Using the Proton Energy Spectrum and Microdosimetry to Model Proton Relative Biological Effectiveness.
Purpose: We introduce a methodology to calculate the microdosimetric quantity dose-mean lineal energy for input into the microdosimetric kinetic model (MKM) to model the relative biological effectiveness (RBE) of proton irradiation experiments.Methods and Materials: The data from 7 individual proton...
| Published in: | International Journal of Radiation Oncology, Biology, Physics Vol. 104; no. 2; pp. 316 - 325 |
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| Main Authors: | , , , , , , , , , |
| Format: | equations & formulas research tables/charts Journal Article |
| Published: |
Pergamon Press - An Imprint of Elsevier Science
Jun2019
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| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=136087984&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 136087984 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 03603016 1ZQ jtl: International Journal of Radiation Oncology, Biology, Physics issn: 03603016 maglogo: N pubinfo: dt: Jun2019 vid: 104 iid: 2 pid: 2410 pub: Pergamon Press - An Imprint of Elsevier Science artinfo: ui: 136087984 136087984 NLM30731186 136087984 10.1016/j.ijrobp.2019.01.094 NLM30731186 136087984 ppf: 316 ppct: 9 formats: tig: atl: Using the Proton Energy Spectrum and Microdosimetry to Model Proton Relative Biological Effectiveness. aug: au: Newpower, Mark Patel, Darshana Bronk, Lawrence Guan, Fada Chaudhary, Pankaj McMahon, Stephen J. Prise, Kevin M. Schettino, Giuseppe Grosshans, David R. Mohan, Radhe affil: Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas sug: subj: Proton Therapy Protons Energy Transfer Radiation Dosage Systems Analysis Funding Source Human ab: Purpose: We introduce a methodology to calculate the microdosimetric quantity dose-mean lineal energy for input into the microdosimetric kinetic model (MKM) to model the relative biological effectiveness (RBE) of proton irradiation experiments.Methods and Materials: The data from 7 individual proton RBE experiments were included in this study. In each experiment, the RBE at several points along the Bragg curve was measured. Monte Carlo simulations to calculate the lineal energy probability density function of 172 different proton energies were carried out with use of Geant4 DNA. We calculated the fluence-weighted lineal energy probability density function (fw(y)), based on the proton energy spectra calculated through Monte Carlo at each experimental depth, calculated the dose-mean lineal energy yD¯ for input into the MKM, and then computed the RBE. The radius of the domain (rd) was varied to reach the best agreement between the MKM-predicted RBE and experimental RBE. A generic RBE model as a function of dose-averaged linear energy transfer (LETD) with 1 fitting parameter was presented and fit to the experimental RBE data as well to facilitate a comparison to the MKM.Results: Both the MKM and LETD-based models modeled the RBE from experiments well. Values for rd were similar to those of other cell lines under proton irradiation that were modeled with the MKM. Analysis of the performance of each model revealed that neither model was clearly superior to the other.Conclusions: Our 3 key accomplishments include the following: (1) We developed a method that uses the proton energy spectra and lineal energy distributions of those protons to calculate dose-mean lineal energy. (2) We demonstrated that our application of the MKM provides theoretical validation of proton irradiation experiments that show that RBE is significantly greater than 1.1. (3) We showed that there is no clear evidence that the MKM is better than LETD-based RBE models. pubtype: Academic Journal doctype: equations & formulas research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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