Cone-beam-CT guided radiation therapy: technical implementation

Létourneau, D.; Wong, John W.; Oldham, Mark; Gulam, M; Watt, Lindsay; Jaffray, David A.; Siewerdsen, Jeffrey H.; Martínez, Álvaro

doi:10.1016/j.radonc.2005.03.001

Cited by 221 publications

(163 citation statements)

References 40 publications

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“…They include mobile in‐room computed tomography (CT) scanners, (4) CT on rails, 5 , 6 B‐mode ultrasound systems, (6) tomotherapy, (6) and kilovoltage 7 , 8 and megavoltage 2 , 9 cone‐beam CT scanners (CBCT), widely in use currently.…”

Section: Introductionmentioning

confidence: 99%

Adaptive optimization by 6 DOF robotic couch in prostate volumetric IMRT treatment: rototranslational shift and dosimetric consequences

Chiesa

Placidi

Azario

et al. 2015

J Applied Clin Med Phys

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The purpose of this study was to investigate the magnitude and dosimetric relevance of translational and rotational shifts on IGRT prostate volumetric‐modulated arc therapy (VMAT) using Protura six degrees of freedom (DOF) Robotic Patient Positioning System. Patients with cT3aN0M0 prostate cancer, treated with VMAT simultaneous integrated boost (VMAT‐SIB), were enrolled. PTV2 was obtained adding 0.7 cm margin to seminal vesicles base (CTV2), while PTV1 adding to prostate (CTV1) 0.7 cm margin in all directions, except 1.2 cm, as caudal margin. A daily CBCT was acquired before dose delivery. The translational and rotational displacements were corrected through Protura Robotic Couch, collected and applied to the simulation CT to obtain a translated CT (tCT) and a rototranslated CT (rtCT) on which we recalculated the initial treatment plan (TP). We analyzed the correlation between dosimetric coverage, organs at risk (OAR) sparing, and translational or rotational displacements. The dosimetric impact of a rototranslational correction was calculated. From October 2012 to September 2013, a total of 263 CBCT scans from 12 patients were collected. Translational shifts were <5mm in 81% of patients and the rotational shifts were <2∘ in 93% of patient scans. The dosimetric analysis was performed on 172 CBCT scans and calculating 344 VMAT‐TP. Two significant linear correlations were observed between yaw and the V20 femoral heads and between pitch rotation and V50 rectum (p<0.001); rototranslational correction seems to impact more on PTV2 than on PTV1, especially when margins are reduced. Rotational errors are of dosimetric significance in sparing OAR and in target coverage. This is relevant for femoral heads and rectum because of major distance from isocenter, and for seminal vesicles because of irregular shape. No correlation was observed between translational and rotational errors. A study considering the intrafractional error and the deformable registration is ongoing.PACS number: 87.55.de

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Section: Introductionmentioning

confidence: 99%

Adaptive optimization by 6 DOF robotic couch in prostate volumetric IMRT treatment: rototranslational shift and dosimetric consequences

Chiesa

Placidi

Azario

et al. 2015

J Applied Clin Med Phys

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“…To address some of the training needs required of using kV-CBCT, making use of already existing resources in the radiotherapy department could be a viable approach. The movement toward CT simulation in modern radiotherapy departments necessitates the availability of learning resources for the radiation therapist to gain experience with analyzing anatomical and planning data found in CT slices because kV-CBCT and CT images are comparable [17]. Therefore the radiation therapist's skill sets acquired from CT simulator could potentially be transferred when he or she assesses the daily kV-CBCT.…”

Section: Discussionmentioning

confidence: 99%

Practical Considerations in Cone Beam and Ultrasound IGRT Systems in Prostate Localization: A Review of the Literature

Tran

2009

Journal of Medical Imaging and Radiation Sciences

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“…The image quality of CBCT is crucial for accurate localization in the patient 2. Several studies on image quality and absorbed dose of commercially available CBCT have been reported 3, 4, 5, 6, 7, 8. Most of the investigations were on single‐source CBCT (SCBCT) imaging.…”

Section: Introductionmentioning

confidence: 99%

Image quality and absorbed dose comparison of single‐ and dual‐source cone‐beam computed tomography

Miura

Ozawa

Okazue³

et al. 2018

J Applied Clin Med Phys

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PurposeDual‐source cone‐beam computed tomography (DCBCT) is currently available in the Vero4DRT image‐guided radiotherapy system. We evaluated the image quality and absorbed dose for DCBCT and compared the values with those for single‐source CBCT (SCBCT).MethodsImage uniformity, Hounsfield unit (HU) linearity, image contrast, and spatial resolution were evaluated using a Catphan phantom. The rotation angle for acquiring SCBCT and DCBCT images is 215° and 115°, respectively. The image uniformity was calculated using measurements obtained at the center and four peripheral positions. The HUs of seven materials inserted into the phantom were measured to evaluate HU linearity and image contrast. The Catphan phantom was scanned with a conventional CT scanner to measure the reference HU for each material. The spatial resolution was calculated using high‐resolution pattern modules. Image quality was analyzed using ImageJ software ver. 1.49. The absorbed dose was measured using a 0.6‐cm3 ionization chamber with a 16‐cm‐diameter cylindrical phantom, at the center and four peripheral positions of the phantom, and calculated using weighted cone‐beam CT dose index (CBCTDI w).ResultsCompared with that of SCBCT, the image uniformity of DCBCT was slightly reduced. A strong linear correlation existed between the measured HU for DCBCT and the reference HU, although the linear regression slope was different from that of the reference HU. DCBCT had poorer image contrast than did SCBCT, particularly with a high‐contrast material. There was no significant difference between the spatial resolutions of SCBCT and DCBCT. The absorbed dose for DCBCT was higher than that for SCBCT, because in DCBCT, the two x‐ray projections overlap between 45° and 70°.ConclusionsWe found that the image quality was poorer and the absorbed dose was higher for DCBCT than for SCBCT in the Vero4DRT.

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Cone-beam-CT guided radiation therapy: technical implementation

Cited by 221 publications

References 40 publications

Adaptive optimization by 6 DOF robotic couch in prostate volumetric IMRT treatment: rototranslational shift and dosimetric consequences

Adaptive optimization by 6 DOF robotic couch in prostate volumetric IMRT treatment: rototranslational shift and dosimetric consequences

Practical Considerations in Cone Beam and Ultrasound IGRT Systems in Prostate Localization: A Review of the Literature

Image quality and absorbed dose comparison of single‐ and dual‐source cone‐beam computed tomography

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