Dependence and independence of survival parameters on linear energy transfer in cells and tissues

Andō, Kōichi; Goodhead, Dudley T.

doi:10.1093/jrr/rrw058

Cited by 19 publications

(17 citation statements)

References 41 publications

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“…Since d is not dependent on LET, this implies b ion = b R up to at least 50 keV/lm. Others 68,96 have found no systematic increase or decrease in b ion with increasing LET. Furthermore, if the ratio (a/b) R is known, the value of the domain diameter d can be determined from the slope of the linear relation of Eq.…”

Section: B Mk Modelmentioning

confidence: 93%

“…The MK model of Hawkins, the most recent version of the LEM, and the RMF model are examples of mechanism‐inspired models that link the RBE for reproductive cell survival to the induction and biological processing of sublethal damage, especially the DNA DSB, into more lethal forms of damage, such as chromosome aberrations. The MK, LEM, and RMF models all aim to derive the biological effects of ion radiation from the response of cells or tissues to low LET photons, thus efficiently exploiting the large amount of in vitro and in vivo data in the literature . All three models provide quantitative frameworks to estimate trends in the LQ model radiation sensitivity parameters α, β (or α/β) as a function of linear energy transfer (LET), lineal energy ( y ), or other metrics of radiation quality, such as the square of the ratio of the effective charge of the ion ( Z eff ) divided by the speed of the ion relative to the speed of light (β).…”

Section: Rbe Models and Mechanisms Of Actionmentioning

confidence: 99%

“…Values of (α/β) R for an array of normal tissue and malignant cell populations have been measured and tabulated . Because of the limited range of values of the domain diameter, RBE 1 can be estimated with some degree of confidence from Eq.…”

Section: Rbe Models and Mechanisms Of Actionmentioning

confidence: 99%

“…The MK, LEM, and RMF models all aim to derive the biological effects of ion radiation from the response of cells or tissues to low LET photons, thus efficiently exploiting the large amount of in vitro and in vivo data in the literature. 35,[67][68][69][70][71][72][73] All three models provide quantitative frameworks to estimate trends in the LQ model radiation sensitivity parameters a, b (or a/b) as a function of linear energy transfer (LET), lineal energy (y), or other metrics of radiation quality, such as the square of the ratio of the effective charge of the ion (Z eff ) divided by the speed of the ion relative to the speed of light (b). In general, particle LET (and lineal energy) increases with increasing (Z eff /b) 2 up to a particle-specific peak and then begins to decrease.…”

Section: Rbe Models and Mechanisms Of Actionmentioning

confidence: 99%

“…97 Values of (a/b) R for an array of normal tissue and malignant cell populations have been measured and tabulated. 35,[67][68][69][70][71][72][73] Because of the limited range of values of the domain diameter, RBE 1 can be estimated with some degree of confidence from Eq. (5) for LET up to about 50-75 keV/ lm, using an average value of d equal 0.70 lm, and a value of the (a/b) R ratio appropriate to the irradiated population of interest.…”

Section: B Mk Modelmentioning

confidence: 99%

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A comparison of mechanism‐inspired models for particle relative biological effectiveness (RBE)

et al. 2018

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Background and Significance The application of heavy ion beams in cancer therapy must account for the increasing relative biological effectiveness (RBE) with increasing penetration depth when determining dose prescriptions and organ at risk (OAR) constraints in treatment planning. Because RBE depends in a complex manner on factors such as the ion type, energy, cell and tissue radiosensitivity, physical dose, biological endpoint, and position within and outside treatment fields, biophysical models reflecting these dependencies are required for the personalization and optimization of treatment plans. Aim To review and compare three mechanism‐inspired models which predict the complexities of particle RBE for various ion types, energies, linear energy transfer (LET) values and tissue radiation sensitivities. Methods The review of models and mechanisms focuses on the Local Effect Model (LEM), the Microdosimetric‐Kinetic (MK) model, and the Repair‐Misrepair‐Fixation (RMF) model in combination with the Monte Carlo Damage Simulation (MCDS). These models relate the induction of potentially lethal double strand breaks (DSBs) to the subsequent interactions and biological processing of DSB into more lethal forms of damage. A key element to explain the increased biological effectiveness of high LET ions compared to MV x rays is the characterization of the number and local complexity (clustering) of the initial DSB produced within a cell. For high LET ions, the spatial density of DSB induction along an ion's trajectory is much greater than along the path of a low LET electron, such as the secondary electrons produced by the megavoltage (MV) x rays used in conventional radiation therapy. The main aspects of the three models are introduced and the conceptual similarities and differences are critiqued and highlighted. Model predictions are compared in terms of the RBE for DSB induction and for reproductive cell survival. Results and Conclusions Comparisons of the RBE for DSB induction and for cell survival are presented for proton (1H), helium (4He), and carbon (12C) ions for the therapeutically most relevant range of ion beam energies. The reviewed models embody mechanisms of action acting over the spatial scales underlying the biological processing of potentially lethal DSB into more lethal forms of damage. Differences among the number and types of input parameters, relevant biological targets, and the computational approaches among the LEM, MK and RMF models are summarized and critiqued. Potential experiments to test some of the seemingly contradictory aspects of the models are discussed.

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Section: B Mk Modelmentioning

confidence: 93%

Section: Rbe Models and Mechanisms Of Actionmentioning

confidence: 99%

Section: Rbe Models and Mechanisms Of Actionmentioning

confidence: 99%

Section: Rbe Models and Mechanisms Of Actionmentioning

confidence: 99%

Section: B Mk Modelmentioning

confidence: 99%

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A comparison of mechanism‐inspired models for particle relative biological effectiveness (RBE)

et al. 2018

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The Radiobiology of Particle Therapy

Fossati¹,

Tubin²,

Hug³

2022

Principles and Practice of Particle Therapy

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Radiobiological Implications of Nanoparticles Following Radiation Treatment

Ahmad

Schettino

Royle

et al. 2020

Part & Part Syst Charact

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clinically due to the number of variables that need to be investigated to control and optimize the effect. Various groups have investigated different aspects, such as varying NP size or radiation beam energy. Even with knowledge from these studies, there is still a considerable amount of variability in reported findings. Differences are caused by the diversity in cell lines, NPs with their respective coatings, incubated NP concentrations, incubation times, irradiation parameters, as well as the assays used to demonstrate the effects. This has led to variations in the results, where significant enhancements of a factor of 25 were shown by Rahman et al., with Aurovist 1.9 nm gold nanoparticles (AuNPs) at a concentration of 1 mm with bovine aortic endothelial cells (BAEC) and 80 kV X-rays, [3] compared to smaller enhancements shown by Chithrani et al., where they synthesized 50 nm AuNPs at a concentration of approximately 1 nm in HeLa cells and found an enhancement factor of 1.17 with 6 MV X-rays. [4] As well as this, there are also differences in protocols between research groups, in both maintenance of cells and assays reported.A review by Her et al. reported on the different mechanisms associated with NP-enhanced radiotherapy, where the overall effect is a combination of physical, chemical, and biological -7 and U87) and three commercially available nanoparticles (gold, gadolinium, and iron oxide) irradiated by 6 MV X-rays. To assess cell survival, clonogenic assays are carried out for all variables considered, with a concentration of 0.5 mg mL -1 for each nanoparticle material used. This study demonstrates differences in cell survival between nanoparticles and cell line. U87 shows the greatest enhancement with gadolinium nanoparticles (2.02 ± 0.36), whereas MCF-7 cells have higher enhancement with gold nanoparticles (1.74 ± 0.08). Materials with a high atomic number (Z) are shown to cause an increase in the level of cell kill by ionizing radiation when introduced into tumor cells. This study uses in vitro experiments to investigate the differences in radiosensitization between two cell lines (MCFMass spectrometry, however, shows highest elemental uptake with iron oxide and U87 cells with 4.95 ± 0.82 pg of iron oxide per cell. A complex relationship between cellular elemental uptake is demonstrated, highlighting an inverse correlation with the enhancement, but a positive relation with DNA damage when comparing the same nanoparticle between the two cell lines.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.

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Dependence and independence of survival parameters on linear energy transfer in cells and tissues

Cited by 19 publications

References 41 publications

A comparison of mechanism‐inspired models for particle relative biological effectiveness (RBE)

A comparison of mechanism‐inspired models for particle relative biological effectiveness (RBE)

The Radiobiology of Particle Therapy

Radiobiological Implications of Nanoparticles Following Radiation Treatment

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