Three-Dimensional Dose Verification for Intensity-Modulated Radiation Therapy in the Radiological Physics Centre Head-and-Neck Phantom Using Optical Computed Tomography Scans of Ferrous Xylenol–Orange Gel Dosimeters

Babic, Steven; Battista, Jerry; Jordan, Kevin

doi:10.1016/j.ijrobp.2007.11.032

Cited by 70 publications

(44 citation statements)

References 18 publications

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“…A number of different radiochromic systems have been investigated, from a system based on the standard Fricke solution (Gore et al 1984a), to formulations with additional chelating agents such as xylenol-orange to reduce diffusion of Fe 3+ ions and improve sensitivity (Kelly et al 1998, Babic et al 2008). Radiochromic plastic systems are available commercially as Presage® (Heuris Inc., Skillman, NJ.)…”

Section: Radiochromic Dosimetersmentioning

confidence: 99%

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Atkins

Humphrey

Duck

et al. 2010

J. Phys.: Conf. Ser.

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This thesis describes investigations into the design and evaluation of novel ultrasonic methods for 3-dimensional ionising radiation dose verification. Pulse-echo ultrasound methods were investigated for the measurement and analysis of complex radiation therapy dose delivery. The physical properties of MAGIC (Methacrylic and Ascorbic acid in Gelatin Initiated byCopper) polymer gel dosimeters have been characterized. The variations of speed of sound, ultrasonic attenuation coefficient and density of MAGIC gel with radiation dose and temperature have been quantified. This extends work that has previously been reported for the properties of this gel to the effect of measurement temperature on the results. The facilities to perform these measurements were specified, constructed and evaluated as part of the project.The measurement of radiation dose using ultrasound back scatter from an interface between the polymer gel dosimeter and an inert reflector is demonstrated. To enable the measurement of radiation dose using pulse-echo ultrasound methods a novel inert material has been specified, manufactured and characterised. This material is matched to the acoustic impedance of MAGIC gel to produce the most dose-sensitive reflections.The reflections from the interface between the inert reflector and dose-dependent MAGIC gel have been analysed using both a single element transducer and a commercial ultrasound scanner. Both measurement systems demonstrate the same dose and temperature dependence of the ultrasonic reflection. A methodology has been developed to relate pixel values from the ultrasound scanner to the amplitude of the reflected ultrasound signal. A phantom consisting of an array of threads formed from the inert backscattering material has been designed and constructed and a method of extracting pixel data from images of the array acquired using a commercial ultrasound scanner has been developed, so that multiple imaging positions could be used to perform a 3-dimensional assessment of radiation dose distributions.It has been demonstrated that a pulse-echo technique using a commercial ultrasound scanner shows promise for radiation gel dosimetry. Further investigation and alternative polymer gel and inert reflector combinations may improve these techniques.

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Section: Radiochromic Dosimetersmentioning

confidence: 99%

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Atkins

Humphrey

Duck

et al. 2010

J. Phys.: Conf. Ser.

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“…Film post-processing, dosimeter registration and data analysis were performed using CERR (Washington University, St Louis, MO), a Matlab-based software. Though, Babic et al (2008) demonstrated a successful implementation of a 3D gamma analysis, at the time of this investigation, the CERR software did not have a true 3D gamma calculation, so all quantitative analysis between datasets were restricted to a slice-by-slice analysis using line profiles and 2D gamma maps (Low and Dempsey 2003, Low et al 1998). The eventual use of 3D absolute dose analysis is currently being developed and will be the topic of future work.…”

Section: Methodsmentioning

confidence: 99%

Investigation into the feasibility of using PRESAGE™/optical-CT dosimetry for the verification of gating treatments

et al. 2010

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This work presents an investigation into the use of PRESAGE ™ dosimeters with an optical-CT scanner as a 3D dosimetry system for quantitative verification of respiratory-gated treatments. The CIRS dynamic thorax phantom was modified to incorporate a moving PRESAGE ™ dosimetersimulating respiration motion in the lungs. A simple AP/PA lung treatment plan was delivered three times to the phantom containing a different but geometrically identical PRESAGE ™ insert each time. Each delivery represented a treatment scenario: static, motion (free-breathing) and gated. The dose distributions, in the three dosimeters, were digitized by the optical-CT scanner. Improved optical-CT readout yielded an increased signal-to-noise ratio by a factor of 3 and decreased reconstruction artifacts compared with prior work. Independent measurements of dose distributions were obtained in the central plane using EBT film. Dose distributions were normalized to a point corresponding to the 100% isodose region prior to the measurement of dose profiles and gamma maps. These measurements were used to quantify the agreement between measured and ECLIPSE ® dose distributions. Average gamma pass rates between PRESAGE ™ and EBT were >99% (criteria 3% dose difference and 1.2 mm distance-to-agreement) for all three treatments. Gamma pass rates between PRESAGE ™ and ECLIPSE ® 3D dose distributions showed excellent agreement for the gated treatment (100% pass rate), but poor for the motion scenario (85% pass rate). This work demonstrates the feasibility of using PRESAGE ™ /optical-CT 3D dosimetry to verify gating-enabled radiation treatments. The capability of the Varian gating system to compensate for motion in this treatment scenario was demonstrated.

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“…The basic reasons to use EBT2 film are its temporal stability, directional independence and easy for self development. 16 The delivered absolute dose to the mean computed dose values inside the TLD contours were used to compare the measured thermoluminescent dosimeter doses. 13 In our analysis, the irradiated films were sampled at a 0.3 mm × 0.3 mm pixel resolution and compared with the related treatment plan dose distribution.…”

Section: Quality Assurance Tld and Ebt Film Analysismentioning

confidence: 99%

Dosimetric comparison among different head and neck radiotherapy techniques using PRESAGE® dosimeter

Rehman

Iqbal

Tailor

et al. 2015

Int J Cancer Ther Oncol

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Original ArticleAbstract Purpose: The purpose of this analysis was to investigate dose distribution of Three Dimensional Conformal Radiation Therapy (3DCRT), Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) for Head and Neck cancer using 3-dimensional PRESAGE® dosimeter. Method: Computer Tomography (CT) scans of Radiological Physics Center (RPC) Head and Neck anthropomorphic phantom with both RPC standard insert and PRESAGE® insert were acquired separated with Philipp's CT scanner and both CT scans were exported via DICOM to the pinnacle treatment planning system (TPS). Each plan was delivered twice to the RPC phantom first containing the RPC standard insert having Thermoluminescent detectors (TLD) and film dosimeters and then again containing the PRESAGE® insert having three dimensional dosimeter (PRESAGE®) by using a Varian True beam linear accelerator. After irradiation, the standard insert including point dose measurement (TLD) and planner GafChromic® EBT film measurement was read using RPC standard procedure. The 3D dose distribution from PRESAGE® was read out with the Duke Midsized optical scanner dedicated to RPC (DMOS-RPC). Dose volume histogram (DVH), mean and maximal doses for organ-at-risk (OARs) were calculated and compared among each Head and Neck technique. The prescription dose was same for all Head and Neck radiotherapy techniques which was 6.60 Gy per friction. Beam profile comparison and gamma analysis were used to quantify agreement among film measurement, PRESAGE® measurement and calculated dose distribution. Quality assurances of all plans were performed by using ArcCHECK method. Results: VMAT delivered the lowest mean and maximal doses to organ at risk (spinal cord and parotid) than IMRT and 3DCRT. Such dose distribution was verified by absolute dose distribution using TLD system. 2D gamma 5%/3 mm criteria of Pinnacle vs. EBT2 film 3DCRT (92.34%), IMRT (92.3%) and VMAT (96.63%) in axial plan respectively. It was also found that agreement between PRESAGE® and pinnacle along the axial, sagittal and coronal plans VMAT agreement was better than IMRT and 3DCRTplan excludes a 7 mm rim at the edge of the dosimeter using 2D gamma map criteria (±5%/3 mm) with 5% threshold dose. Profile showed good agreement for all plans between film, PRESAGE® and pinnacle. 3D gamma was performed for planning target volume (PTV) and organ at risks (OARs) VMAT and 3DCRT endow with better agreement than IMRT. Conclusion: VMAT delivered lowered mean and maximal doses to organ at risk and better PTV coverage. TLD, EBT film and PRESAGE® dosimeter has suggested that VMAT would be superior modality for the treatment of Head and Neck cancer than IMRT and 3DCRT.

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Three-Dimensional Dose Verification for Intensity-Modulated Radiation Therapy in the Radiological Physics Centre Head-and-Neck Phantom Using Optical Computed Tomography Scans of Ferrous Xylenol–Orange Gel Dosimeters

Cited by 70 publications

References 18 publications

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Investigation into the feasibility of using PRESAGE™/optical-CT dosimetry for the verification of gating treatments

Dosimetric comparison among different head and neck radiotherapy techniques using PRESAGE® dosimeter

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