Joint EURADOS-EANM initiative for an advanced computational framework for the assessment of external dose rates from nuclear medicine patients.

Background: In order to ensure adequate radiation protection of critical groups such as staff, caregivers and the general public coming into proximity of nuclear medicine (NM) patients, it is necessary to consider the impact of the radiation emitted by the patients during their stay at the hospital or after leaving the hospital. Current risk assessments are based on ambient dose rate measurements in a single position at a specified distance from the patient and carried out at several time points after administration of the radiopharmaceutical to estimate the whole-body retention. The limitations of such an approach are addressed in this study by developing and validating a more advanced computational dosimetry approach using Monte Carlo (MC) simulations in combination with flexible and realistic computational phantoms and time activity distribution curves from reference biokinetic models.

A puzzling case of contamination with Am.

Two people were exposed to and contaminated with Am. In vivo determinations of the incorporated Am were performed using a whole-body counter and two partial-body counters for the skull and lung, respectively. Additionally, urine samples were analysed to estimate the systemic activity removed from the body.

Concerted Uranium Research in Europe (CURE): toward a collaborative project integrating dosimetry, epidemiology and radiobiology to study the effects of occupational uranium exposure.

The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear.

The NUKDOS software for treatment planning in molecular radiotherapy.

The aim of this work was the development of a software tool for treatment planning prior to molecular radiotherapy, which comprises all functionality to objectively determine the activity to administer and the pertaining absorbed doses (including the corresponding error) based on a series of gamma camera images and one SPECT/CT or probe data. NUKDOS was developed in MATLAB. The workflow is based on the MIRD formalism For determination of the tissue or organ pharmacokinetics, gamma camera images as well as probe, urine, serum and blood activity data can be processed.

Metrics, dose, and dose concept: the need for a proper dose concept in the risk assessment of nanoparticles.

In order to calculate the dose for nanoparticles (NP), (i) relevant information about the dose metrics and (ii) a proper dose concept are crucial. Since the appropriate metrics for NP toxicity are yet to be elaborated, a general dose calculation model for nanomaterials is not available. Here we propose how to develop a dose assessment model for NP in analogy to the radiation protection dose calculation, introducing the so-called "deposited and the equivalent dose".

Ninth Annual Warren K. Sinclair Keynote Address: effects of childhood radiation exposure: an issue from computed tomography scans to Fukushima.

The acute and chronic effects of radiation on children have been and will continue to be of great social, public health, scientific, and clinical importance. The focus of interest on ionizing radiation and children has been clear for over half a century and ranges from the effects of fallout from nuclear weapons testing to exposures from accidents, natural radiation, and medical procedures. There is a loosely stated notion that "children are three to five times more sensitive to radiation than adults.

Radiation risk and protection of patients in clinical SPECT/CT.

Clinical studies have demonstrated that hybrid single photon emission computed tomography (SPECT)/CT for various diagnostic issues has an added value as compared to SPECT alone. However, the combined acquisition of functional and anatomical images can substantially increase radiation exposure to patients, in particular when using a hybrid system with diagnostic CT capabilities. It is, therefore, essential to carefully balance the diagnostic needs and radiation protection requirements.

Dosimetry of 223Ra-chloride: dose to normal organs and tissues.

Purpose: (223)Ra-Chloride (also called Alpharadin®) targets bone metastases with short range alpha particles. In recent years several clinical trials have been carried out showing, in particular, the safety and efficacy of palliation of painful bone metastases in patients with castration-resistant prostate cancer using (223)Ra-chloride. The purpose of this work was to provide a comprehensive dosimetric calculation of organ doses after intravenous administration of (223)Ra-chloride according to the present International Commission on Radiological Protection (ICRP) model for radium.

Biokinetics and dosimetry of commonly used radiopharmaceuticals in diagnostic nuclear medicine - a review.

Purpose: The impact on patients' health of radiopharmaceuticals in nuclear medicine diagnostics has not until now been evaluated systematically in a European context. Therefore, as part of the EU-funded Project PEDDOSE.NET ( www.

Radiation protection for pregnant workers and their offspring: a recommended approach for monitoring.

Radiation protection of pregnant workers and their offspring is an issue that has been referenced in the literature by the International Commission on Radiological Protection (ICRP), the International Atomic Energy Agency (IAEA) and other international institutions. Several documents of the ICRP address the issue of the protection of the pregnant workers. The new ICRP recommendations refer to the control of working conditions of a pregnant worker, after declaration of pregnancy, such that it is unlikely that the additional dose to the fetus will exceed about 1 mSv during the remainder of pregnancy.

The CONRAD approach to biokinetic modeling of DTPA decorporation therapy.

Diethylene Triamine Pentaacetic Acid (DTPA) is used for decorporation of plutonium because it is known to be able to enhance its urinary excretion for several days after treatment by forming stable Pu-DTPA complexes. The decorporation prevents accumulation in organs and results in a dosimetric benefit, which is difficult to quantify from bioassay data using existing models. The development of a biokinetic model describing the mechanisms of actinide decorporation by administration of DTPA was initiated as a task in the European COordinated Network on RAdiation Dosimetry (CONRAD).

Risks and safety aspects related to PET/MR examinations.

Introduction: The introduction of positron emission tomography (PET)/magnetic resonance (MR) systems into medical practice in the foreseeable future may not only lead to a gain in clinical diagnosis compared to PET/computed tomography (CT) imaging due to the superior soft-tissue contrast of the MR technology but can also substantially reduce exposure of patients to ionizing radiation. On the other hand, there are also risks and health effects associated with the use of diagnostic MR devices that have to be considered carefully.

Objectives: This review article summarizes biophysical and biological aspects, which are of relevance for the assessment of health effects related to the exposure of patients to both ionizing radiation in PET and magnetic and electromagnetic fields in MR.

Estimation of patient dose from radiopharmaceuticals using voxel models.

The aim of this study was to demonstrate the advantages of patient dosimetry using voxel models and to present sets of dose estimates for patients of different gender and size. These models offer greater realism with respect to organ shape and topology than the well-established Medical Internal Radiation Dose (MIRD)-type mathematical models. At the National Research Centre for Environment and Health (GSF), specific absorbed fractions have been previously calculated for 4 male and 3 female voxel models, representing different age and stature, for a wide range of source organs.

[Acquisition and assessment of patient exposure in diagnostic radiology and nuclear medicine].

The regular annual monitoring of patient exposure in radiation diagnostics, as performed by the Federal Office for Radiation Protection (BfS), plays an important role in evaluating the awareness of radiological quality and safety in Germany and the risk-benefit optimization for patients. For the reporting year 1997, X-ray diagnostics resulted in a mean effective dose of 2 +/- 0.5 mSv per head of population.

Therapy of ankylosing spondylitis with 224Ra-radium chloride: dosimetry and risk considerations.

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease which reduces the quality of life and leads to disability in approximately one-third of the patients. The spectrum of therapeutic modalities is limited. The renaissance of the use of (224)Ra-radium chloride for AS treatment, however, gives rise to concern which should result in the reconsideration of (224)Ra dosimetry and in the discussion of the risks associated with this treatment.

A survey of PET activity in Germany during 1999.

Positron emission tomography (PET) is the most powerful molecular imaging technique currently available for clinical use. The aim of this study was to provide public health information on PET procedures carried out in Germany - a country with a very high number of PET installations. To this end, all facilities that in 1999 were running at least one dedicated PET system were contacted and requested to provide information in a questionnaire on the radiopharmaceuticals applied, the total number and age distribution of patients and volunteers examined, the main diagnostic applications and the range of administered activities.