Cone Beam CT-Based Three-Dimensional Planning in High-Dose-Rate Brachytherapy for Cervical Cancer

Al-Halabi, H.; Portelance, Lorraine; Duclos, Marie; Reniers, Brigitte; Bahoric, Boris; Souhami, Luís

doi:10.1016/j.ijrobp.2009.06.036

Cited by 15 publications

(12 citation statements)

References 34 publications

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“…In brachytherapy, the use of a CBCT scanner in the treatment room has been investigated to a limited extent, e.g., to investigate the possible use a CBCT scanner for conventional TG-43 dose to water calculations in HDR cervix treatment. 141,142 Dose to medium calculations in brachytherapy based on kV-CBCT imaging has not been attempted yet. HU calibration in kV-CBCT seems an issue that deserves more attention and CBCT images should not be used for brachytherapy dose calculations when tissue heterogeneity information needs to be taken into account.…”

Section: Iva3 Cbct Segmentationmentioning

confidence: 99%

Report of the Task Group 186 on model‐based dose calculation methods in brachytherapy beyond the TG‐43 formalism: Current status and recommendations for clinical implementation

et al. 2012

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The charge of Task Group 186 (TG-186) is to provide guidance for early adopters of model-based dose calculation algorithms (MBDCAs) for brachytherapy (BT) dose calculations to ensure practice uniformity. Contrary to external beam radiotherapy, heterogeneity correction algorithms have only recently been made available to the BT community. Yet, BT dose calculation accuracy is highly dependent on scatter conditions and photoelectric effect cross-sections relative to water. In specific situations, differences between the current water-based BT dose calculation formalism (TG-43) and MBDCAs can lead to differences in calculated doses exceeding a factor of 10. MBDCAs raise three major issues that are not addressed by current guidance documents: (1) MBDCA calculated doses are sensitive to the dose specification medium, resulting in energy-dependent differences between dose calculated to water in a homogeneous water geometry (TG-43), dose calculated to the local medium in the heterogeneous medium, and the intermediate scenario of dose calculated to a small volume of water in the heterogeneous medium. (2) MBDCA doses are sensitive to voxel-by-voxel interaction cross sections. Neither conventional single-energy CT nor ICRU∕ICRP tissue composition compilations provide useful guidance for the task of assigning interaction cross sections to each voxel. (3) Since each patient-source-applicator combination is unique, having reference data for each possible combination to benchmark MBDCAs is an impractical strategy. Hence, a new commissioning process is required. TG-186 addresses in detail the above issues through the literature review and provides explicit recommendations based on the current state of knowledge. TG-43-based dose prescription and dose calculation remain in effect, with MBDCA dose reporting performed in parallel when available. In using MBDCAs, it is recommended that the radiation transport should be performed in the heterogeneous medium and, at minimum, the dose to the local medium be reported along with the TG-43 calculated doses. Assignments of voxel-by-voxel cross sections represent a particular challenge. Electron density information is readily extracted from CT imaging, but cannot be used to distinguish between different materials having the same density. Therefore, a recommendation is made to use a number of standardized materials to maintain uniformity across institutions. Sensitivity analysis shows that this recommendation offers increased accuracy over TG-43. MBDCA commissioning will share commonalities with current TG-43-based systems, but in addition there will be algorithm-specific tasks. Two levels of commissioning are recommended: reproducing TG-43 dose parameters and testing the advanced capabilities of MBDCAs. For validation of heterogeneity and scatter conditions, MBDCAs should mimic the 3D dose distributions from reference virtual geometries. Potential changes in BT dose prescriptions and MBDCA limitations are discussed. When data required for full MBDCA implementation are insufficient, interim ...

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Section: Iva3 Cbct Segmentationmentioning

confidence: 99%

Report of the Task Group 186 on model‐based dose calculation methods in brachytherapy beyond the TG‐43 formalism: Current status and recommendations for clinical implementation

et al. 2012

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“…However, the majority prescribes to Point A rather than using 3D image based dosimetry (Viswanathan & Erickson, 2010). Another authors concluded that calculating dose-volume histograms (DVHs) using 3D-based volumetric planning may provide a more accurate evaluation of the dose to the target volume and OARs (Al-Halabi et al, 2010). In addition, better imaging of the target and OARs allows for a more precise delineation of the target volume and OARs and, consequently, a better assessment of the dose delivered to these structures (Nag et al, 2004).…”

Section: Gynecological Tumorsmentioning

confidence: 99%

CT-Image Guided Brachytherapy

Skowronek¹

2011

Theory and Applications of CT Imaging and Analysis

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“…Cone‐beam CT (CBCT) scanners are becoming more available in surgical theatres and are commonly used in image guidance in radiotherapy, angiography, mammography and orthopaedics . Previous studies have investigated CBCT in the context of brachytherapy. Al‐Halabi et al .…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies have investigated CBCT in the context of brachytherapy. Al‐Halabi et al . utilised CBCT for intracavitary HDR brachytherapy treatment planning for cervical cancer and were able to sufficiently delineate the CTV and OARs (bladder and rectum).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a mobile C‐arm cone‐beam CT in interstitial high‐dose‐rate prostate brachytherapy treatment planning

Djukelic

Waterhouse

Toh

et al. 2019

J of Medical Radiation Sci

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Introduction The aim of this study was to evaluate the suitability of using cone‐beam computed tomography (CBCT) obtained with a mobile C‐arm X‐ray fluoroscopy unit as a single modality for planning of high‐dose‐rate (HDR) prostate brachytherapy treatments. Methods The feasibility of using CBCT images obtained using a Siemens Arcadis Orbic 3D mobile C‐arm was evaluated. A retrospective clinical study was undertaken of six participants undergoing HDR prostate brachytherapy. Plans generated using images from a Toshiba Aquilion One LB CT were compared with those generated using CBCT images. After rigid spatial registration, the plans were compared based on various parameters such as dose‐volume histograms, overlap quantities and metrics, and dose constraints. Results Provided they were within the limited field of view, the brachytherapy catheters and fiducial markers were clearly visible in the CBCT images and thus, localisable and identifiable in the treatment planning process. The Siemens CBCT underestimated CT numbers leading to poorer tissue contrast which exacerbated the difficulties in delineation of the target tumour and the surrounding organs at risk. Between CT‐ and CBCT‐based plans, the mean difference of CTV‐D90 was 1.58 Gy, CTV‐V100 was 12.13%, rectum‐V80 was 0.06% and urethra‐V120 was −0.70%. Conclusion It was not feasible to solely utilise the Siemens Arcadis Orbic 3D for HDR prostate brachytherapy treatment planning due to suboptimal organ delineation. However, the methods in this study could be used to evaluate other mobile CBCT imaging devices for feasibility in HDR brachytherapy treatment planning since the results indicated that it may not be necessary to have standard quality CT images for treatment planning.

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Cone Beam CT-Based Three-Dimensional Planning in High-Dose-Rate Brachytherapy for Cervical Cancer

Cited by 15 publications

References 34 publications

Report of the Task Group 186 on model‐based dose calculation methods in brachytherapy beyond the TG‐43 formalism: Current status and recommendations for clinical implementation

Report of the Task Group 186 on model‐based dose calculation methods in brachytherapy beyond the TG‐43 formalism: Current status and recommendations for clinical implementation

CT-Image Guided Brachytherapy

Evaluation of a mobile C‐arm cone‐beam CT in interstitial high‐dose‐rate prostate brachytherapy treatment planning

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