Response of current dosemeters to new operational quantities in rotational geometry.

Recently, the ICRU released Report 95, where new operational quantities for external radiation exposure are defined. The new quantities are defined in close relation to the protection quantities. This change affects the practice use of dosemeters.

RESPONSE OF CURRENT AREA DOSEMETERS TO NEW OPERATIONAL QUANTITIES.

New operational quantities for external radiation exposure presented by the ICRU brought changes, which can affect the use of current dosemeters. Dosemeters calibrated in the old quantities should be tested, and the results obtained should be analyzed with respect to the new quantities. The difference between the old and new quantities depends primarily on photon energy.

Comparison of luminescence detectors of AlO:C, CaF:Mn, LiF:Mg,Cu,P and quartz with respect to retrospective dose reconstructions using bricks.

In the aftermath of an orphan radiation source find, a complex retrospective dose reconstruction can be required to estimate doses of persons who were staying in the vicinity. In retrospective dose reconstructions based on luminescence measurements of quartz extracted from bricks, high sensitivity thermoluminescence detectors (TLD) can be used as an ancillary tool for dose distribution measurements or natural radiation background measurement. We investigated the potential and limits of AlO:C, CaF:Mn and LiF:Mg,Cu,P detectors for such applications.

RETROSPECTIVE DOSE RECONSTRUCTION WITH MOBILE PHONES AND CHIP CARDS.

Mobile phones and common chip cards are very widespread items that almost everyone owns. They contain some radiation-sensitive materials that can be used for dosimetry based on stimulated luminescence. We investigated and compared reproducibility, dose response and fading of luminescence signal for the particular materials.

ASSESSMENT OF EYE LENS DOSES IN INTERVENTIONAL RADIOLOGY: A SIMULATION IN LABORATORY CONDITIONS.

As workers in interventional radiology belong to one of the most occupationally exposed groups, methods for sufficiently accurate quantification of their external exposure are sought. The objective of the authors' experiment was to investigate the relations between eye lens dose and Hp(10), Hp(3) or Hp(0.07) values measured with a conventional whole-body personal thermoluminescence dosemeter (TLD).

Retrospective dosimetry with alumina substrate from electronic components.

Alumina substrate can be found in electronic components used in portable electronic devices. The material is radiation sensitive and can be applied in dosimetry using thermally or optically stimulated luminescence. Electronic portable devices such as mobile phones, USB flash discs, mp3 players, etc.

NaCl as a retrospective and accident dosemeter.

NaCl is a cheap and widely available material. This study investigated the potential of NaCl in the form of a household salt as a retrospective and accident dosemeter using optically stimulated luminescence (OSL). Samples of the investigated household salt were stimulated using blue light of linearly modulated power.

Lethal events in V79 cells irradiated by low-energy protons and correlations with distribution patterns of energy deposition, radical concentration and DNA damage.

Published survival data of V79 cells irradiated by 0.5-5.0 MeV (7-40 keV/microm) protons have been analyzed with a detailed radiobiological model to estimate the per-track yields of lethal lesions.

Concurrent versus sequential chemoradiotherapy with cisplatin and vinorelbine in locally advanced non-small cell lung cancer: a randomized study.

Purpose: The superiority of chemoradiotherapy (CRT) over radiation alone in locally advanced non-small cell lung cancer (NSCLC) has been proven, but the relative merits of a concurrent schedule versus their sequential administration are less clear. This study compared the safety and efficacy of concurrent and sequential CRT, with chemotherapy (CT) consisting of a cisplatin and vinorelbine regimen, in patients with locally advanced NSCLC.

Patients And Methods: One hundred and two previously untreated patients (aged 42-75 years) with locally advanced, stage IIIA (n = 15) or stage IIIB (n = 87) NSCLC were entered into the study.

Thermoluminescent dosimeters (TLD) quality assurance network in the Czech Republic.

Introduction: The Czech thermoluminescent dosimeters (TLD) quality assurance network was established in 1997. Its aim is to pursue a regular independent quality audit in Czech radiotherapy centres and to support state supervision.

Materials And Methods: The audit is realised via mailed TL dosimetry.

Inactivation of individual cells by divers ions at different LET values.

A new formula linking the shape of survival curve to the inactivation probabilities after different numbers of cell hits has been derived. It has been used in analyzing recent experimental data obtained with monolayer cells irradiated at definite values of LET (in different parts of Bragg peaks). The new approach allows not only deriving the values of inactivation probabilities at given LET values; unexpected consequences seem to follow especially for inactivation characteristics of carbon ions in different parts of the Bragg peak, too.

Cell inactivation by ionizing particles and the shapes of survival curves.

Recent experiments concerning the survival of monolayer cells irradiated by different parts of ion Bragg peaks opened a way to a deeper mechanistic understanding of cell inactivation. A new theoretical formula for survival curves has been derived reflecting two basic phases of the given mechanism, i.e.

Progression rate of radiation damage to the mouse kidney: a quantitative analysis of experimental data using a simple mathematical model of the nephron.

Mouse kidneys were irradiated bilaterally with a range of single or fractionated X-ray doses. After an interval of 2 weeks or 26 weeks, the animals were reirradiated with a range of single X-ray doses. The rate of development of functional kidney damage was assessed repeatedly by the 51Cr-EDTA clearance assay.

Perspectives of tumour radiotherapy in the Czech Republic and "Oncology 2000" Foundation.

The incidence of tumours has still an increasing tendency. A great effort is being devoted to prevention as well as to improving early diagnosis and treatment. It is the radiotherapy which seems to bring new treatment possibilities at the present.

Proliferative response of mouse spermatogonial stem cells after irradiation: a quantitative model analysis of experimental data.

The testes of CDF1 mice were irradiated with single doses of X-rays ranging from 2-16 Gy. The number of haploid cells in the testis at different times after irradiation (42-350 days) was determined by one-parameter flow cytometry both for irradiated animals and for age-matched controls. Based on literature data on the kinetics of the spermatogenesis in mice, a mathematical model of the (hierarchical) germ tissue was developed.

Time evolution of the number of functional murine eccrine sweat glands after irradiation: a quantitative analysis of experimental data using a model of proliferative and functional organization.

The function of eccrine sweat glands in the beta-pad of the mouse foot after irradiation was followed over time. Graded doses of X-rays were given to the foot, either as single doses or in two equal fractions separated by a 24-h interval. A quantitative, non-invasive, functional assay was used allowing repeated evaluation of the animals.

Application of a semi-phenomenological model to experimental data of radiation induced pneumopathy in pigs.

A semi-phenomenological model has been derived, which describes the inactivation effect on individual cells by survival curves. This model is applied to experimental data of pneumopathy in pigs. The corresponding survival curves as well as the relations between cell survival and complication probability are calculated and discussed.

Mathematical models of cumulative effect and optimization of fractionation regimes.

Different (most known) mathematical models are shortly described and basic assumptions the individual models are based on are discussed and critically examined. Advantages and shortages of individual models are mentioned. A semiphenomenological model is then used to demonstrate some possibilities how to make use of the mathematical models in attempts of optimizing the fractionation approaches in individual cases.