Dose assessment following an overexposure of a worker at a Swiss nuclear power plant.

Aim: The aim of this work was to assess the doses received by a diver exposed to a radiation source during maintenance work in the fuel transfer pool at a Swiss nuclear power plant, and to define whether the statutory limit was breached or not.

Method: Onsite measurements were carried out and different scenarios were simulated using the MicroShield Software and the MCNPX Monte Carlo radiation transport code to estimate the activity of the irradiating object as well as the doses to the limbs and the effective dose delivered to the operator.

Results: The activity of the object was estimated to 1.

EXPOSURE OF THE SWISS POPULATION BY RADIODIAGNOSTICS: 2013 REVIEW.

In 2013, a nationwide investigation was conducted in Switzerland to establish the population's exposure from medical X rays. A hybrid approach was used combining the Raddose database accessible on-line by the participating practices and the Swiss medical tariffication system for hospitals. This study revealed that the average annual number of examinations is 1.

Monte Carlo simulation of a whole-body counter using IGOR phantoms.

Whole-body counting is a technique of choice for assessing the intake of gamma-emitting radionuclides. An appropriate calibration is necessary, which is done either by experimental measurement or by Monte Carlo (MC) calculation. The aim of this work was to validate a MC model for calibrating whole-body counters (WBCs) by comparing the results of computations with measurements performed on an anthropomorphic phantom and to investigate the effect of a change in phantom's position on the WBC counting sensitivity.

Exposure of the Swiss population to computed tomography.

Background: The frequency of CT procedures has registered a significant increase over the last decade, which led at the international level to an increasing concern on the radiological risk associated with the use of CT especially in paediatrics. This work aimed at investigating the use of computed tomography in Switzerland, following the evolution of CT frequency and dose data over a decade and comparing it to data reported in other countries.

Methods: The frequency and dose data related to CT are obtained by means of a nationwide survey.

Swiss population exposure to radiation by interventional radiology in 2008.

The aim of this study was to investigate the radiation exposure of the Swiss population to interventional procedures. A nationwide survey was conducted in Switzerland. The annual effective dose per capita due to interventional procedures was found to be 0.

Exposure of the Swiss population by medical x-rays: 2008 review.

Nationwide surveys on radiation dose to the population from medical radiology are recommended in order to follow the trends in population exposure and ensure radiation protection.The last survey in Switzerland was conducted in 1998,and the annual effective dose from medical radiology was estimated to be 1 mSv y j(-1) per capita. The purpose of this work was to follow the trends in diagnostic radiology between 1998 and 2008 in Switzerland and determine the contribution of different modalities and types of examinations to the collective effective dose from medical x-rays.

Quality initiatives* radiation risk: what you should know to tell your patient.

The steady increase in the number of radiologic procedures being performed is undeniably having a beneficial impact on healthcare. However, it is also becoming common practice to quantify the health detriment from radiation exposure by calculating the number of cancer-related deaths inferred from the effective dose delivered to a given patient population. The inference of a certain number of expected deaths from the effective dose is to be discouraged, but it remains important as a means of raising professional awareness of the danger associated with ionizing radiation.

[Cardiac radiological investigations: what risks for the patients?].

The volume of diagnostic or therapeutic procedures in cardiology requiring the use of ionizing radiation is continuously increasing. While most examinations involve doses relatively low and thus add a low risk to the process itself, there are situations where the doses exceed the dose where excess risk of death from cancer has been statistically demonstrated. In addition, some complex procedures can result in the emergence of deterministic effects such as burns to the skin.

CT radiation dose in children: a survey to establish age-based diagnostic reference levels in Switzerland.

This work aimed at assessing the doses delivered in Switzerland to paediatric patients during computed tomography (CT) examinations of the brain, chest and abdomen, and at establishing diagnostic reference levels (DRLs) for various age groups. Forms were sent to the ten centres performing CT on children, addressing the demographics, the indication and the scanning parameters: number of series, kilovoltage, tube current, rotation time, reconstruction slice thickness and pitch, volume CT dose index (CTDI(vol)) and dose length product (DLP). Per age group, the proposed DRLs for brain, chest and abdomen are, respectively, in terms of CTDI(vol): 20, 30, 40, 60 mGy; 5, 8, 10, 12 mGy; 7, 9, 13, 16 mGy; and in terms of DLP: 270, 420, 560, 1,000 mGy cm; 110, 200, 220, 460 mGy cm; 130, 300, 380, 500 mGy cm.

CT dose optimization when changing to CT multi-detector row technology.

The purpose of this article was to review the strategies to control patient dose in adult and pediatric computed tomography (CT), taking into account the change of technology from single-detector row CT to multi-detector row CT. First the relationships between computed tomography dose index, dose length product, and effective dose in adult and pediatric CT are revised, along with the diagnostic reference level concept. Then the effect of image noise as a function of volume computed tomography dose index, reconstructed slice thickness, and the size of the patient are described.

Impact of the introduction of 16-row MDCT on image quality and patient dose: Phantom study and multi-centre survey.

The purpose was to compare the image quality and patient dose between 4- and 16-row MDCT units and to evaluate the dispersion of the dose delivered for common clinical examinations. Four 4- and 16-row MDCT units were used in the study. Image noise levels from images of a CatPhan phantom were compared for all units using a given CTDI(vol) of 15.

Optimisation in stereotactic radiosurgery of AVMs: II. Comparison of arc and MMLC therapy.

Two stereotactic surgery methods, arc and micro-multileave collimator (MMLC) therapy, were compared in the particular case of arteriovenous malformations (AVMs) treatment. Different methods of the treatment optimisation were used. The comparison covered a group of 22 patients suffering from peripheral and central AVMs of different sizes who underwent initially arc therapy.

Optimisation in stereotactic radiosurgery of AVMs: I. Mathematical considerations.

One forward-planning method and five inverse-planning methods for optimisation of treatment in radiation therapy were compared in the particular case of radiosurgery with micro-multi-leaves collimator (MMLC) and arc therapy. The "manual" method, two matrix methods (singular value decomposition and non-negative least square fit), two gradient methods (quasi-Newton and conjugate gradient algorithms) and the "simulated annealing" stochastic method were investigated. The performance of these methods was assessed in terms of the speed of convergence to an optimum, the ability to account for the organs at risk, and probability of targeted success.

Use of and irradiation from plain lumbar spine radiography in Switzerland.

Principles: Plain lumbar spine radiographic examination (LSRE) is frequently used in medical practice and delivers a high dose of ionising radiation. The objectives of the study were to determine the annual frequency of LSRE in Switzerland and its distribution according to practitioners' and patients' characteristics, as well as the related population dose of ionising radiation.

Methods: Data were extrapolated from a nationwide questionnaire survey on radiation exposure resulting from medical imaging in 1998, involving physicians and other healthcare providers performing radiological examinations in Switzerland.

Chiropractor's use of radiography in Switzerland.

Objective: In this article, we investigate the use of diagnostic radiology by chiropractors in Switzerland, with the aim of determining their contribution to the annual radiation collective dose.

Methods: We approached 138 chiropractors possessing radiologic equipment and asked them to provide, among other information, the frequency of radiographic examinations. The dose associated with each type of radiographic examination was established separately.