Comparative dosimetry of GammaMed Plus high-dose rate <sup>192</sup> Ir brachytherapy source

Patel, Naiya; Majumdar, B.; Vijayan,

doi:10.4103/0971-6203.66761

Cited by 7 publications

(5 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[31] A Monte Carlo simulation, which is the dose calculation algorithm used in this study, is capable of calculating heterogeneous medium accurately. [3233] Therefore, even when air exists in the rectum [Figure 2a], the physical dose can be obtained with high accuracy. Our method uses PHITS coupled with MKM, which is a dose evaluation method that can obtain both a biological dose and a physical dose.…”

Section: Discussionmentioning

confidence: 99%

Establishment of a new three-dimensional dose evaluation method considering variable relative biological effectiveness and dose fractionation in proton therapy combined with high-dose-rate brachytherapy

et al. 2019

View full text Add to dashboard Cite

Purpose:The purpose of this study is to evaluate the influence of variable relative biological effectiveness (RBE) of proton beam and dose fractionation has on dose distribution and to establish a new three-dimensional dose evaluation method for proton therapy combined with high-dose-rate (HDR) brachytherapy.Materials and Methods:To evaluate the influence of variable RBE and dose fractionation on dose distribution in proton beam therapy, the depth-dose distribution of proton therapy was compared with clinical dose, RBE-weighted dose, and equivalent dose in 2 Gy fractions using a linear-quadratic-linear model (EQD2LQL). The clinical dose was calculated by multiplying the physical dose by RBE of 1.1. The RBE-weighted dose is a biological dose that takes into account RBE variation calculated by microdosimetric kinetic model implemented in Monte Carlo code. The EQD2LQL is a biological dose that makes the RBE-weighted dose equivalent to 2 Gy using a linear-quadratic-linear (LQL) model. Finally, we evaluated the three-dimensional dose by taking into account RBE variation and LQL model for proton therapy combined with HDR brachytherapy.Results:The RBE-weighted dose increased at the distal of the spread-out Bragg peak (SOBP). With the difference in the dose fractionation taken into account, the EQD2LQL at the distal of the SOBP increased more than the RBE-weighted dose. In proton therapy combined with HDR brachytherapy, a divergence of 103% or more was observed between the conventional dose estimation method and the dose estimation method we propose.Conclusions:Our dose evaluation method can evaluate the EQD2LQL considering RBE changes in the dose distribution.

show abstract

Section: Discussionmentioning

confidence: 99%

Establishment of a new three-dimensional dose evaluation method considering variable relative biological effectiveness and dose fractionation in proton therapy combined with high-dose-rate brachytherapy

et al. 2019

View full text Add to dashboard Cite

show abstract

“…In a similar study, Patel et al . [21] measured the radial dose function using a PTW Semiflex chamber for a different normalizing point, with a distance of 1 and 5 cm from the source, and the standard deviations were found to be 2–5% and 2%, respectively. A larger deviation was observed at the 1 cm normalizing point.…”

Section: Discussionmentioning

confidence: 99%

Dosimetric impact of an air passage on intraluminal brachytherapy for bronchus cancer

Okamoto¹,

Wakita²,

Nakamura³

et al. 2016

Journal of Radiation Research

View full text Add to dashboard Cite

The brachytherapy dose calculations used in treatment planning systems (TPSs) have conventionally been performed assuming homogeneous water. Using measurements and a Monte Carlo simulation, we evaluated the dosimetric impact of an air passage on brachytherapy for bronchus cancer. To obtain the geometrical characteristics of an air passage, we analyzed the anatomical information from CT images of patients who underwent intraluminal brachytherapy using a high-dose-rate 192Ir source (MicroSelectron V2r®, Nucletron). Using an ionization chamber, we developed a measurement system capable of measuring the peripheral dose with or without an air cavity surrounding the catheter. Air cavities of five different radii (0.3, 0.5, 0.75, 1.25 and 1.5 cm) were modeled by cylindrical tubes surrounding the catheter. A Monte Carlo code (GEANT4) was also used to evaluate the dosimetric impact of the air cavity. Compared with dose calculations in homogeneous water, the measurements and GEANT4 indicated a maximum overdose of 5–8% near the surface of the air cavity (with the maximum radius of 1.5 cm). Conversely, they indicated a minimum overdose of ~1% in the region 3–5 cm from the cavity surface for the smallest radius of 0.3 cm. The dosimetric impact depended on the size and the distance of the air passage, as well as the length of the treatment region. Based on dose calculations in water, the TPS for intraluminal brachytherapy for bronchus cancer had an unexpected overdose of 3–5% for a mean radius of 0.75 cm. This study indicates the need for improvement in dose calculation accuracy with respect to intraluminal brachytherapy for bronchus cancer.

show abstract

“…However, according to a prior study, TLD's appropriateness for brachytherapy dosimetry was determined by high-precision measurements using some of the most regularly utilised brachytherapy sources (DeWerd et al, 2014). Apart from these dosimeters, Monte Carlo calculation has been reported as a reliable and preferable dosimetry system, and it is also commonly utilised in obtaining dosimetric data for brachytherapy sources (Patel et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Dose Distribution of 192Ir HDR Brachytherapy Source Measurement using Gafchromic® EBT3 Film Dosimeter and TLD-100H

Shukor¹,

Musarudin²,

Abdullah³

et al. 2022

JST

View full text Add to dashboard Cite

This study aims to measure the radial dose function and anisotropy function F(r, θ) of high Dose Rate (HDR) 192Ir source in a fabricated water-equivalent phantom using Gafchromic® EBT3 film and TLD-100H and to compare the results obtained with the MCNP5 calculated values. The phantom was fabricated using Perspex PMMA material. For, the EBT3 films with a required dimension and TLD-100H chips were placed at r=1, 2, 3, 5, and 10 cm from the source. The F(r, θ) measurements were carried out at r=1, 2, 3, 5, and 10 cm with the angle range from 10° to 170°. The result of from EBT3 film and TLD-100H was in good agreement (2.10%±1.99). Compared to MCNP5, the differences are within 0.31% to 11.47% for EBT3 film and 0.08% to 10.58% for TLD-100H. For the F(r, θ), an average deviation with the MCNP5 calculation is 4.94%±2.7. For both and F(r, θ), the effects are prominent at r=10 cm. At this distance, the response of both Gafchromic® EBT3 film and TLD-100H shows less sensitivity as the dose followed the inverse square law. This work demonstrates that Gafchromic® EBT3 film dosimeter and TLD-100H are suitable dosimeters in 192Ir dosimetric measurements at a radial distance of ˂5 cm

show abstract

Comparative dosimetry of GammaMed Plus high-dose rate ¹⁹² Ir brachytherapy source

Cited by 7 publications

References 22 publications

Establishment of a new three-dimensional dose evaluation method considering variable relative biological effectiveness and dose fractionation in proton therapy combined with high-dose-rate brachytherapy

Establishment of a new three-dimensional dose evaluation method considering variable relative biological effectiveness and dose fractionation in proton therapy combined with high-dose-rate brachytherapy

Dosimetric impact of an air passage on intraluminal brachytherapy for bronchus cancer

Dose Distribution of 192Ir HDR Brachytherapy Source Measurement using Gafchromic® EBT3 Film Dosimeter and TLD-100H

Contact Info

Product

Resources

About

Comparative dosimetry of GammaMed Plus high-dose rate 192 Ir brachytherapy source

Cited by 7 publications

References 22 publications

Establishment of a new three-dimensional dose evaluation method considering variable relative biological effectiveness and dose fractionation in proton therapy combined with high-dose-rate brachytherapy

Establishment of a new three-dimensional dose evaluation method considering variable relative biological effectiveness and dose fractionation in proton therapy combined with high-dose-rate brachytherapy

Dosimetric impact of an air passage on intraluminal brachytherapy for bronchus cancer

Dose Distribution of 192Ir HDR Brachytherapy Source Measurement using Gafchromic® EBT3 Film Dosimeter and TLD-100H

Contact Info

Product

Resources

About

Comparative dosimetry of GammaMed Plus high-dose rate ¹⁹² Ir brachytherapy source