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Low-Dose Radiation Therapy

#3291


Investigation of the Biological Effects of the Pulse-Periodic X-ray Radiation of the Nanosecond Pulse Duration with the Purpose of Developing New Approaches in the Low-Dose Radiation Therapy

Tech Area / Field

  • BIO-RAD/Radiobiology/Biotechnology
  • MED-RAD/Radiomedicine/Medicine
  • BIO-CGM/Cytology, Genetics and Molecular Biology/Biotechnology

Status
3 Approved without Funding

Registration date
03.06.2005

Leading Institute
Cancer Research Institute, Siberian Branch, Russian Academy of Medical Sciences, Russia, Tomsk reg., Tomsk

Supporting institutes

  • Siberian Branch of RAS / Institute of High Current Electronics, Russia, Tomsk reg., Tomsk

Collaborators

  • Toyama University / Faculty of Medicine, Japan, Toyama\nUniversity of Kyoto/ Kinski Invention Center, Japan, Kyoto

Project summary

While there have been many studies on the biological and medical effects of continuous X-ray radiation, there is much less information on the effects of pulse-periodic X-ray exposure, especially at nanosecond pulses into the train with low sum absorbed dose. Authors of the project are working with the repetitive X-ray source of nanosecond pulses on base of the high current electron accelerator of gigawatt beam pulse power at 300 kV level of peaking voltage. The special type of explosive-emission cathode with long lifetime (about 108 pulses) is used. All ideas and the concept of the compact electron accelerator (length is about 1 meter) were developed at HCEI.

Our preliminary experiments have shown that a low-dose X-ray radiation in the pulse-periodic mode at the certain repetition rates can lead to almost 100% inhibiting the growth of tumor cells of the P-815 mastocytoma at the absorbed dose less than 0.1 Gy. It was expected result because earlier we had been observed strong effects of pulse-periodic X-ray radiation on the developing organism of Drosophila when the interruption of development at larvae stage was reached about 90%. Pulse repetition rates were 13 and 16 Hz. Thus, the role of pulse repetition rate is the key one. Now we can suppose that damages are being increased or relaxed in the range of some frequencies due to the own intracellular dynamic processes with corresponding specific times. Among them, the oxidated enzymes reduction, the membranes potential recovery, the intracellular variation of Ca2+ or other signal transduction pathways and combinations can take place.

The main purpose of the project is to investigate the effects of pulse-periodic X-ray irradiation on tumor and normal cells in vitro and in vivo and determine the possible mechanisms of the anti-tumor radiation effect.

The project is a complex investigation including carrying out experiments and biological tests, analyzing the obtained results and developing technologies for application in medical practice. Scientists of various fields of knowledge will be engaged in the project. The investigation tasks include the designing and manufacture of the second X-ray source for the location in the Cancer Research Institute; improvement of the method of control of the absorbed dose near objects in the course of irradiation; mastering and improving ancillary methods of control of the biological effects; detection of optimum parameters of the pulse-periodic X-ray radiation (pulse-repetition rate, radiation dose) to achieve the maximum anti-tumor effect in vitro and in vivo and detecting of normal cells response as well as the mechanisms responsible for inhibition of cell proliferation.


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