Investigation of the feasibility of relative 3D dosimetry in the Radiologic Physics Center Head and Neck IMRT phantom using Presage/optical‐CT

Sakhalkar, H; Sterling, David A.; Adamovics, J; Ibbott, Geoffrey S.; Oldham, Mark

doi:10.1118/1.3148534

Cited by 50 publications

(40 citation statements)

References 24 publications

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“…It has been noted in previous studies that there exists a volume effect where sensitivity and response over time may differ subtly based on the volume of the dosimeter. 7,10 An in depth examination of these volume effects is beyond the scope of this work, but as shown in Fig. 9 and discussed below, linear response over time was confirmed for the large volume cylindrical dosimeters for this study.…”

Section: B2b Relative Temporal Stability In Dosimetersmentioning

confidence: 99%

“…As previously published, sensitivity differences have been observed between measurements in small volume optical cuvettes versus larger dosimeters. 7,10 Consequently, calibration curves derived from small volume cuvettes have been found to result in dose discrepancies of 4%-7% when applied to large volume dosimeters. Thus, measured dose distributions were calibrated with corresponding cuvette-based calibrations, then normalized to the central high dose region.…”

Section: D2 Analysis Methodsmentioning

confidence: 99%

“…The two formulations of PRESAGE R (SS1 and SS2) undergoing study in the current work have improved water equivalence with lower Z eff values of 8.08 (SS1) and 7.86 (SS2). The compositions of both of these PRESAGE R formulations under study, as well as that of the earlier formulation from Sakhalkar et al, 7,8 are shown in Table I. PRESAGE R formulations SS1 and SS2 differ from each other only in initiator content and percentage.…”

Section: A Presage Rmentioning

confidence: 99%

“…5 and 6) and has demonstrated potential for use in remote dosimetry applications. 7,8 A previously published study 7 demonstrated the feasibility of using PRESAGE R /Optical-CT for relative 3D dosimetry in the credentialing tests with the RPC IMRT H&N phantom. In this study, the RPC H&N phantom was taken through the entire credentialing treatment planning and delivery procedure both with the standard RPC insert (containing 3 pieces of radiochromic EBT film and 8 TLDs) and with PRESAGE R in lieu of the standard insert.…”

Section: Introductionmentioning

confidence: 99%

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On the feasibility of comprehensive high-resolution 3D remote dosimetry

et al. 2014

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Purpose: This study investigates the feasibility of remote high-resolution 3D dosimetry with the PRESAGE R /Optical-CT system. In remote dosimetry, dosimeters are shipped out from a central base institution to a remote institution for irradiation, then shipped back to the base institution for subsequent readout and analysis. Methods: Two nominally identical optical-CT scanners for 3D dosimetry were constructed and placed at the base (Duke University) and remote (Radiological Physics Center) institutions. Two formulations of PRESAGE R (SS1, SS2) radiochromic dosimeters were investigated. Higher sensitivity was expected in SS1, which had higher initiator content (0.25% bromotrichloromethane), while greater temporal stability was expected in SS2. Four unirradiated PRESAGE R dosimeters (two per formulation, cylindrical dimensions 11 cm diameter, 8.5-9.5 cm length) were imaged at the base institution, then shipped to the remote institution for planning and irradiation. Each dosimeter was irradiated with the same simple treatment plan: an isocentric 3-field "cross" arrangement of 4 × 4 cm open 6 MV beams configured as parallel opposed laterals with an anterior beam. This simple plan was amenable to accurate and repeatable setup, as well as accurate dose modeling by a commissioned treatment planning system (Pinnacle). After irradiation and subsequent (within 1 h) optical-CT readout at the remote institution, the dosimeters were shipped back to the base institution for remote dosimetry readout 3 days postirradiation. Measured on-site and remote relative 3D dose distributions were registered to the Pinnacle dose calculation, which served as the reference distribution for 3D gamma calculations with passing criteria of 5%/2 mm, 3%/3 mm, and 3%/2 mm with a 10% dose threshold. Gamma passing rates, dose profiles, and color-maps were all used to assess and compare the performance of both PRESAGE R formulations for remote dosimetry. Results: The best agreements between the Pinnacle plan and dosimeter readout were observed in PRESAGE R formulation SS2. Under 3%/3 mm 3D gamma passing criteria, passing rates were 91.5% ± 3.6% (SS1) and 97.4% ± 2.2% (SS2) for immediate on-site dosimetry, 96.7% ± 2.4% (SS1) and 97.6% ± 0.6% (SS2) for remote dosimetry. These passing rates are well within TG119 recommendations (88%-90% passing). Under the more stringent criteria of 3%/2 mm, there is a pronounced difference [8.0 percentage points (pp)] between SS1 formulation passing rates for immediate and remote dosimetry while the SS2 formulation maintains both higher passing rates and consistency between immediate and remote results (differences ≤ 1.2 pp) at all metrics. Both PRESAGE R formulations under study maintained high linearity of dose response (R 2 > 0.996) for 1-8 Gy over 14 days with response slope consistency within 4.9% (SS1) and 6.6% (SS2), and a relative dose distribution that remained stable over time was demonstrated in the SS2 dosimeters. Conclusions: Remote 3D dosimetry was shown to be feasible with a PRESAGE R dosimeter formulat...

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Section: B2b Relative Temporal Stability In Dosimetersmentioning

confidence: 99%

Section: D2 Analysis Methodsmentioning

confidence: 99%

Section: A Presage Rmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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On the feasibility of comprehensive high-resolution 3D remote dosimetry

et al. 2014

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“…1 The scattering and absorption properties of the radiation dosimeter should be comparable to the water. 2 The radiological properties and the formulation have been studies by many writers and it was observed that PRESAGE ® (Heuris Inc., Skillman, NJ) has effective atomic number (7.6) close to water (7.42). 3 PRESAGE ® is a radiochromic three dimensional dose measuring dosimeter which is composed of polyurethane and radiochromic components (Leuco dyes) and halogen containing free radical initiator 4 that have an optical attenuation coefficient that changes linearly with absorbed dose.…”

Section: Introductionmentioning

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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Dosimetric characterization of a body‐conforming radiochromic sheet

Wang

Dona

Liu

et al. 2020

J Applied Clin Med Phys

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Purpose A novel radiochromic PRESAGE sheet (Heuris Inc.) with 3 mm thickness has been developed as a measurement tool for 2D dosimetry. Its inherent ability to conform to irregular surfaces makes this dosimeter advantageous for patient surface dosimetry. This study is a comprehensive investigation into the PRESAGE sheet’s dosimetric characteristic, accuracy and its potential use as a dosimeter for clinical applications. Methods The characterization of the dosimeter included evaluation of the temporal stability of the dose linearity, reproducibility, measurement uncertainties, dose rate, energy, temperature and angular dependence, lateral response artifacts, percent depth dose curve, and 2D dose measurement. Dose distribution measurements were acquired for regular square fields on a flat and irregular surface and an irregular modulated field on the smooth surface. All measurements were performed using an Epson 11000XL high‐resolution scanner. Results The examined dosimeters exhibit stable linear response, standard error of repeated measurements within 2%, negligible dose rate, energy, and angular dependence. The same linear dose response was measured while the dosimeter was in contact with a heated water surface. Gamma test and histogram analysis of the dose difference between PRESAGE and EBT3 film, PRESAGE and the treatment planning system (TPS) were used to evaluate the measured dose distributions. The PRESAGE sheet dose distributions showed good agreement with EBT3 film and TPS. A discrepancy smaller than the statistical error of the two dosimeters was reported. Conclusions This study established a full dosimetric characterization of the PRESAGE sheets with the purpose of laying the foundation for future clinical uses. The results presented here for the comparison of this novel dosimeter with those currently in use reinforce the possibility of using this dosimeter as an alternative for irregular surface dose measurements.

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Investigation of the feasibility of relative 3D dosimetry in the Radiologic Physics Center Head and Neck IMRT phantom using Presage/optical‐CT

Cited by 50 publications

References 24 publications

On the feasibility of comprehensive high-resolution 3D remote dosimetry

On the feasibility of comprehensive high-resolution 3D remote dosimetry

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

Dosimetric characterization of a body‐conforming radiochromic sheet

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