Dose verification of volumetric modulation arc therapy by using a NIPAM gel dosimeter combined with a parallel-beam optical computed tomography scanner

Yao, Chun‐Hsu; Chang, Tse Wen; Tsai, Min-Jia; Lai, Yen‐Chung; Chen, Yi‐An; Chang, Yuan‐Jen; Chen, Chin-Hsing

doi:10.1007/s10967-016-5161-2

Cited by 14 publications

(6 citation statements)

References 22 publications

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“…The conclusion drawn from that study was that plan complexity affected the VMAT plan pass rate . As control, 3%/3 mm of the gamma pass rate of simple lung cancer patients and complex laryngeal cancer patients was 99.19 (+ 0.122%) and 87.15 (+ 0.154%), respectively . In head and neck planning, attention should be paid to controlling the number of fields as much as possible under the precondition of meeting clinical organ tolerance and planning target volume prescription dose coverage.…”

Section: Discussionmentioning

confidence: 99%

Analysis of dose verification results for 924 intensity‐modulated radiation therapy plans

Chen

et al. 2018

Precision Radiation Oncology

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Objective Intensity‐modulated radiation therapy (IMRT) plays an increasingly important role in clinical applications, and dose verification is particularly crucial for each patient. In the present study, we retrospectively analyzed the results of dose verification in 924 actual IMRT plans, including the relationship between gamma pass rates and the location of lesions, and the total number of monitor units, and the maximum area of the collected dose. Methods All the 924 IMRT plans implemented in a Varian Trilogy accelerator between 1 January 2014 and 31 March 2016 at Shandong Cancer Hospital were acquired. The Varian Eclipse planning system was used for all treatment planning and verification. Then, actual implemented plans were transplanted into a water phantom. Subsequently, the derived fluence was compared with the actual measured fluence by gamma analysis with the gamma criteria (3%/3 mm). Results A total of 924 IMRT plans were categorized into six groups, including the brain, head and neck, chest, abdomen, pelvis, and breast. The gamma pass rate average was >98% for 902 IMRT plans, whereas 22 plans did not pass the first time. A correlation was observed between the treatment site and gamma pass rate (P = 0.017). Meanwhile, a negative correlation was observed between the gamma pass rate and the total number of monitor units (P < 0.001), and the largest area of the acquisition dose (P < 0.001), respectively. Varian Trilogy accelerator IMRT QA data has a stable pass rate with a 100 confidence limit (CL) value of 95.19. Conclusion There was a correlation between the pass rate and the treatment site, the total number of monitor units, and the maximum area of collected dose. When using Mapcheck for patient plan dose verification, the gamma pass rate is very high, and only a few of them need to be analyzed.

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Section: Discussionmentioning

confidence: 99%

Analysis of dose verification results for 924 intensity‐modulated radiation therapy plans

Chen

et al. 2018

Precision Radiation Oncology

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“…Previous studies have confirmed that the NIPAM 3D gel dosimeter with OCT could provide good dose verification for photon therapy [5][6][7][8] and developed various combinations to obtain the sensitivity linearity formulas most suitable for photon therapy. Different gel formulations could be used to achieve the precision of NIPAM polymer gels for various clinical applications [9][10][11].…”

Section: Introductionmentioning

confidence: 87%

Feasibility evaluation of N-Isopropyl Acrylamide 3D gel dosimeters for proton therapy

Yao,

Huang,

Juan

et al. 2023

PLoS ONE

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This study aimed to investigate the feasibility of applying 3D gel dosimeters for proton therapy. Two different formulations (5-5-3-5, 5-3-3-10) for the N-Isopropyl Acrylamide (NIPAM) polymer gel were used to find the best composition for the application of NIPAM polymer gels for proton therapy. The reaction of the gel under different physical conditions, including dependence on energy and dependence on the dose rate of the NIPAM gel under proton irradiation, was also explored. A NIPAM gel dosimeter was used to record the 3D dose distribution, and a self-developed parallel beam optical computed tomography scanner was used to obtain non-irradiated and post-irradiated gel phantom images. The NIPAM gel was filled into a cylindrical acrylic phantom. The results showed that the optical density of the irradiated NIPAM dosimeter was linear in the dose range of 0 to 6 Gy, and the linearity of the two NIPAM gel formulations at the depth of the dose point (2 cm) was 0.98 to 0.89. The dose depth curves showed different patterns with different gel sensitivities. This study demonstrated that the NIPAM gel dosimeter with the 5-3-3-10 formulation is suitable for verifying the dosimetry dose of proton beams.

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“…Various studies have analyzed the MRI response of polymer gels for possible application in radiotherapy dose mapping ([ 58 , 63 ] and references therein). In particular, polymer gels have been investigated for dosimetry in conformal therapy, IMRT, IMAT, IGRT, VMAT and tomotherapy [ 55 , 70 , 83 , 88 , 102 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 ], small photon fields [ 136 , 137 , 138 ], stereotactic radiosurgery [ 55 , 139 , 140 , 141 , 142 ], 60-cobalt source [ 143 , 144 ], brachytherapy [ 55 , 85 , 92 , 145 , ...…”

Section: Polyacrylamide Gelsmentioning

confidence: 99%

Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry

Marrale

D’Errico

2021

Gels

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Radiation-sensitive gels are among the most recent and promising developments for radiation therapy (RT) dosimetry. RT dosimetry has the twofold goal of ensuring the quality of the treatment and the radiation protection of the patient. Benchmark dosimetry for acceptance testing and commissioning of RT systems is still based on ionization chambers. However, even the smallest chambers cannot resolve the steep dose gradients of up to 30–50% per mm generated with the most advanced techniques. While a multitude of systems based, e.g., on luminescence, silicon diodes and radiochromic materials have been developed, they do not allow the truly continuous 3D dose measurements offered by radiation-sensitive gels. The gels are tissue equivalent, so they also serve as phantoms, and their response is largely independent of radiation quality and dose rate. Some of them are infused with ferrous sulfate and rely on the radiation-induced oxidation of ferrous ions to ferric ions (Fricke-gels). Other formulations consist of monomers dispersed in a gelatinous medium (Polyacrylamide gels) and rely on radiation-induced polymerization, which creates a stable polymer structure. In both gel types, irradiation causes changes in proton relaxation rates that are proportional to locally absorbed dose and can be imaged using magnetic resonance imaging (MRI). Changes in color and/or opacification of the gels also occur upon irradiation, allowing the use of optical tomography techniques. In this work, we review both Fricke and polyacrylamide gels with emphasis on their chemical and physical properties and on their applications for radiation dosimetry.

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Dose verification of volumetric modulation arc therapy by using a NIPAM gel dosimeter combined with a parallel-beam optical computed tomography scanner

Cited by 14 publications

References 22 publications

Analysis of dose verification results for 924 intensity‐modulated radiation therapy plans

Analysis of dose verification results for 924 intensity‐modulated radiation therapy plans

Feasibility evaluation of N-Isopropyl Acrylamide 3D gel dosimeters for proton therapy

Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry

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