Equivalent doses for gynecological patients undergoing IMRT or RapidArc with kilovoltage cone beam CT

Qiu, Yue; Moiseenko, Vitali; Aquino‐Parsons, Christina; Duzenli, Cheryl

doi:10.1016/j.radonc.2012.07.007

Cited by 18 publications

(13 citation statements)

References 33 publications

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“…Our scatter doses to the breast from both VMAT and IMRT are similar to those reported by Qiu et al [28], but our leakage doses are larger. The difference possibly results from the use of different study methods and prescribed doses.…”

Section: Discussionsupporting

confidence: 90%

“…A little data have been reported on the peripheral doses resulting from VMAT in cervical cancer radiotherapy. Qiu Y et al described the peripheral doses for gynecological patients undergoing IMRT or RapidArc (Varian Medical Systems, Palo Alto, CA) with kilovoltage cone beam CT [28]. This study shows that the IMRT leakage dose is approximately 6 cGy, uniformly distributed throughout the patient’s body, while the leakage dose from RapidArc is about 3 cGy, using a prescribed dose of 45 Gy.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Peripheral dose measurements in cervical cancer radiotherapy: a comparison of volumetric modulated arc therapy and step-and-shoot IMRT techniques

et al. 2014

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PurposeThe aim of this study was to investigate the peripheral doses resulting from volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) techniques in cervical cancer radiotherapy.MethodsNine patients with cervical cancer had treatment planned with both VMAT and IMRT. A specially designed phantom was used for this study, with ion chambers placed at interest points approximating the position of the breast, thyroid, and lens. The peripheral doses at the phantom interest points were measured and compared between the VMAT and IMRT techniques.ResultsVMAT provides a potential dosimetric advantage compared with IMRT. The mean (± standard deviation) peripheral dose to the breast point for 1 fraction (2 Gy) during VMAT measured 5.13 ± 0.96 mGy, compared with 9.04 ± 1.50 mGy for IMRT. At the thyroid and lens interest points, the mean (± standard deviation) peripheral dose during VMAT was 2.19 ± 0.33 and 2.16 ± 0.28 mGy, compared with 7.07 ± 0.76 and 6.97 ± 0.91 mGy for IMRT, respectively. VMAT reduced the monitor units used by 28% and shortened the treatment delivery time by 54% compared with IMRT.ConclusionWhile the dosimetric results are similar for both techniques, VMAT results in a lower peripheral dose to the patient and reduces the monitor-unit usage and treatment delivery time compared with IMRT.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Peripheral dose measurements in cervical cancer radiotherapy: a comparison of volumetric modulated arc therapy and step-and-shoot IMRT techniques

et al. 2014

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“…They concluded that peripheral doses from imaging, at measurement points of equal distance from the central axis, are of the same order of magnitude as those of an IMRT treatment. Qiu et al [67] also investigated the magnitude of peripheral dose from kV CBCT as well as IMRT delivery and linac head leakage using MC simulation and concluded that dose to peripheral organs from CBCT is of the same order of magnitude as linac leakage and one order of magnitude lower than IMRT or RapidArc scatter dose.…”

Section: Peripheral Dose From Cbct Imagingmentioning

confidence: 99%

Imaging dose from cone beam computed tomography in radiation therapy

2015

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Imaging dose in radiation therapy has traditionally been ignored due to its low magnitude and frequency in comparison to therapeutic dose used to treat patients. The advent of modern, volumetric, imaging modalities, often as an integral part of linear accelerators, has facilitated the implementation of image-guided radiation therapy (IGRT), which is often accomplished by daily imaging of patients. Daily imaging results in additional dose delivered to patient that warrants new attention be given to imaging dose. This review summarizes the imaging dose delivered to patients as the result of cone beam computed tomography (CBCT) imaging performed in radiation therapy using current methods and equipment. This review also summarizes methods to calculate the imaging dose, including the use of Monte Carlo (MC) and treatment planning systems (TPS). Peripheral dose from CBCT imaging, dose reduction methods, the use of effective dose in describing imaging dose, and the measurement of CT dose index (CTDI) in CBCT systems are also reviewed.

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“…The MC method is regarded as the most accurate approach to model ionizing radiation transport for radiotherapy and imaging applications (Verhaegen and Seuntjens, 2003;Spezi and Lewis, 2008), and it is an ideal tool for CBCT patient dosimetry. The calculation of concomitant dose from both kV-and MV-CBCT units has been carried out extensively with the EGSnrc code system (which includes the BEAMnrc and DOSXYZnrc codes) and, to a lesser extent, with other MC codes such as MCNP and Geant4 (Chow et al, 2008;Ding et al, 2008a;Gu et al, 2008;Coffey, 2009, 2010;Downes et al, 2009;Spezi et al, 2009Spezi et al, , 2011Spezi et al, , 2012Walters et al, 2009;Qiu et al, 2011Qiu et al, , 2012Deng et al, 2012a,b;Zhang et al, 2012;Ding and Munro, 2013;Son et al, 2014). As reported by Alaei and Spezi (2015), several groups developed MC models for CBCT imaging systems and calculated 3D dose distributions using patient-specific CT scans or virtual phantoms.…”

Section: Dose Calculation Using MC Methodsmentioning

confidence: 99%

“…Once the computational model is commissioned, 3D dose calculation can be carried out by sampling the photons incident on the patient with one of the following methods using: (1) full MC simulation of the beam line (Qiu et al, 2011(Qiu et al, , 2012; (2) a phase space file representing the invariant parts of the unit or fixed field sizes (Chow et al, 2008;Ding et al, 2008a;Coffey, 2009, 2010;Downes et al, 2009;Walters et al, 2009;Spezi et al, 2012); (3) a source model representing the main sources of radiation (Spezi et al, 2011;Deng et al, 2012a,b;Zhang et al, 2012;Ding and Munro, 2013;Montanari et al, 2014); and (4) an x-ray spectrum (Gu et al, 2008;. Several groups (Chow et al, 2008;Downes et al, 2009;Spezi et al, 2009Spezi et al, , 2011Spezi et al, , 2012 have developed a computational model for the Elekta XVI CBCT unit using the EGSnrc/BEAMnrc code system and Beampp (a C++ implementation of the BEAMnrc MC code).…”

Section: Dose Calculation Using MC Methodsmentioning

confidence: 99%

Imaging Dose in Radiation Therapy

Sykes¹,

Alaei²,

Spezi³

2017

Clinical 3D Dosimetry in Modern Radiation Therapy

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Previous chapters in this book have concentrated on the instrumentation and measurement techniques for dosimetry of the therapeutic beams. In this chapter, a variety of measurement and calculation techniques will be reviewed for characterizing the radiation dose from x-ray imaging systems used in radiation therapy (RT). X-ray imaging systems are now used extensively throughout a patient's treatment for all complex RTs, and in many cases for simple palliative RTs as well. Nearly, all patients will undergo a multislice computed tomography (CT) examination for localizing the target volume and nearby organs at risk. In addition, a variety of x-ray imaging systems are available to image the patient at the point of treatment, either immediately prior to beam delivery (e.g., Korreman et al., 2010; Moore et al., 2014) to ensure accurate patient alignment, or during beam delivery to monitor intrafraction motion 22.1 Introduction 22.2 Dose Measurement for CT 22.3 Dose Measurement for CBCT for Radiotherapy Applications 22.4 Measurement (and Calculation) of Dose for Planar kV Imaging 22.5 Dose Measurement for MV Portal Imaging 22.6 Dose Measurement for MVCT and MV-CBCT 22.7 Dosimeters for All Modalities 22.8 Dose Calculation Methods 22.9 Estimating Effective Dose and Risk 22.10 Combining Dose from RT and Imaging 22.11 Clinical Consequences and Benefits 22.12 Closing Remarks 9781482252217_C022.indd 561 21/07/17 5:53 PM * MV-CBCT was developed and commercialized by Siemens Medical Systems, but is no longer commercially available since Siemens stopped producing radiation therapy treatment machines.

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Equivalent doses for gynecological patients undergoing IMRT or RapidArc with kilovoltage cone beam CT

Cited by 18 publications

References 33 publications

Peripheral dose measurements in cervical cancer radiotherapy: a comparison of volumetric modulated arc therapy and step-and-shoot IMRT techniques

Peripheral dose measurements in cervical cancer radiotherapy: a comparison of volumetric modulated arc therapy and step-and-shoot IMRT techniques

Imaging dose from cone beam computed tomography in radiation therapy

Imaging Dose in Radiation Therapy

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