Clinical applications of 3-D dosimeters

Wuu, Cheng-Shie

doi:10.1088/1742-6596/573/1/012011

Cited by 3 publications

(5 citation statements)

References 32 publications

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“…Figure 7 plots the dose response curve of PRESAGE sheets irradiated to an absorbed dose range of 0-20 Gy at measured time points of 1, 10, 20, 72, and 168 h postirradiation. It was observed that the slope of the dose response curve or dose response sensitivity 20,21 (ΔOD/Gy) of PRESAGE sheets stored in a refrigerated or freezer environment changes at a slower rate over time than those stored in a room temperature environment postirradiation, as documented in Table I, due to the reduced rate of signal decay observed in Fig. 6.…”

Section: D Vmat Measurements and Analysismentioning

confidence: 91%

“…Figure 6 shows the temporal dependence of the measured signal in PRESAGE sheets irradiated to an absorbed dose of 3-20 Gy when stored under different temperature conditions: freezer (-18°C), fridge (4°C), and room temperature (22°C ). From these data points it was observed that the signal decay rate (ΔOD/hr) and temporal change in the dose response sensitivity 20,21 (ΔOD/Gy) of irradiated PRESAGE-LCV sheets were diminished for sheets stored in colder temperature environments postirradiation. When measured 20 h after irradiation, the entire dataset of PRESAGE-LCV sheets stored in a refrigerated environment had measured ΔOD values that were within 90.2 AE 3.4% of the measured ΔOD values scanned at an initial elapsed postirradiation time of 1 h. PRESAGE-LCV sheets stored in a room temperature environment, however, had scanned ΔOD values from the entire dataset that were within 71.5 AE 5.3% of the measured ΔOD values obtained at an elapsed postirradiation time of 1 h. To further cement the hypothesis that storage in a cooler environment stabilizes the measured signal in PRESAGE-LCV sheets, the scanned ΔOD for the entire dataset of sheets placed in a freezing environment at an elapsed postirradiation time of 20 h was measured to be within 95.3 AE 0.9% of the ΔOD values scanned at an elapsed time of 1 h postirradiation.…”

Section: D Vmat Measurements and Analysismentioning

confidence: 99%

“…Treatment plan evaluation of IMRT and VMAT based on three-dimensional (3D) dosimetric information can be meaningfully evaluated through the use of a volumetric dosimeter that accurately measures complex 3D dose distributions with high spatial resolution. 1,2 In recent years, a novel plastic radiochromic dosimeter known as PRESAGE had been developed for 3D dosimetry. 3,4 It is comprised of a halocarbon free radical initiator and leuco dye variant dissolved in a transparent polyurethane substrate.…”

Section: Introductionmentioning

confidence: 99%

“…Modern treatment delivery techniques such as intensity‐modulated radiation therapy (IMRT) and volumetric‐modulated arc therapy (VMAT) are able to optimize the dose distribution by delivering a high radiation dose to the tumor while sparing the surrounding normal tissue through modulation of the beam intensity profiles to meet the goals of a composite treatment plan. Treatment plan evaluation of IMRT and VMAT based on three‐dimensional (3D) dosimetric information can be meaningfully evaluated through the use of a volumetric dosimeter that accurately measures complex 3D dose distributions with high spatial resolution 1,2 . In recent years, a novel plastic radiochromic dosimeter known as PRESAGE had been developed for 3D dosimetry 3,4 .…”

Section: Introductionmentioning

confidence: 99%

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Temperature dependence and temporal stability of stacked radiochromic sheets for three‐dimensional dose verification

et al. 2020

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Purpose Recently a novel radiochromic sheet dosimeter, termed as PRESAGE sheets, consisting of leuco crystal violet dye and radical initiator had been developed and characterized. This study examines the dosimeter’s temporal stability and storage temperature dependence postirradiation, and its applicability for dose verification in three dimensions (3D) as a stack dosimeter. Methods PRESAGE sheets were irradiated using 6 MV photons at a dose range of 0–20 Gy with the change in optical density measured using a flatbed scanner. Following their irradiation, PRESAGE sheets were stored in different temperature environments (–18 °C, 4 °C, and 22 °C) and scanned at different time points, ranging from 1 to 168 h postirradiation, to track changes in measured signal and linearity of dose response. Multiple PRESAGE sheets were bound together to create a 12 × 13 × 8.7 cm3 film stack, with EBT3 film inserted between the sheets in the central region of the stack, that was treated using a clinical VMAT plan. Based on the results from the time and storage temperature study, two‐dimensional (2D) relative dose distribution measurements in PRESAGE were acquired promptly following irradiation at selected planes in the coronal, sagittal, and axial orientation of the film stack and compared to the treatment planning system calculations in their respective axes. Dose distribution measurements on the coronal axis of the stack dosimeter were also independently verified using EBT3 film. Results The dose response was observed to be linear (R2> 0.995) with sheets stored in colder temperatures retaining their signal and dose response sensitivity for extended periods postirradiation. Sheets stored in 22 °C environment should be measured within an hour postirradiation. Sheets stored in a 4 °C and −18 °C environment can be scanned up to 20‐ and 72 h postirradiation, respectively, while preserving the integrity of their dose response sensitivity and linearity of dose response within a mean absolute percent error of 2.0%. For instance, at 20 h postirradiation the dose response sensitivity for sheets stored in a −18 °C, 4 °C, and 22 °C temperature environment was measured to be 97%, 91%, and 77% of their original values measured within an hour postirradiation, respectively. The 2D gamma pass rate for central slices exceed 95% for PRESAGE film stack compared with treatment planning system on selected planes in the axial, coronal, and sagittal orientation and EBT3 film in the coronal orientation using a 2D gamma index of 2%/2mm. The gamma pass rate in comparing the calculated dose distribution with the measured dose distribution from PRESAGE‐LCV was observed to decrease in sheets scanned at later elapsed times postirradiation. In one example, the gamma pass rate for 2%/2mm criteria in the coronal plane was observed to decrease from 97.7% pass rate when scanned within an hour postirradiation to 92.1% pass rate when scanned at 20 h postirradiation under room temperature conditions. Conclusions This is the first study to demonstrate that the temporal s...

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Section: D Vmat Measurements and Analysismentioning

confidence: 91%

Section: D Vmat Measurements and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Temperature dependence and temporal stability of stacked radiochromic sheets for three‐dimensional dose verification

et al. 2020

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“…PRESAGE â dosimeters with identical chemical make-up have been found to differ in sensitivity and spatial uniformity. 21 Therefore, further studies are necessary to evaluate the robustness of a remote dosimetry correction protocol. Considering the interbatch sensitivity variation of PRESAGE â , one approach may require tuning the corrections on a per-batch basis, similar to dose-calibration with 2D radiochromic film when implementing spatial uniformity corrections.…”

Section: C Modeling and Interpretation Of Remote Dosimetry Correctmentioning

confidence: 99%