Dose verification of a clinical intensity-modulated radiation therapy eye case by the magnetic resonance imaging of N-isopropylacrylamide gel dosimeters

Chen, Yen-Li; Hsieh, Bor‐Tsung; Chiang, Chih-Ming; Shih, Chuen-Ming; Cheng, Kai Yuan; Hsieh, Ling‐Ling

doi:10.1016/j.radphyschem.2013.12.037

Cited by 10 publications

(2 citation statements)

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“…The dosimetric system ITA-BIS presented a sigmoidal behavior like other polymeric dosimeters, however the initial dose neccesary to obtain a clear distinguishale and reliable response by optical methods was relatively high compared with other polymeric dosimeters(Basfar et al, 2015;Chen et al, 2014). The effect of changes in the total reactive material concentration can be observed inFigure 5 and Figure 6.…”

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confidence: 85%

Polymer gel dosimeter based on itaconic acid

Mattea

Chacón

Vedelago

et al. 2015

Applied Radiation and Isotopes

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A new polymeric dosimeter based on itaconic acid and N, N'-methylenebisacrylamide was studied. The preparation method, compositions of monomer and crosslinking agent and the presence of oxygen in the dosimetric system were analyzed. The resulting materials were irradiated with an X-ray tube at 158cGy/min, 226cGymin and 298cGy/min with doses up to 1000Gy. The dosimeters presented a linear response in the dose range 75-1000Gy, sensitivities of 0.037 1/Gyat 298cGy/min and an increase in the sensitivity with lower dose rates. One of the most relevant outcomes in this study was obtaining different monomer to crosslinker inclusion in the formed gel for the dosimeters where oxygen was purged during the preparation method. This effect has not been reported in other typical dosimeters and could be attributed to the large differences in the reactivity among these species.

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mentioning

confidence: 85%

Polymer gel dosimeter based on itaconic acid

Mattea

Chacón

Vedelago

et al. 2015

Applied Radiation and Isotopes

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“…Gel dosimeters are generally considered stabilized and readable at 24 h postirradiation [ 11 , 13 ]. In subsequent investigations, simple dose distributions and γ-index maps from gel measurements have been compared with those from treatment planning system (TPS) calculations regarding central axial planar dose distributions [ 14 ].…”

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confidence: 99%

A Comprehensive Evaluation of NIPAM Polymer Gel Dosimeters on Three Orthogonal Planes and Temporal Stability Analysis

2016

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Polymer gel dosimeters have been proven useful for dose evaluation in radiotherapy treatments. Previous studies have demonstrated that using a polymer gel dosimeter requires a 24 h reaction time to stabilize and further evaluate the measured dose distribution in two-dimensional dosimetry. In this study, the short-term stability within 24 h and feasibility of N-isopropylacrylamide (NIPAM) polymer gel dosimeters for use in three-dimensional dosimetry were evaluated using magnetic resonance imaging (MRI). NIPAM gels were used to measure the dose volume in a clinical case of intensity-modulated radiation therapy (IMRT). For dose readouts, MR images of irradiated NIPAM gel phantoms were acquired at 2, 5, 12, and 24 h after dose delivery. The mean standard errors of dose conversion from using dose calibration curves (DRC) were calculated. The measured dose volumes at the four time points were compared with those calculated using a treatment planning system (TPS). The mean standard errors of the dose conversion from using the DRCs were lower than 1 Gy. Mean pass rates of 2, 5, 12, and 24 h axial dose maps calculated using gamma evaluation with 3% dose difference and 3 mm distance-to-agreement criteria were 83.5% ± 0.9%, 85.9% ± 0.6%, 98.7% ± 0.3%, and 98.5% ± 0.9%, respectively. Compared with the dose volume histogram of the TPS, the absolute mean relative volume differences of the 2, 5, 12, and 24 h measured dose volumes were lower than 1% for the irradiated region with an absorbed dose higher than 2.8 Gy. It was concluded that a 12 h reaction time was sufficient to acquire accurate dose volume using the NIPAM gels with MR readouts.

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