40. Validation of a transit EPID device for a clinical use: application to iViewDose (Elekta)

Delaby, N.; Bouvier, Jeanne; Jouyaux, F.; Barateau, A.; Lafond, C.

doi:10.1016/j.ejmp.2017.10.065

Cited by 4 publications

(4 citation statements)

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“…The 3D method verifies the whole patient volume, and the reconstructed dose on the CT scan is compared with the planned dose to judge dosimetric errors on their clinical relevance. A variety of VMAT verification methods have been described in the literature [3–6], some of which have been proven useful for QA; however, they have weaknesses. For instance, Electronic Portal Imaging Device (EPID) dosimetry has a limited field of view; film dosimetry offers high resolution but is labour intensive; and detector array also has a limited field of view and spatial resolution.…”

Section: Introductionmentioning

confidence: 99%

Pre-treatment 2D and 3D dosimetric verification of volumetric arc therapy. A correlation study between gamma index passing rate and clinical dose volume histogram

Szczurek¹,

Juszkat²,

Szczurek³

et al. 2019

PLoS ONE

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Objectives To evaluate methods for the pre-treatment verification of volumetric modulated arc therapy (VMAT) based on the percentage gamma passing rate (%GP) and its correlation and sensitivity with percentage dosimetric errors (%DE). Methods A total of 25 patients with prostate cancer and 15 with endometrial cancer were analysed. The %GP values of 2D and 3D verifications with different acceptance criteria (1%/1 mm, 2%/2 mm, and 3%/3 mm) were obtained using OmniPro and Compass. The %DE was calculated using a planned dose volume histogram (DVH) created in Monaco’s treatment planning system (TPS), which relates radiation dose to tissue and the patient’s predicted dose volume histogram in Compass. Statistical correlation between %GP and %DE was verified using Pearson’s correlation coefficient. Sensitivity was calculated based on the receiver operating characteristics (ROC) curve. Plans were calculated using Collapsed Cone Convolution and the Monte Carlo algorithm. Results The t -test results of the planned and estimated DVH showed that the mean values were comparable ( P > 0.05). For the 3%/3 mm criterion, the average %GP was acceptable for the prostate and endometrial cancer groups, with average rates of 99.68 ± 0.49% and 99.03 ± 0.59% for 2D and 99.86 ± 0.39% and 99.53 ± 0.44% for 3D, respectively. The number of correlations was poor for all analysed data. The mean Pearson’s R-values for prostate and endometrial cancer were < 0.45 and < 0.43, respectively. The area under the ROC curve for the prostate and endometrial cancer groups, was lower than 0.667. Conclusions Analysis of the %GP versus %DE values revealed only weak correlations between 2D and 3D verifications. DVH results obtained using the Compass system will be helpful in confirming that the analysed plans respect dosimetric constraints.

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Section: Introductionmentioning

confidence: 99%

Pre-treatment 2D and 3D dosimetric verification of volumetric arc therapy. A correlation study between gamma index passing rate and clinical dose volume histogram

Szczurek¹,

Juszkat²,

Szczurek³

et al. 2019

PLoS ONE

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“…Within the subcategory of in vivo EPID dosimetry several implementations have been developed each of which verifies the dose to the patient in different ways. Several in-vivo EPID software solutions have been commercially available recently and have been assessed in a number of studies [12,13]. However, the solutions thus far have mainly been developed in house by academic centres, resulting in a wide variety of methodologies.…”

Section: Introductionmentioning

confidence: 99%

In-vivo EPID dosimetry for IMRT and VMAT based on through-air predicted portal dose algorithm

Najem

Tedder

et al. 2018

Physica Medica

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We have adapted the methodology of Berry et al. (2012) for Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) treatments at a fixed source to imager distance (SID) based on the manufacturer's through-air portal dose image prediction algorithm. In order to fix the SID a correction factor was introduced to account for the change in air gap between patient and imager. Commissioning data, collected with multiple field sizes, solid water thicknesses and air gaps, were acquired at 150 cm SID on the Varian aS1200 EPID. The method was verified using six IMRT and seven VMAT plans on up to three different phantoms. The method's sensitivity and accuracy were investigated by introducing errors. A global 3%/3 mm gamma was used to assess the differences between the predicted and measured portal dose images. The effect of a varying air gap on EPID signal was found to be significant - varying by up to 30% with field size, phantom thickness, and air gap. All IMRT plans passed the 3%/3 mm gamma criteria by more than 95% on the three phantoms. 23 of 24 arcs from the VMAT plans passed the 3%/3 mm gamma criteria by more than 95%. This method was found to be sensitive to a range of potential errors. The presented approach provides fast and accurate in-vivo EPID dosimetry for IMRT and VMAT treatments and can potentially replace many pre-treatment verifications.

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“…The ability to verify the fluency of dose in real time would allow the patient to start radiotherapy earlier as well as to check the dose distribution daily. [26][27][28][29].…”

Section: Dose Detectorsmentioning

confidence: 99%

“…In-vivo verification of dose distribution using iViewDose software Some studies presented slightly higher gamma values of the in-vivo data comparing to a pre-treatment verification measurement. However, this strong correlation has been achieved for IMRT treatment plans [27]. In the course of the dose calculation process, in the treatment planning system, it is still unknown how the dose will be deposited in the patient's body with every fraction.…”

Section: Different Dose Calculation Algorithmsmentioning

confidence: 99%

Comparison of pre-treatment and in-vivo dosimetry for advanced radiotherapy of prostate cancer

Bartnikowska

Cieślik²,

Młodzik³

et al. 2022

Rep Pract Oncol Radiother.

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40. Validation of a transit EPID device for a clinical use: application to iViewDose (Elekta)

Cited by 4 publications

References 0 publications

Pre-treatment 2D and 3D dosimetric verification of volumetric arc therapy. A correlation study between gamma index passing rate and clinical dose volume histogram

Pre-treatment 2D and 3D dosimetric verification of volumetric arc therapy. A correlation study between gamma index passing rate and clinical dose volume histogram

In-vivo EPID dosimetry for IMRT and VMAT based on through-air predicted portal dose algorithm

Comparison of pre-treatment and in-vivo dosimetry for advanced radiotherapy of prostate cancer

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