WE-H-BRA-09: Application of a Modified Microdosimetric-Kinetic Model to Analyze Relative Biological Effectiveness of Ions Relevant to Light Ion Therapy Using the Particle Heavy Ion Transport System

2016 ◽  
Vol 43 (6Part43) ◽  
pp. 3844-3844
Author(s):  
M Butkus ◽  
T Palmer
Keyword(s):  
Kinetic Model ◽  
Ion Transport ◽  
Transport System ◽  
Relative Biological Effectiveness ◽  
Heavy Ion ◽  
Ion Therapy ◽  
Biological Effectiveness

WE-H-BRA-01: BEST IN PHYSICS (THERAPY): Nano-Dosimetric Kinetic Model for Variable Relative Biological Effectiveness of Proton and Ion Beams

2016 ◽  
Vol 43 (6Part42) ◽  
pp. 3842-3842 ◽  
Author(s):  
R Abolfath ◽  
L Bronk ◽  
Y Helo ◽  
J Schuemann ◽  
U. Titt ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Relative Biological Effectiveness ◽  
Ion Beams ◽  
Biological Effectiveness

scholarly journals Proton RBE dependence on dose in the setting of hypofractionation

2020 ◽  
Vol 93 (1107) ◽  
pp. 20190291 ◽  
Author(s):  
Thomas Friedrich
Keyword(s):  
Relative Biological Effectiveness ◽  
Review Article ◽  
Carbon Ion Therapy ◽  
Carbon Ion ◽  
Ion Therapy ◽  
Therapy Costs ◽  
Biological Effectiveness ◽  
Dose Dependent ◽  
Higher Doses ◽  
Patient Burden

Hypofractionated radiotherapy is attractive concerning patient burden and therapy costs, but many aspects play a role when it comes to assess its safety. While exploited for conventional photon therapy and carbon ion therapy, hypofractionation with protons is only rarely applied. One reason for this is uncertainty in the described dose, mainly due to the relative biological effectiveness (RBE), which is small for protons, but not negligible. RBE is generally dose-dependent, and for higher doses as used in hypofractionation, a thorough RBE evaluation is needed. This review article focuses on the RBE variability in protons and associated issues or implications for hypofractionation.

Responses of synchronous L5178Y S/S cells to heavy ions and their significance for radiobiological theory

1989 ◽  
Vol 237 (1286) ◽  
pp. 27-42 ◽  
Keyword(s):  
Cell Cycle ◽  
Energy Transfer ◽  
Linear Energy Transfer ◽  
Relative Biological Effectiveness ◽  
Survival Curve ◽  
Heavy Ion ◽  
Ion Beams ◽  
X Rays ◽  
Biological Effectiveness ◽  
Ionizing Radiations

Synchronous suspensions of the radiosensitive S/S variant of the L5178Y murine leukaemic lymphoblast at different positions in the cell cycle were exposed aerobically to segments of heavy-ion beams ( 20 Ne, 28 Si, 40 Ar, 56 Fe and 93 Nb) in the Bragg plateau regions of energy deposition. The incident energies of the ion beams were in the range of 460 ± 95 MeV u -1 , and the calculated values of linear energy transfer (LET ∞ ) for the primary nuclei in the irradiated samples were 33 ± 3, 60 ± 3, 95 ± 5, 213 ± 21 and 478 ± 36 keV μm -1 , respectively; 280 kVp X-rays were used as the baseline radiation. Generally, the maxima or inflections in relations between relative biological effectiveness (RBE) and LET ∞ were dependent upon the cycle position at which the cells were irradiated. Certain of those relations were influenced by post-irradiation hypothermia. Irradiation in the cell cycle at mid -G 1 to mid-G 1 +3 h, henceforth called G 1 to G 1 + 3 h, resulted in survival curves that were close approximations to simple exponential functions. As the LET ∞ was increased, the RBE did not exceed 1.0, and by 478 keV μm -1 it had fallen to 0.39. Although similar behaviour has been reported for inactivation of proteins and certain viruses by ionizing radiations, so far the response of the S/S variant is unique for mammalian cells. The slope of the survival curve for X-photons ( D 0 :0.27 Gy) is reduced in G 1 to G 1 + 3 h by post-irradiation incubation at hypothermic temperatures and reaches a minimum ( D 0 : 0.51 Gy) at 25 °C. As the LET ∞ was increased, however, the extent of hypothermic recovery was reduced progressively and essentially was eliminated at 478 keV μm -1 . At the cycle position where the peak of radioresistance to X-photons occurs for S/S cells, G 1 + Sh, increases in LET ∞ elicited only small increases in RBE (at 10% survival), until a maximum was reached around 200 keV μm -1 . At 478 keV μm -1 , what little remained of the variation in response through the cell cycle could be attributed to secondary radiations (δ rays) and smaller nuclei produced by fragmentation of the primary ions. Definitions 1. Linear energy transfer (LET ∞ ) is the energy deposited per unit length of track by an ionizing particle and usually is measured in kiloelectron volts per micrometer (in water). 2. Penumbra . Atomic interactions along the track of a heavy ion result in the ejection of electrons with energies sufficient to move beyond the region of dense ionization which constitutes the track core, and so may be considered to form a penumbra of sparsely ionizing radiations around the track core. 3. RBE . The effectiveness of a densely ionizing radiation (heavy ion) compared to a sparsely ionizing radiation, e. g. X- or γ -photons, is measured by the inverse ratio of the doses of each radiation needed to produce a given radiobiological effect, and is known as the relative biological effectiveness (RBE): the usual reference radiation is 250 kVp X-rays. 4. D 0 is a measure of the radiosensitivity of a cell as determined from the (limiting) linear slope of the survival curve, and is the dose in Gray (1 Gy ≡ 1 Joule kg -1 ) required to reduce the survival at a point anywhere in that region of the survival curve to 37% of its value at that point.

scholarly journals Relation between Lineal Energy Distribution and Relative Biological Effectiveness for Photon Beams according to the Microdosimetric Kinetic Model

2011 ◽  
Vol 52 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Hiroyuki OKAMOTO ◽  
Tatsuaki KANAI ◽  
Yuki KASE ◽  
Yoshitaka MATSUMOTO ◽  
Yoshiya FURUSAWA ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Energy Distribution ◽  
Relative Biological Effectiveness ◽  
Photon Beams ◽  
Lineal Energy ◽  
Biological Effectiveness

A modified microdosimetric kinetic model for relative biological effectiveness calculation

2017 ◽  
Vol 63 (1) ◽  
pp. 015008 ◽  
Author(s):  
Yizheng Chen ◽  
Junli Li ◽  
Chunyan Li ◽  
Rui Qiu ◽  
Zhen Wu
Keyword(s):  
Kinetic Model ◽  
Relative Biological Effectiveness ◽  
Biological Effectiveness

Relative biological effectiveness study of Lipiodol based on microdosimetric-kinetic model

2018 ◽  
Vol 46 ◽  
pp. 89-95 ◽  
Author(s):  
Daisuke Kawahara ◽  
Hisashi Nakano ◽  
Shuichi Ozawa ◽  
Akito Saito ◽  
Tomoki Kimura ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Relative Biological Effectiveness ◽  
Effectiveness Study ◽  
Biological Effectiveness
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