1. Figure 5 The biological effects of charged particles
depend on ionization density (linear energy transfer (LET))
Figure 5 | The biological effects of charged particles depend on ionization density (linear energy transfer (LET)). Particles with high LET produce clustered regions of damage, which are difficult to repair. Cells derived from a patient with osteosarcoma and cultured in vitro were exposed to (panel a) X-rays, or (panel b) carbon ions at the Universal Linear Accelerator (UNILAC) centre of the GSI Helmholtz Center for Heavy Ion Research (Darmstadt, Germany), resulting in DNA double-strand breaks (visualized in green via immunofluorescence staining of histone γH2AX). The physical differences in energy deposition patterns (random for photons, along tracks for particles) cause the different distributions of DNA lesions that are observed in the cells. c | DNA damage leads to chromosomal aberrations, which can be visualized during the first mitotic division following radiation. This image shows a DNA-damaged peripheral blood lymphocyte from a patient treated with carbon-ion radiotherapy. Chromosomes 2 and 4 were stained in green and orange, respectively, using fluorescence in situ hybridization (FISH), while the other chromosomes were counterstained using DAPI (blue). d | Fraction of lymphocytes carrying aberrations in chromosomes 2 or 4 (visualized using FISH-staining) as a function of the tumour radiation dose received by patients with uterine cancer treated with X-rays or carbon ions at the Japanese National Institute for Radiological Sciences (NIRS, Chiba, Japan). The target volume was similar for all patients. Aberrations were visualized as shown in panel c. The curves show trends averaged from at least three patients. Images in panels a and b courtesy of Annabelle Becker, PhD thesis, TU Darmstadt, Germany. The photomicrograph in panel c was obtained with a Nikon fluorescence microscope at NIRS, Japan. The results plotted in panel d were reported in Ref. 111 (Durante, M. et al. X-Rays versus carbon-ion tumour therapy: cytogenetic damage in lymphocytes. Int. J. Radiat. Oncol. Biol. Phys. 47, 793–798 (2000)).
The results plotted in panel d were reported in REF. 112 (Durante, M. et al. X‑Rays
versus carbon-ion tumour therapy: cytogenetic damage in lymphocytes. Int. J. Radiat. Oncol. Biol. Phys. 47, 793–798 (2000)).
Durante, M. et al. (2017) Charged-particle therapy in cancer: clinical uses and future perspectives
Nat. Rev. Clin. Oncol. doi: /nrclinonc