Target localization and real-time tracking using the Calypso 4D localization system in patients with localized prostate cancer

Willoughby, Twyla R.; Kupelian, Patrick A.; Pouliot, Jean; Shinohara, Katsuto; Aubin, M; Roach, Mack; Skrumeda, Lisa L.; Balter, James M.; Litzenberg, Dale W.; Hadley, Scott; Wei, John T.; Sandler, Howard M.

doi:10.1016/j.ijrobp.2006.01.050

Cited by 398 publications

(292 citation statements)

References 15 publications

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“…Our results for translations are similar to those published by other authors in phantom and patient studies 13, 15, 16, 18. Table 3 shows our mean differences and standard deviations for translations in the lateral, vertical and longitudinal directions, and for the vector translation, in comparison with the results of these studies.…”

Section: Discussionsupporting

confidence: 89%

“…The results of our study confirm the findings of others that Calypso gives a similar level of accuracy for patient translations as current best practice radiographic imaging 13, 15, 16. In addition, we now have increased confidence in the accuracy of the rotational information provided by Calypso.…”

Section: Discussionsupporting

confidence: 89%

“…extended their phantom study to a cohort of 259 patient measurements, again demonstrating good correlation between kV orthogonal imaging and Calypso. The results of Willoughby et al 16. were similar, with a mean 3D distance vector difference of 1.5 mm between Calypso and orthogonal kV‐imaging.…”

Section: Introductionmentioning

confidence: 59%

“…Patient and animal studies have also demonstrated strong correlation between transponder‐based systems and radiographic systems 5, 11, 13, 15, 16, 17, 18. Foster et al 15.…”

Section: Introductionmentioning

confidence: 99%

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Comparison between electromagnetic transponders and radiographic imaging for prostate localization: A pelvic phantom study with rotations and translations

Hamilton

McKenzie

Perkins

2017

J Applied Clin Med Phys

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The aim of this study was to evaluate the differences in target localization between Calypso®, kV orthogonal imaging and cone‐beam computed tomography (CBCT) for combined translations and rotations of an anthropomorphic pelvic phantom. The phantom was localized using all three systems in 50 different positions, with applied translational and rotational offsets randomly sampled from representative normal distributions of prostate motion. Lin's concordance correlation coefficient (ρc) and 95% confidence intervals were calculated to assess the agreement between the localization systems. Mean differences and difference vectors between the three systems were also calculated. Agreement between systems for lateral, vertical, and longitudinal translations was excellent, with ρc values of greater than 0.98 between all three systems in all axes. There was excellent agreement between the systems for rotations around the lateral axis (pitch) (ρc > 0.99), and around the vertical axis (yaw) (ρc > 0.97). However, somewhat poorer agreement for rotations around the longitudinal axis (roll) was observed, with the lowest correlation observed between Calypso and kV orthogonal imaging (ρc = 0.895). Mean differences between the phantom position reported by Calypso and the radiographic systems were less than 1 mm and 1° for all translations and rotations. The results for translations are consistent with the publications of previous authors. There is no comparable published data for rotations. While there is lower correlation between the three systems for roll than for the other angles, the mean differences in reported rotations are not clinically significant.

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Section: Discussionsupporting

confidence: 89%

Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 59%

“…Patient and animal studies have also demonstrated strong correlation between transponder‐based systems and radiographic systems 5, 11, 13, 15, 16, 17, 18. Foster et al 15.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Comparison between electromagnetic transponders and radiographic imaging for prostate localization: A pelvic phantom study with rotations and translations

Hamilton

McKenzie

Perkins

2017

J Applied Clin Med Phys

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“…Tracking can be direct via transmission X‐ray imaging or directly determining the position of the electromagnetic emitters, or indirect via correlation models to a surrogate such as the patient surface. Similar to the error measurement of TRE, point tracking methods are believed to achieve accuracy in the range of 2 mm 37 , 38 , 39 . A recent method using 1D MRI pencil‐beam navigators to track tissue motion reported accuracy within 1.5 mm in one case of kidney motion (40) .…”

Section: Discussionmentioning

confidence: 99%

A comparative study of automatic image segmentation algorithms for target tracking in MR‐IGRT

Feng

Kawrakow

Olsen

et al. 2016

J Applied Clin Med Phys

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On‐board magnetic resonance (MR) image guidance during radiation therapy offers the potential for more accurate treatment delivery. To utilize the real‐time image information, a crucial prerequisite is the ability to successfully segment and track regions of interest (ROI). The purpose of this work is to evaluate the performance of different segmentation algorithms using motion images (4 frames per second) acquired using a MR image‐guided radiotherapy (MR‐IGRT) system. Manual contours of the kidney, bladder, duodenum, and a liver tumor by an experienced radiation oncologist were used as the ground truth for performance evaluation. Besides the manual segmentation, images were automatically segmented using thresholding, fuzzy k‐means (FKM), k‐harmonic means (KHM), and reaction‐diffusion level set evolution (RD‐LSE) algorithms, as well as the tissue tracking algorithm provided by the ViewRay treatment planning and delivery system (VR‐TPDS). The performance of the five algorithms was evaluated quantitatively by comparing with the manual segmentation using the Dice coefficient and target registration error (TRE) measured as the distance between the centroid of the manual ROI and the centroid of the automatically segmented ROI. All methods were able to successfully segment the bladder and the kidney, but only FKM, KHM, and VR‐TPDS were able to segment the liver tumor and the duodenum. The performance of the thresholding, FKM, KHM, and RD‐LSE algorithms degraded as the local image contrast decreased, whereas the performance of the VP‐TPDS method was nearly independent of local image contrast due to the reference registration algorithm. For segmenting high‐contrast images (i.e., kidney), the thresholding method provided the best speed (<1 ms) with a satisfying accuracy (Dice=0.95). When the image contrast was low, the VR‐TPDS method had the best automatic contour. Results suggest an image quality determination procedure before segmentation and a combination of different methods for optimal segmentation with the on‐board MR‐IGRT system.PACS number(s): 87.57.nm, 87.57.N‐, 87.61.Tg

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Tumor Targeting: Image‐Guided and Adaptive Radiation Therapy

2016

Hendee's Radiation Therapy Physics

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Target localization and real-time tracking using the Calypso 4D localization system in patients with localized prostate cancer

Cited by 398 publications

References 15 publications

Comparison between electromagnetic transponders and radiographic imaging for prostate localization: A pelvic phantom study with rotations and translations

Comparison between electromagnetic transponders and radiographic imaging for prostate localization: A pelvic phantom study with rotations and translations

A comparative study of automatic image segmentation algorithms for target tracking in MR‐IGRT

Tumor Targeting: Image‐Guided and Adaptive Radiation Therapy

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