Patient-specific radiotherapy quality assurance for estimating actual treatment dose

Tanabe, Yoshinori; Ishida, Takayuki; Eto, Hidetoshi; Sera, Tatsuhiro; Emoto, Yukio; Shimokawa, Mototsugu

doi:10.1016/j.meddos.2020.08.003

Cited by 9 publications

(3 citation statements)

References 20 publications

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“…This plan orchestrates continuous adjustments to the spatial distribution of the multi-leaf collimator (MLC), dose rate, and gantry rotational speed, ensuring delivery of the optimized dose. To ensure such precision, the dose calculated by the TPS should be consistent with the dose applied to the patient [1][2][3][4]. To achieve this outcome, a dosimeter with high spatial resolution based on high sensitivity per unit volume is required [5].…”

Section: Introductionmentioning

confidence: 99%

Feasibility assessment of polycrystalline CsPbI₃ relative dosimeters in photon and electron beam radiotherapy

Yang,

Park,

Kim

2024

J. Inst.

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Volumetric modulated arc therapy represents the latest technology in radiotherapy. It involves continuous modification of the multi-leaf collimator spatial distribution, dose rate, and gantry rotational speed, necessitating a dosimeter with high spatial resolution and exceptional sensitivity per unit volume. In particular, cesium-based inorganic perovskites have been studied for various applications, spanning from photoconductor solar cells to radiation detectors. These perovskites are renowned for their outstanding attributes, including thermal stability, inorganic stability, and light absorption capacity. Despite such advantageous characteristics, CsPbI3 materials have only been investigated in radiodiagnostics, with limited exploration in radiotherapy. To address this gap, this study verified the viability of CsPbI3 materials, note for their outstanding radiation detection efficiency, as dosimeters capable of measuring the radiation detection performance for radiotherapy devices. The reproducibility, linearity, and percent depth dose (PDD) were evaluated under the application of photon and electron beams in linear accelerators. The reproducibility assessment revealed impressive results, with the relative standard deviation registering at 0.53%, 0.32%, and 0.38% under electron beam energies of 6, 9, and 12 MeV and 0.45%, and 0.89% under photon beam energies of 6 and 15 MV. Moreover, the linearity test revealed an R 2 value of 0.9999, indicating high linearity, at 6, 9, and 12 MeV and at 6 and 15 MV. The PDD graphs drawn for the CsPbI3 dosimeter fabricated in this study showed that the D max points were consistent. The novel CsPbI3 dosimeter demonstrated a level of detection performance that satisfied all criteria; reproducibility, linearity, and PDD. The results collectively indicated that the CsPbI3 dosimeter can be used for dosimeters in radiotherapy devices.

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Section: Introductionmentioning

confidence: 99%

Feasibility assessment of polycrystalline CsPbI₃ relative dosimeters in photon and electron beam radiotherapy

Yang,

Park,

Kim

2024

J. Inst.

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“…However, differences in tissue density throughout the body (e.g., lung and bone) make it difficult to predict dose distribution in clinical use accurately. Equipment and patient-specific QA are important for identifying discrepancies between calculated and delivered radiation doses and assessing algorithm-based management of heterogeneities and other factors ( Miften et al , 2018 ; Tanabe et al , 2020 ). Orthovoltage radiotherapy is delivered in high prescription doses, similar to linear accelerator radiotherapy ( Medina et al , 2008 ; Pampena et al , 2016 ), but manufacturers generally do not sell radiation treatment planning systems.…”

Section: Introductionmentioning

confidence: 99%

Improving animal-specific radiotherapy quality assurance for kilovoltage X-ray radiotherapy using a 3D printed dog skull water phantom

Tanabe¹,

Iseri²,

Onizuka³

et al. 2023

Open Vet J

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Background: Accurate dose assessment during animal radiotherapy is beneficial for veterinary medicine and medical education. Aim: To visualize the radiation treatment distribution of orthovoltage X-ray equipment in clinical practice using Monte Carlo simulations and created a dog skull water phantom for animal-specific radiotherapy. Methods: EGSnrc-based BEAMnrc and DOSXYZnrc codes were used to simulate orthovoltage dose distributions. At 10, 20, 30, 40, 50 and 80 mm in a water phantom, depth dose was measured with waterproof Farmer dosimetry chambers and the diagonal off-axis ratio was measured with Gafchromic EBT3 film to simulate orthovoltage dose distributions. Energy differences between orthovoltage and linear accelerated radiotherapy were assessed with a heterogeneous bone and tissue virtual phantom. The animal-specific phantom for radiotherapy quality assurance was created from CT scans of a dog and printed with a three-dimensional printer using polyamide 12 nylon, with insertion points for dosimetry chambers and Gafchromic EBT3 film. Results: Monte Carlo simulated and measured dose distributions differed by no more than 2.0% along the central axis up to a depth of 80 mm. The anode heel effect occurred in shallow areas. The orthovoltage radiotherapy percentage depth dose in bone was >40%. Build-up was >40%, with build-down after bone exit, whereas linear accelerator radiotherapy absorption changed little in the bone. A highly water-impermeable, animal-specific dog skull water phantom could be created to evaluate dose distribution. Conclusion: Animal-specific water phantoms and Monte Carlo simulated pre-treatment radiotherapy is useful quality assurance for orthovoltage radiotherapy and yields a visually familiar phantom that will be useful for veterinary medical education.

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“…Intensity-modulated radiotherapy (IMRT) generates steep dose gradients and can deliver precise dose distributions to the target organs, thereby preventing the administration of high doses in the neighboring organs at risk (OARs) ( Lawrence et al ., 2010 ). The steep dose gradient of IMRT may cause adverse effects due to the positional deviation of setup errors, and the positional deviations for target organs and OARs may lead to a difference between the planned and actual doses ( Deveau et al ., 2010 ; Tanabe et al ., 2021 ). The setup error is considered the planning target volume (PTV) margin of uncertainty, and the radiotherapy dose is safely delivered to the target organ within the PTV margin ( Noghreiyan et al ., 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of setup errors of immobilization device for radiation therapy in companion animals

Iseri¹,

Hira²,

Tanabe³

et al. 2022

Open Vet J

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Background: Intensity-modulated radiotherapy (IMRT), which allows generating steep dose gradients, is a beneficial treatment for companion animals with adjacent target and risk organs. IMRT is essential for high setup accuracy for avoiding overdose to risk organs, and optimal radiotherapy is important for evaluating the setup accuracy of companion animals. Aim: To use an immobilization device to evaluate setup errors in radiotherapy for companion animals Materials and methods: We calculated setup errors in radiotherapy for 386 animals (dogs and cats; 3261 registration images) that underwent radiotherapy between 2016 and 2022. The companion animals were immobilized with a customized bite block and vacuum lock device. A quantile–quantile plot with 95% confidence interval (CI) was used to evaluate the histogram of the setup errors, and the systematic and random setup errors were calculated for each region (brain, head and neck, chest and abdomen, pelvis, and spine). Results: The setup error in each direction presented an extremely narrow-interval histogram, with the following lower and upper 95% CIs: cranial–caudal (−0.08, −0.06 cm); left–right (−0.04, −0.02 cm); and dorsal–ventral (−0.13, −0.11 cm). The mean systematic setup error was 0.16 cm (range: 0.12–0.36 cm), and the random error was 0.15 cm (range: 0.08–0.34 cm). The pelvis showed the highest systematic and random setup errors (mean: 0.36 and 0.23 cm, respectively). Conclusion: The use of an immobilization device enables highly accurate radiotherapy for companion animals (95% CI < 0.15 cm).

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Patient-specific radiotherapy quality assurance for estimating actual treatment dose

Cited by 9 publications

References 20 publications

Feasibility assessment of polycrystalline CsPbI₃ relative dosimeters in photon and electron beam radiotherapy

Feasibility assessment of polycrystalline CsPbI₃ relative dosimeters in photon and electron beam radiotherapy

Improving animal-specific radiotherapy quality assurance for kilovoltage X-ray radiotherapy using a 3D printed dog skull water phantom

Evaluation of setup errors of immobilization device for radiation therapy in companion animals

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Patient-specific radiotherapy quality assurance for estimating actual treatment dose

Cited by 9 publications

References 20 publications

Feasibility assessment of polycrystalline CsPbI3 relative dosimeters in photon and electron beam radiotherapy

Feasibility assessment of polycrystalline CsPbI3 relative dosimeters in photon and electron beam radiotherapy

Improving animal-specific radiotherapy quality assurance for kilovoltage X-ray radiotherapy using a 3D printed dog skull water phantom

Evaluation of setup errors of immobilization device for radiation therapy in companion animals

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Feasibility assessment of polycrystalline CsPbI₃ relative dosimeters in photon and electron beam radiotherapy

Feasibility assessment of polycrystalline CsPbI₃ relative dosimeters in photon and electron beam radiotherapy