Quality assurance of U.S.‐guided external beam radiotherapy for prostate cancer: Report of AAPM Task Group 154

Molloy, J; Chan, Grace; Markovic, Alexander; McNeeley, Shawn; Pfeiffer, D; Salter, Bill J.

doi:10.1118/1.3531674

Cited by 41 publications

(27 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The BAT® system (Best Nomos, PA, USA) uses transabdominal ultrasound (TAUS) imaging to provide daily corrections to inter-fraction prostate variations by comparing the prostate position with the planning CT scan contour (Lattanzi et al 2000). The Clarity® system (Elekta, Stockholm, Sweden) provides inter-fraction setup corrections adhering to the AAPM TG154 recommendation that US guidance should use US images as reference rather than CT, by integrating US at the patient simulation stage (Molloy et al 2011). The Clarity device, which uses a 5 MHz 3D mechanically-swept probe, is being further developed to provide intra-fraction monitoring with images acquired via the perineum (TPUS) with a 2.5 second imaging period (Lachaine and Falco 2013).…”

mentioning

confidence: 99%

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

O’Shea¹,

Garcia²,

Rosser³

et al. 2014

Phys. Med. Biol.

View full text Add to dashboard Cite

This study investigates the use of a mechanically-swept 3D ultrasound (3D-US) probe for soft-tissue displacement monitoring during prostate irradiation with emphasis on quantifying the accuracy relative to CyberKnife® x-ray fiducial tracking. An US phantom, implanted with x-ray fiducial markers was placed on a motion platform and translated in 3D using 5 real prostate motion traces acquired using the Calypso system. Motion traces were representative of all types of motion as classified by studying Calypso data for 22 patients. The phantom was imaged using a 3D swept linear-array probe (to mimic trans-perineal imaging) and, subsequently, the kV x-ray imaging system on CyberKnife. A 3D cross-correlation block matching algorithm was used to track speckle in the ultrasound data. Fiducial and US data were each compared with known phantom displacement. Trans-perineal 3D-US imaging could track superior-inferior (SI) and anterior-posterior (AP) motion to ≤ 0.81 mm root-mean-square error (RMSE) at a 1.7 Hz volume rate. The maximum kV x-ray tracking RMSE was 0.74 mm, however the prostate motion was sampled at a significantly lower imaging rate (mean: 0.04 Hz). Initial elevational (RL) US displacement estimates showed reduced accuracy but could be improved (RMSE < 2.0 mm) using a correlation threshold in the ultrasound tracking code to remove erroneous inter-volume displacement estimates. Mechanically-swept 3D-US can accurately track the major components of intra-fraction prostate motion accurately but exhibits some limitations. The largest US RMSE was for elevational (right-left) motion. For the AP and SI axes, accuracy was sub-millimetre. It may be feasible to track prostate motion in 2D only. 3D-US also has potential for improvement for high tracking accuracy in all circumstances. It would be advisable to use US in conjunction with a small (~ 2.0 mm) centre-of-mass displacement threshold in which case it would be possible to take full advantage of the accuracy and high imaging rate capability.

show abstract

mentioning

confidence: 99%

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

O’Shea¹,

Garcia²,

Rosser³

et al. 2014

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…The American Association of Physicists in Medicine stresses that clinical ultrasound training of the operators is of utmost prominence. 20 The A-US transducer used in this study inherits identical characteristics as the real-time monitoring autoscan, 14 initially designed for transperineal prostate tracking, but was modified to perform transabdominal imaging. Since the system was not provided with a robotic arm, and our software was not adapted for real-time monitoring, the probe was incapable of real-time tracking of the uterus and thus was unable to determine intrafractional motion, which otherwise would be an interesting field to investigate.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of uterine ultrasound imaging in cervical radiotherapy; a comparison of autoscan and conventional probe

Baker¹,

Cooper²,

Behrens³

2016

BJR

View full text Add to dashboard Cite

“…An example of this methodology is the Clarity system (Elekta, Stockholm, Sweden). 4,5 Although intramodal alignment at the treatment stage is less sensitive to errors compared to the interimaging modality discrepancies 6 in intermodality systems, the complete workflow contains extra registration steps and procedures that may increase the error susceptibility. Because the actual treatment planning is based on a reference CT image, and not on a US ref image, the accuracy of intramodality image guidance systems depends on the correct intermodality registration of the patient's US ref scan and the planning CT.…”

Section: Introductionmentioning

confidence: 99%

Consequences of Intermodality Registration Errors for Intramodality 3D Ultrasound IGRT

Meer

Seravalli

Fontanarosa

et al. 2016

Technol Cancer Res Treat

View full text Add to dashboard Cite

Intramodality ultrasound image-guided radiotherapy systems compare daily ultrasound to reference ultrasound images. Nevertheless, because the actual treatment planning is based on a reference computed tomography image, and not on a reference ultrasound image, their accuracy depends partially on the correct intermodality registration of the reference ultrasound and computed tomography images for treatment planning. The error propagation in daily patient positioning due to potential registration errors at the planning stage was assessed in this work. Five different scenarios were simulated involving shifts or rotations of ultrasound or computed tomography images. The consequences of several workflow procedures were tested with a phantom setup. As long as the reference ultrasound and computed tomography images are made to match, the patient will be in the correct treatment position. In an example with a phantom measurement, the accuracy of the performed manual fusion was found to be 2 mm. In clinical practice, manual registration of patient images is expected to be more difficult. Uncorrected mismatches will lead to a systematically incorrect final patient position because there will be no indication that there was a misregistration between the computed tomography and reference ultrasound images. In the treatment room, the fusion with the computed tomography image will not be visible and based on the ultrasound images the patient position seems correct.

show abstract

Quality assurance of U.S.‐guided external beam radiotherapy for prostate cancer: Report of AAPM Task Group 154

Cited by 41 publications

References 60 publications

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

Evaluation of uterine ultrasound imaging in cervical radiotherapy; a comparison of autoscan and conventional probe

Consequences of Intermodality Registration Errors for Intramodality 3D Ultrasound IGRT

Contact Info

Product

Resources

About