As technology continues to develop, external beam radiation therapy is being employed, with increased conformity, to treat smaller targets. As this occurs, the dosimetry methods and tools employed to quantify these fields for treatment also have to evolve to provide increased spatial resolution. The team at the University of Wollongong has developed a pixelated silicon detector prototype known ...

Hadron beams have attractive growing interest for cancer treatment owing to their high dose localization around the Bragg peak. Heavier-ions such carbon-ion beams, in particular, can realize higher 3D dose localization, compared with a proton beam, owing to a highly biological effect around the Bragg peak and a low multiple scattering effect. Recently, therefore, hadron cancer radiotherapy has ...

9.1 Background to Proton Therapy The use of proton beams for radiation treatment was proposed by Robert R. Wilson in 1946 [286]. Wilson referred to the ballistical aspects of the proton beam dose distribution as a rationale for the new modality. Heavy charged particles such as protons produce an energy deposition profile in tissue which is superior to profiles attainable using photon or electro...

Photons are exponentially attenuated in matter producing high doses close to the surface. Therefore they are not well suited for the treatment of deep seated tumours. Charged particles, in contrast, exhibit a sharp increase of ionisation density close to the end of their range, the so-called Bragg-peak. The depth of the Bragg-peak can be adjusted by varying the particle’s energy. In parallel wi...

Background: Proton-impact metallic nanoparticles, inducing low-energy electrons emission and characteristic X-rays termed as Coulomb nanoradiator effect (CNR), are known to produce therapeutic enhancement in proton treatment on experimental tumors. The purpose of this pilot study was to investigate the effect of CNR-based dose enhancement on tumor growth inhibition in an iron-oxide nanoparticle...

High-Z nano materials have been previously shown to increase the amount of dose deposition within the tumour due to an increase in secondary electrons. This study evaluates the effects of high-Z nano materials in combination with protons, and the impact of proton energy, nanoparticle material and concentration. These effects were studied in silico through Monte Carlo simulation and experimental...

The goal of radiotherapy is to achieve uniform target coverage while sparing normal tissue. In proton therapy, the same sources of geometric uncertainty are present as in conventional radiotherapy. However, an important and fundamental difference in proton therapy is that protons have a finite range, highly dependent on the electron density of the material they are traversing, resulting in a st...

The ionization yield of ion tracks in polymers and biomolecular systems reaches a maximum, known as the Bragg peak, close to the end of the ion trajectories. Along the path of the ions through the materials, many electrons are generated, which produce a cascade of further ionizations and, consequently, a shower of secondary electrons. Among these, very low energy secondary electrons can produce...

A simple analytical model is found that predicts the exact proton spectrum needed to obtain a spread-out-Bragg peak (SOBP) distribution for laser-accelerated proton beams. The theory is based on the solution to the Boltzmann kinetic equation for the proton distribution function. The resulting analytical expression allows one to calculate the SOBP proton energy spectra for the different beamlet ...

Chin J Cancer Res 2013;25(3):267-268 www.thecjcr.org In the mid 1940s, Robert Wilson (1) hypothesized that a highly localized deposition of energy from a proton beam could be used to increase the radiation dose to tumors while minimizing radiation to adjacent normal tissues. The depthdose distribution of a proton beam differs significantly from that of a photon beam. Protons show increasing ene...