Rapid MCNP simulation of DNA double strand break (DSB) relative biological effectiveness (RBE) for photons, neutrons, and light ions.
نویسندگان
چکیده
To account for particle interactions in the extracellular (physical) environment, information from the cell-level Monte Carlo damage simulation (MCDS) for DNA double strand break (DSB) induction has been integrated into the general purpose Monte Carlo N-particle (MCNP) radiation transport code system. The effort to integrate these models is motivated by the need for a computationally efficient model to accurately predict particle relative biological effectiveness (RBE) in cell cultures and in vivo. To illustrate the approach and highlight the impact of the larger scale physical environment (e.g. establishing charged particle equilibrium), we examined the RBE for DSB induction (RBEDSB) of x-rays, (137)Cs γ-rays, neutrons and light ions relative to γ-rays from (60)Co in monolayer cell cultures at various depths in water. Under normoxic conditions, we found that (137)Cs γ-rays are about 1.7% more effective at creating DSB than γ-rays from (60)Co (RBEDSB = 1.017) whereas 60-250 kV x-rays are 1.1 to 1.25 times more efficient at creating DSB than (60)Co. Under anoxic conditions, kV x-rays may have an RBEDSB up to 1.51 times as large as (60)Co γ-rays. Fission neutrons passing through monolayer cell cultures have an RBEDSB that ranges from 2.6 to 3.0 in normoxic cells, but may be as large as 9.93 for anoxic cells. For proton pencil beams, Monte Carlo simulations suggest an RBEDSB of about 1.2 at the tip of the Bragg peak and up to 1.6 a few mm beyond the Bragg peak. Bragg peak RBEDSB increases with decreasing oxygen concentration, which may create opportunities to apply proton dose painting to help address tumor hypoxia. Modeling of the particle RBE for DSB induction across multiple physical and biological scales has the potential to aid in the interpretation of laboratory experiments and provide useful information to advance the safety and effectiveness of hadron therapy in the treatment of cancer.
منابع مشابه
The study of dose gamma rays of 192Ir source on DNA single strand break (SSB) and DNA double strand break (DSB) in soft tissue phantom
Introduction: Passage of ionizing radiation through the organs of living creatures develops clusters of damaged nucleotides inside the DNA rounds. 192Ir Gamma source is one of the most widely used sources in brachytherapy of cervical and prostate cancer. Thus, in this research, we investigated the flux of photons and its resulting secondary electrons, the single-strand break (S...
متن کاملEvaluation of the relative biological effectiveness of the Auger electrons produced during gadolinium neutron capture therapy using microdosimetric approach
Determination of the relative biological effectiveness (RBE) of Auger electrons is a challenging task in radiobiology. In this study, we have estimated the RBE of internal conversion (IC) and Auger electrons released during Gadolinium neutron capture reaction (GNCR) by means of biological weighting functions (BWFs) with microdosimetric approach. Regarding the different distribution of Gadoliniu...
متن کاملAn investigation of neutron direct damages at energies of 0.1-2 MeV on the DNA molecules with atomic structure deduced using Geant4 toolkit
This study proposes a method to estimate RBE of fast neutrons using Monte Carlo simulations. This approach is based on the combination of an atomic resolution DNA geometrical model and Monte Carlo simulations for tracking particles. Atomic positions were extracted from the Protein Data Bank. The GEANT4 code was used for tracking the secondary particles generated by fast neutrons during their in...
متن کاملA mechanism-based approach to predict the relative biological effectiveness of protons and carbon ions in radiation therapy.
PURPOSE The physical and potential biological advantages of proton and carbon ions have not been fully exploited in radiation therapy for the treatment of cancer. In this work, an approach to predict proton and carbon ion relative biological effectiveness (RBE) in a representative spread-out Bragg peak (SOBP) is derived using the repair-misrepair-fixation (RMF) model. METHODS AND MATERIALS Fo...
متن کاملEfficient Rejoining of DNA Double-Strand Breaks despite Increased Cell-Killing Effectiveness following Spread-Out Bragg Peak Carbon-Ion Irradiation
Radiotherapy of solid tumors with charged particles holds several advantages in comparison to photon therapy; among them conformal dose distribution in the tumor, improved sparing of tumor-surrounding healthy tissue, and an increased relative biological effectiveness (RBE) in the tumor target volume in the case of ions heavier than protons. A crucial factor of the biological effects is DNA dama...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physics in medicine and biology
دوره 60 21 شماره
صفحات -
تاریخ انتشار 2015