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In a prostate patient, we found that dose calculation without considering partial shining effect underestimated the femoral head and skin dose.Д¬alculation of the effective dose from natural radioactivity in soil using MCNP code.Д®ffective dose delivered by photon emitted from natural radioactivity in soil was calculated in this work. Our algorithm fitted the measured SOBP at the proximal and entrance regions much better than the ones without considering partial shining effect for all SOBPs of the eight options. The SOBPs of eight options, which are used to label different combinations of proton-beam energy and scattering devices, were calculated with the generated effective weights. A weight-splitting process was then performed to generate a set of effective modulator weights with the partial shining effect incorporated. Next, protons spilled from the accelerator reaching the modulator wheel were simplified as a circular spot of uniform intensity. First, a set of apparent modulator weights was calculated without considering partial shining. In this work, we developed an algorithm that can be used to model this effect and to allow for dose calculations that better fit the measured SOBP. If the SOBP is adjusted to better fit the plateau region, the entrance dose is likely to be underestimated. Proton dose calculation algorithms normally do not consider the partial shining effect, and thus overestimate the dose at the proximal shoulder of spread-out Bragg peak (SOBP) compared with the measurement. We have observed that a proton beam spot may shine on multiple steps of the RMW. Gillin, Michael Mohan, RadheДЄ range modulator wheel (RMW) is an essential component in passively scattered proton therapy. Li, Yupeng Zhang, Xiaodong Fwu Lii, Ming Sahoo, Narayan Zhu, Ron X. Incorporating partial shining effects in proton pencil-beam dose calculation The required calculation times are substantially lower than for pure Monte Carlo calculations. It is demonstrated that the hybrid algorithm can efficiently calculate even complicated pencil beam and cross firing beam geometries. In particular for inhomogeneous materials the hybrid dose calculation algorithm out-performs purely convolution based dose calculation approaches. The accuracy of the developed algorithm is comparable to conventional pure Monte Carlo calculations. In various examples the performance of the algorithm is compared to purely Monte Carlo and purely kernel based dose calculations.

In this work a hybrid dose calculation approach is presented that is based on a combination of Monte Carlo and kernel based dose calculation. In order to launch first clinical trials, accurate and efficient dose calculation methods are an inevitable prerequisite. Abundant preclinical evidence demonstrates that MRT spares normal tissue more effectively than conventional radiation therapy, at equivalent tumour control. Microbeam radiation therapy (MRT) is still a preclinical approach in radiation oncology that uses planar micrometre wide beamlets with extremely high peak doses, separated by a few hundred micrometre wide low dose regions. Hybrid dose calculation: a dose calculation algorithm for microbeam radiation therapyДonzelli, Mattia BrГѓВ¤uer-Krisch, Elke Oelfke, Uwe Wilkens, Jan J. This allows them to be directly applicable to modern spacecraft shielding geometries. The results obtained will provide information on how the shielding performs with many thicknesses of each material in the slab. Water is used to simulate the soft tissues that compose the human body. The shielding geometry used in the dose calculations is a layered slab design, consisting of aluminum, polyethylene, and water.

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Monte carlo simulations run with the particle transport code FLUKA, give absorbed and equivalent dose data for relevant shielding.

This is important in preventing long-term, stochastic radiation effects in humans spending time in space.

Dose equivalent takes into account an absorbed dose of radiation and the biological effectiveness of ionizing radiation. However, in order to calculate effective dose, dose equivalent calculations are needed. It is important to model how shielding designs on spacecraft reduce radiation effective dose pre-flight, and determine whether or not a danger to humans is presented. While in orbit, Astronauts are exposed to a much higher dose of ionizing radiation than when on the ground. Absorbed Dose and Dose Equivalent Calculations for Modeling Effective Dose

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