ExacTrac X-ray 6 degree-of-freedom image-guidance for intracranial non-invasive stereotactic radiotherapy: Comparison with kilo-voltage cone-beam CT

Ma, Jinli; Chang, Zheng; Wang, Zhiheng; Wu, Q; Kirkpatrick, John P.; Yin, Fang‐Fang

doi:10.1016/j.radonc.2009.09.009

Cited by 81 publications

(77 citation statements)

References 22 publications

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“…Several groups have evaluated positioning accuracies of independent IGRT methodologies utilizing floor mounted stereotactic X‐ray localization and gantry‐mounted volumetric (CBCT) imaging. Ma et al (51) reported residual RMS errors from 0.17 to 0.30 mm (σ from 0.17 to 0.29 mm) for stereotactic X‐ray localization and 0.35 to 0.50 mm (σ from 0.33 to 0.48 mm) for CBCT localization. Kim et al (38) reported average errors from

- 0.2

- 0.8 mm

(σ from 0.2 to 0.4 mm) for stereotactic X‐ray localization and 0.0 to 0.6 mm (σ from 0.5 to 0.7 mm) for CBCT localization.…”

Section: Discussionmentioning

confidence: 99%

Commissioning and initial stereotactic ablative radiotherapy experience with Vero

Solberg

Medin

Ramirez

et al. 2014

J Applied Clin Med Phys

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The purpose of this study is to describe the comprehensive commissioning process and initial clinical performance of the Vero linear accelerator, a new radiotherapy device recently installed at UT Southwestern Medical Center specifically developed for delivery of image‐guided stereotactic ablative radiotherapy (SABR). The Vero system utilizes a ring gantry to integrate a beam delivery platform with image guidance systems. The ring is capable of rotating ± 60° about the vertical axis to facilitate noncoplanar beam arrangements ideal for SABR delivery. The beam delivery platform consists of a 6 MV C‐band linac with a 60 leaf MLC projecting a maximum field size of 15×15 cm2 at isocenter. The Vero planning and delivery systems support a range of treatment techniques, including fixed beam conformal, dynamic conformal arcs, fixed gantry IMRT in either SMLC (step‐and‐shoot) or DMLC (dynamic) delivery, and hybrid arcs, which combines dynamic conformal arcs and fixed beam IMRT delivery. The accelerator and treatment head are mounted on a gimbal mechanism that allows the linac and MLC to pivot in two dimensions for tumor tracking. Two orthogonal kV imaging subsystems built into the ring facilitate both stereoscopic and volumetric (CBCT) image guidance. The system is also equipped with an always‐active electronic portal imaging device (EPID). We present our commissioning process and initial clinical experience focusing on SABR applications with the Vero, including: (1) beam data acquisition; (2) dosimetric commissioning of the treatment planning system, including evaluation of a Monte Carlo algorithm in a specially‐designed anthropomorphic thorax phantom; (3) validation using the Radiological Physics Center thorax, head and neck (IMRT), and spine credentialing phantoms; (4) end‐to‐end evaluation of IGRT localization accuracy; (5) ongoing system performance, including isocenter stability; and (6) clinical SABR applications.PACS number: 87.53.Ly

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- 0.2

- 0.8 mm

(σ from 0.2 to 0.4 mm) for stereotactic X‐ray localization and 0.0 to 0.6 mm (σ from 0.5 to 0.7 mm) for CBCT localization.…”

Section: Discussionmentioning

confidence: 99%

Commissioning and initial stereotactic ablative radiotherapy experience with Vero

Solberg

Medin

Ramirez

et al. 2014

J Applied Clin Med Phys

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“…4 In December of 2009, the Novalis Tx system (BrainLAB, Varian, Palo Alto, CA, USA), a recently available dedicated platform for image-guided SRS and conventional radiotherapy, was installed in place of the m3 system. [5][6][7][8][9][10][11] This system is equipped with an integrated high-defi nition (HD) mMLC (HD120). [6][7][8][9][10] The m3 mMLC systems, also integrated in the Novalis predecessor system, have a 3 mm leaf width for the central 4.2 cm of the beam, whereas the HD120 mMLC has a 2.5 mm leaf width for the central 8 cm.…”

Section: Introductionmentioning

confidence: 99%

Dosimetric comparison of 2.5 mm vs. 3.0 mm leaf width micro-multileaf collimator-based treatment systems for intracranial stereotactic radiosurgery using dynamic conformal arcs: implications for treatment planning

et al. 2011

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“…Figure 1 shows the system evaluated in this study with the dual kV planar imaging system labeled in red with an A and B. The ExacTrac system comes equipped with two ceiling mounted

25.5 cm \times 25.5 cm

aSi flat panel detectors 8 , 14 and two corresponding kV X‐ray tubes that project medially, anteriorly, and inferiorly (15) at oblique angles (45° from the mid‐sagittal plane of the accelerator 8 , 14 ) from the standard treatment position. The ExacTrac system is different with respect to traditional X‐ray systems in that: a) it has a large source‐to‐isocenter and source‐to‐detector distance (2.34 and 3.62 m, respectively (8) ); b) the detectors and X‐ray tubes are both in a fixed position; and c) the X‐rays project in an oblique direction relative to the patient (16) .…”

Section: Methodsmentioning

confidence: 99%

Development of image quality assurance measures of the ExacTrac localization system using commercially available image evaluation software and hardware for image‐guided radiotherapy

Stanley

Papanikolaou

Gutiérrez

2014

J Applied Clin Med Phys

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Quality assurance (QA) of the image quality for image‐guided localization systems is crucial to ensure accurate visualization and localization of target volumes. In this study, a methodology was developed to assess and evaluate the constancy of the high‐contrast spatial resolution, dose, energy, contrast, and geometrical accuracy of the BrainLAB ExacTrac system. An in‐house fixation device was constructed to hold the QCkV‐1 phantom firmly and reproducibly against the face of the flat panel detectors. Two image sets per detector were acquired using ExacTrac preset console settings over a period of three months. The image sets were analyzed in PIPSpro and the following metrics were recorded: high‐contrast spatial resolution (f30,f40,f50 (lp/mm)), noise, and contrast‐to‐noise ratio. Geometrical image accuracy was evaluated by assessing the length between to predetermined points of the QCkV‐1 phantom. Dose and kVp were recorded using the Unfors RaySafe Xi R/F Detector. The kVp and dose were evaluated for the following: Cranial Standard (CS) (80 kV,80 mA,80 ms), Thorax Standard (TS) (120 kV,160 mA,160 ms), Abdomen Standard (AS) (120 kV,160 mA,130 ms), and Pelvis Standard (PS) (120 kV,160 mA,160 ms). With regard to high‐contrast spatial resolution, the mean values of the f30 (lp/mm), f40 (lp/mm) and f50 (lp/mm) for the left detector were 1.39±0.04,1.24±0.05, and 1.09±0.04, respectively, while for the right detector they were 1.38±0.04,1.22±0.05, and 1.09±0.05, respectively. Mean CNRs for the left and right detectors were 148±3 and 143±4, respectively. For geometrical accuracy, both detectors had a measured image length of the QCkV‐1 of 57.9±0.5.15emmm. The left detector showed dose measurements of 20.4±0.2μ.15emGy.15em(CS), 191.8±0.7.15emμGy.15em(TS), 154.2±0.7.15emμGy.15em(AS), and 192.2±0.6.15emμGy.15em(PS), while the right detector showed 20.3±0.3.15emμGy.15em(CS), 189.7±0.8.15emμGy.15em(TS), 151.0±0.7.15emμGy.15em(AS), and 189.7±0.8.15emμGy.15em(PS), respectively. For X‐ray energy, the left detector (right X‐ray tube) had mean kVp readings of 81.6±0.5.15em(CS), 122.5±0.5.15em(TS), 122.0±0.8.15em(AS), and 122.1±0.7.15em(PS), and the right detector (left X‐ray tube) had 81.6±0.5.15em(CS), 120.8±0.5.15em(TS), 120.9±0.6.15em(AS), and 121.3±0.7.15em(PS). Run charts were created so that each parameter could be tracked over time and the constancy of the system could be monitored. A methodology was developed to assess the basic image quality parameters recommended by TG‐142 for the ExacTrac system. The ExacTrac system shows a consistent dose, kVp, high‐contrast spatial resolution, CNR, and geometrical accuracy for each detector over the evaluated timeframe.PACS number: 87.10.‐e

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ExacTrac X-ray 6 degree-of-freedom image-guidance for intracranial non-invasive stereotactic radiotherapy: Comparison with kilo-voltage cone-beam CT

Cited by 81 publications

References 22 publications

Commissioning and initial stereotactic ablative radiotherapy experience with Vero

Commissioning and initial stereotactic ablative radiotherapy experience with Vero

Dosimetric comparison of 2.5 mm vs. 3.0 mm leaf width micro-multileaf collimator-based treatment systems for intracranial stereotactic radiosurgery using dynamic conformal arcs: implications for treatment planning

Development of image quality assurance measures of the ExacTrac localization system using commercially available image evaluation software and hardware for image‐guided radiotherapy

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