Denser ionisation clustering and complex DNA damage in proton Bragg peaks far exceeds that seen with conventional X-rays. This results in more efficient cell sterilisation, quantified by the relative biological effectiveness (RBE). Currently, a 1.1 RBE is used to determine the clinical proton doses by dividing the usual X-rays dose by this amount. This number, derived from short-term experiment...

The NCRP has recently defined RBE values and a new quantity (Gy-Eq) for use in estimation of deterministic effects in space shielding and operations. The NCRP's RBE for neutrons is left ambiguous and not fully defined. In the present report we will suggest a complete definition of neutron RBE consistent with the NCRP recommendations and evaluate attenuation properties of deterministic effects (...

Experiments have established that different radiation types have different magnitudes of biological response. When biological response is defined in terms of the Relative Biologic Effectiveness (RBE) and different radiation type is characterized by Linear Energy Transfer (LET), the plot of the RBE versus LET (RBE-LET) curve shows RBE to increase with increasing LET, to reach a maximum, and to d...

Various types of radiation are utilized in the treatment of cancer. Equal physical doses of different radiation types do not always result in the same amount of biological damage. In order to account for these differences, a scaling factor known as the relative biological effectiveness (RBE) can be used. 137Cesium (137Cs) has been used as a source of radiation in a significant body of radiation...

The computation of the relative biological effectiveness (RBE) is a fundamental step in planning cancer radiotherapy treatments with accelerated ions. Numerical parameters derived analyzing dose response chosen cell line after irradiation to photons (i.e., α and β, namely linear quadratic terms linear-quadratic model survival) are generally used as input biophysical models predict ion RBE. α/β ...

Background: The assessment of RBE quantity in the treatment of cancer tumors with proton beams in treatment planning systems (TPS) is of high significance. Given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1.Objective: The main objective of this study was to assess RBE quantity of proton beams and their variations ...

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...

Figure 6 illustrates the simplified RBE model (equation 3) used in this work. Figure 6a shows 9 the physical dose di for 10 9 protons for a single pencil beam, delivering approximately 4.5 10 Gy at the Bragg peak, which is located at the distal edge of the target volume. Figure 6b 11 shows the additional biological dose c L̄idi in Gy for c = 0.04 μm/keV. The sum of c L̄idi and 12 di yields the RB...

Social relationships affect empathy in humans such that empathic neural responses to perceived pain were stronger to racial in-group members than to racial out-group members. Why does the racial bias in empathy (RBE) occur and how can we reduce it? We hypothesized that perceiving an other-race person as a symbol of a racial group, rather than as an individual, decreases references to his/her pe...

OBJECTIVE Evidence indicates that medical graduates with a rural background are more likely to become rural doctors than those with an urban background (the rural background effect (RBE)). Exactly why this is so has rarely been studied. This study sought to identify the role of social, environmental and economic factors in addition to isolation characterising rural environments that either expl...