Nano-scale processes behind ion-beam cancer therapy

Eur. Phys. J. D (2016) 70: 86 DOI: 10.1140/epjd/e2016-70156-y THE EUROPEAN PHYSICAL JOURNAL D Editorial Nano-scale processes behind ion-beam cancer therapy Eugene Surdutovich1 , Gustavo Garcia2 , Nigel Mason3 , and Andrey V. Solov’yov4,a 1 Department of Physics, Oakland University, Rochester, Michigan 48309, USA Instituto de Fisica Fundamental, CSIC, Serrano 113-bis, 28006 Madrid, Spain 3 Deptartment of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK 4 MBN Research Center, Altenhoferallee 3, 60438 Frankfurt am Main, Germany 2 Received 1 March 2016 c EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2016 Published online 14 April 2016 –  Abstract. This topical issue collates a series of papers based on new data reported at the third Nano-IBCT Conference of the COST Action MP1002: Nanoscale Insights into Ion Beam Cancer Therapy, held in Boppard, Germany, from October 27th to October 31st, 2014. The Nano-IBCT COST Action was launched in December 2010 and brought together more than 300 experts from different disciplines (physics, chemistry, biology) with specialists in radiation damage of biological matter from hadron-therapy centres, and medical institutions. This meeting followed the first and the second conferences of the Action held in October 2011 in Caen, France and in May 2013 in Sopot, Poland respectively. This conference series provided a focus for the European research community and has highlighted the pioneering research into the fundamental processes underpinning ion beam cancer therapy. 1 Introduction Ion beam cancer therapy (IBCT, or hadron therapy) represents an effective method for providing high-dose delivery into tumours, thereby maximizing the probability of killing the cancer cells whilst simultaneously minimizing the radiation damage to surrounding healthy tissue [1–3]. Despite its high cost, proton-beam therapy is widely spread around the world with over 60 operational centres1 . In ten European and Asian centres, patients are irradiated with carbon ions. Nonetheless, the full potential of these therapies can only be realised by achieving a better understanding of physical, chemical and biological mechanisms, over a range of time and space scales, that leads to cell inactivation under ion radiation. The damaging effect of ionizing radiation has been known for many years. It has been commonly accepted that high-energy tracks formed by α, β, and γ radiation and atomic ions ionize cell components along the track, thereby leading to various dissociation channels and to the formation of damaging radicals. This has led to intensive research on the study of the mechanisms for the formation of such radicals and the fragmentation pattern of biomolecules by photons, electrons and ions. Such fundamental data underpins the study of radiation protec Contribution to the Topical Issue “COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy”, edited by Andrey V. Solov’yov, Nigel Mason, Gustavo Garcia and Eugene Surdutovich. a e-mail: 1 As of February 20162 . tion and the development of biomedical uses of different radiation, generally called radiotherapy, for treatment, of tumoural diseases in particular. The next generation of radiotherapy may be based on hadron therapy2 and in particular ion-beam therapy. To date the development of ion beam therapy has been based on empirical rather than phenomenological or ab initio scientific methods [4]. The emergence of the “RADAM” [4] and then “NanoIBCT”3 communities has played an important role in attracting physicists, chemists, and biologists into the field to tackle a plethora of scientific questions raised by the technological advances in this field. The majority of biological effects of ion beams are associated with the process of ionization of the medium by traversing ions. It is commonly accepted that secondary electrons, ejected by ionization, are mainly responsible for DNA damage, either breaking the DNA strands directly, or reacting with molecules of tissue, producing free radicals and other DNA reactive species. Macroscopically, the advantages of using ion beams compared to photons are related to the presence of a Bragg peak in the depth-dose distribution, where the production of secondary electrons is maximized. This localizes irradiation effects deep in tissue thus increasing the treatment efficiency and reducing side effects by sparing neighboring healthy tissue. However, the mechanisms involved in radiation damage on the 2 Particle therapy co-operative group, http://www.ptcog. ch/index.php/facilities-in-operation (accessed on 06/2014). 3 Cost action nano-IBCT, http://mbnresearch.com/ project-nanoibct (accessed on 02/2016). Page 2 of 4 nanoscale and molecular level are still a subject of fundamental multidisciplinary research. In 2010–2014, the European Concerted Research Action, COST Action MP1002: “Nano-scale insights in ion beam cancer therapy (Nano-IBCT)” was devoted to acquiring a deeper understanding of radiation induced damage with ions on the nanoscopic and molecular level. This endeavour clustered around the multiscale approach to the physics of radiation damage with ions [1,5], designed to achieve a quantitative understanding of the physical, chemical, and biological effects that take place on a wide range of spatial, temporal, and energy scales. The COST Action combined European experimental and theoretical expertise in several topics including nuclear reactions and electromagnetic processes during the propagation of ion beams in tissue, primary ionization in the medium (water and biological molecules), direct damage and production of secondary species (secondary electrons, radicals, holes), propagation of secondary species and their interaction with DNA, and radiobiological scale effects. Action was formally launched in December 2010 and since then has brought together more than 300 experts from different disciplines (physics, chemistry, biology, etc.) drawn from more than fifty different institutions including hadron therapy centres and medical institutions. The Action also engaged with colleagues working in countries outside the EU, including Canada, Australia, Japan, India, China and the USA. Two thirds of those participating were early career researches and a quarter were postgraduate students half of which were young female researchers. Within the framework of the COST Action Nano-IBCT three major conferences (held in Caen, France October 2011, Sopot, Poland May 2013 and Boppard, Germany 2013) and 12 workshops were organised. The Action also supported more than 100 Short Term Scientific missions between different institutions and countries, which resulted in more nearly 200 publications in high impact journals. For further details, see the Action’s website3 . The 3rd Nano-IBCT conference, held in Boppard, Germany, October 27–31, 2014, provided the opportunity to review recent progress in the field of radiation damage to biomolecular systems (...truncated)