Exposure of the eye lens and brain for interventional cardiology staff.

Introduction: Occupational exposure to ionizing radiation for people working with an X-ray treatment unit is one of the highest in medicine. The epidemiological data analyzed by the International Commission on Radiological Protection (ICRP) indicate that the dose threshold for tissues located in the eye lens is or may be lower than previously thought. The new ICRP recommendations reduce the currently used threshold 7.

Lead shielding efficiency from the gamma background measurements in the salt cavern of the Polkowice-Sieroszowice copper mine.

The studies of lead shielding efficiency from the gamma background measurements were performed in the salt cavern of the copper mine - a site considered for an underground laboratory. Within the energy range of 50-2700 keV, the measured gamma-ray count rates normalized to the mass of the high-purity detectors germanium crystal are 5.93 and 6.

Assessment of radiation exposure outside the radiotherapeutic room during medical accelerator beam emission with the use of TL detectors (radiation exposure outside a LINAC room).

Photon and neutron soft tissue absorbed doses near the entrance door to the medical LINAC treatment room were measured with the use of thermoluminescent detectors LiF:Mg,Cu,P in the anthropomorphic phantom. Two different therapeutic beams (6 and 15 MV) and four treatment techniques were involved in the present study. This allowed one to investigate the contribution of scattered X rays, secondary neutrons and gamma rays to the radiation field.

Nuclear reactions in linear medical accelerators and their exposure consequences.

Qualitative and quantitative analysis of radionuclides originating inside a medical linear accelerator during emission of high-energy therapeutic photon beams (15, 18, and 20 MV) is presented. The semiconductor spectrometry method allowed to obtain the fluence rate of photons with defined energy and hence, to quantify the dose at the chosen points in the vicinity of linac, contribution of particular radionuclides and its evolution in time. Typically used materials: copper, tungsten, lead, tantalum and their admixtures: antimony, manganese or bromine, are activated the most.

Correlation between radioactivity induced inside the treatment room and the undesirable thermal/resonance neutron radiation produced by linac.

High-energy therapeutic beams used in the radiotherapy induce photonuclear and electronuclear reactions which are accompanied by generation of undesirable radioisotopes and neutrons inside the treatment room. These neutrons at thermal and resonance energies induce nuclear reactions through the whole accelerator bunker. In consequence various radioisotopes emitting high-energy photons appear.

Undesirable nuclear reactions and induced radioactivity as a result of the use of the high-energy therapeutic beams generated by medical linacs.

In this paper, the problem of undesirable photonuclear, electronuclear and neutron capture reactions taking place in the treatment room during emission of the typical high-energy therapeutic beams from two different medical accelerators, i.e. Primus Siemens and Varian Clinac-2300, is presented.