Fyzikální ústav Akademie věd ČR

Particle physics in medicine

Members of this group focus their research interests on potential applications of particle physics in medicine, in particular in the treatment of cancer. Hadron radiotherapy, i.e., treatment of cancer with the help of irradiating tumours with proton and light ion beams, is a modern treatment modality which allows to spare surrounding healthy tissues and limit the radiation-induced burden to the whole organism. The method is expected to significantly improve the cure rate of cancer in the near future. Our research activities are focused mainly on mathematical modelling of processes running in irradiated cells and leading finally to killing of tumour cells and tumour eradication, or which occur in irradiated healthy cells and lead to negative side-effects of the treatment. Mathematical modelling of these processes is essential for optimal treatment planning in the radiotherapy of cancer. These models also help to better understand the characteristics and mechanisms of biological effects of ionizing radiation, which have been determined within experimental radiobiological research.

The probabilistic two-stage model of the cell killing effects of ionizing radiation, proposed by us [1], makes it possible to mathematically represent the induction of damage by radiation as well as its repair by the cell. A systematic analysis of cell killing data after irradiations with proton and light ion beams has been performed to quantify the amount and severity of the induced damage in dependence of the radiation quality [2]. These results have been complemented by an analytical model of the characteristic energy deposition profile by ion beams, so-called Bragg peak, and used in developing a fast semi-analytical model of biological effects of proton and ion beams that can assist treatment planning in hadron radiotherapy [3]. In addition, in cooperation with the Nuclear Physics Institute of AS CR, the biophysical interpretation of the radiation-induced damage to cells has been addressed. Correlations have been found between the radiation-quality dependent damage induction probabilities and the profiles of energy deposition, yields and distributions of radical species, and yields of specific molecular lesions to cellular DNA [5].

At present, our research activities are aimed primarily at modelling the differences in responses to radiation between normal cells and their radiosensitive mutants. The goal of these studies is to derive detailed characteristics of repair processes in cells, i.e. of cellular abilities to repair radiation-induced DNA damage.

The group is actively involved in the European multidisciplinary platform ENLIGHT (The European Network for LIGht ion Hadron Therapy, http://cern.ch/enlight), which aims at a coordinated effort towards ion beam research and broad and efficient applications of hadrontherapy in Europe. The group members also contribute to the project Cooperation of the Czech Republic with CERN, and have contributed to the national grant project “Modelling of radiobiological mechanism of protons and light ions in cells and tissues” (2005-2007, GA202/05/2728, http://www.isvav.cz/projectDetail.do?rowId=GA202%2F05%2F2728).

Important publications:
  1. Kundrát P., Lokajíček M., Hromčíková H.: Probabilistic two-stage model of cell inactivation by ionizing particles. Physics in Medicine and Biology 50 (7), 1433-1447, 2005
  2. Kundrát P.: Detailed analysis of the cell-inactivation mechanism by accelerated protons and light ions. Physics in Medicine and Biology, 51 (5), 1185-1199, 2006
  3. Kundrát P.: A semi-analytical radiobiological model may assist treatment planning in light ion radiotherapy. Physics in Medicine and Biology 52 (23), 6813-6830, 2007
  4. Hromčíková H.: Modelling of radiobiological mechanisms in cells and tissues, disertační práce, Praha 2008
  5. Davídková M., Kundrát P., Štěpán V., Palajová Z., Judas L.: Lethal events in V79 cells irradiated by low-energy protons and correlations with distribution patterns of energy deposition, radical concentration and DNA damage. Applied Radiation and Isotopes 67 (3), 454-459, 2009

Researchers:
Pavel Kundrát, Miloš Lokajíček Sn., Hana Pisaková (Hromčíková)

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