Basics of particle therapy I: physics

Abstract

With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest.

Karbon İyonlarının Beyindeki Tümör Bölgesinde Enerji Depolanmasının Monte Carlo Yöntemiyle İncelenmesi

“…Protonlar doza göre nispeten lokalize biyolojik hasara neden olurken, ağır yüklü parçacık demetleri geçtikleri yol boyunca birçok iyon izi üretmekte ve böylece yerel olarak çoklu hasarlara neden olmaktadır. Aslında ağır iyon demetleri için radyobiyolojik etkiyi kapsayan LET'den daha ziyade iyon demetlerinin iz yapısını anlamak gereklidir (Park and Kang 2011).…”

Radiation-Induced Fibrotic Tumor Microenvironment Regulates Anti-Tumor Immune Response

“…However, the differences between the effects of low LET and high LET within the tumor microenvironment (TME) remain unclear [4,5].…”

Density-dependent Energy Loss of Protons in Pb and Be Targets and Percent Mass-Stopping Power from Bethe-Bloch Formula and Bichsel-Sternheimer Data Within 1–12 MeV Energy Range: A Comparative Study Based on Bland-Altman Analysis

“…The energy-loss mechanism of charged particles in various materials has potential applications in nuclear physics, particle physics, biology, and radiation physics/chemistry [1][2][3]. Heavy charged particles such as protons and alpha particles have strong ionization power owing to dominating coulomb interaction with the orbiting electrons of the target material.…”

“…The schematic diagram of atomic ionization due to the incident positive projectile particle of charge ze is shown in Figure 1. It is important to know the energy loss of the projectile in matter for potential applications in certain branches of physics such as atomic physics, solid-state physics, biophysics, particle physics, nuclear physics, and radiation physics [1][2][3][4][5][6][7][8][9]. For instance, experimental particle physicists identify charged particles from energy loss in detector material [2].…”

“…We have focused on the low-energy range as the interaction of low-energy protons and alpha particles with various materials has many promising applications in nuclear and atomic physics, radiation physics, and environmental physics [8,9,18]. Proton beams have advantages over the conventional photon beams, both for low-and high-energy interactions [3]. The classical model of atomic ionization due to Coulomb interaction between its electrons and incident heavy charged particle.…”