional reconstruction times.

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Film measurement and analytical approach for assessing treatment accuracy and latency in a magnetic resonance‐guided radiotherapy system

Okamoto

Nakamura

et al. 2023

J Applied Clin Med Phys

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We measure the dose distribution of gated delivery for different target motions and estimate the gating latency in a magnetic resonance-guided radiotherapy (MRgRT) system. Method: The dose distribution accuracy of the gated MRgRT system (MRIdian, Viewray) was investigated using an in-house-developed phantom that was compatible with the magnetic field and gating method. This phantom contains a simulated tumor and a radiochromic film (EBT3, Ashland, Inc.). To investigate the effect of the number of beam switching and target velocity on the dose distribution, two types of target motions were applied. One is that the target was periodically moved at a constant velocity of 5 mm/s with different pause times (0, 1, 3, 10, and 20 s) between the motions. During different pause times, different numbers of beams were switched on/off. The other one is that the target was moved at velocities of 3, 5, 8, and 10 mm/s without any pause (i.e., continuous motion). The gated method was applied to these motions at MRIdian, and the dose distributions in each condition were measured using films. To investigate the relation between target motion and dose distribution in the gating method, we compared the results of the gamma analysis of the calculated and measured dose distributions. Moreover, we analytically estimated the gating latencies from the dose distributions measured using films and the gamma analysis results. Results:The gamma pass rate linearly decreased with increasing beam switching and target velocity. The overall gating latencies of beam-hold and beam-on were 0.51 ± 0.17 and 0.35 ± 0.05 s, respectively. Conclusions: Film measurements highlighted the factors affecting the treatment accuracy of the gated MRgRT system. Our analytical approach, employing gamma analysis on films, can be used to estimate the overall latency of the gated MRgRT system.

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Evaluation of a lung tumor autocontouring algorithm for intrafractional tumor tracking using low-field MRI: A phantom study

Cited by 36 publications

References 38 publications

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

Prior data assisted compressed sensing: A novel MR imaging strategy for real time tracking of lung tumors

Film measurement and analytical approach for assessing treatment accuracy and latency in a magnetic resonance‐guided radiotherapy system

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