Présents dans notre environnement les rayonnements électromagnétiques (EM) suscitent demultiples questions quant à leurs effets potentiels pour les porteurs de dispositifsmédicaux actifs implantés (DMAI). Le nombre croissant de porteurs d’implants médicaux, ycompris dans la population active, a entraîné un questionnement quant à leur comportementen présence d’un champ EM. L’interaction entre le corps humain et les champs EM restecomplexe et dépend de multiples facteurs tels que la fréquence, la puissance et lamodulation des champs. Nous présentons ici une revue de cette problématique dans le casdes champs EM basse fréquence.

The separate contributions of all source regions to organ doses from 131I and 123I administered to the bodywere calculated using voxelized reference phantoms. The photon and electron components oforgan doses were also evaluated for each source region. The MCNPX Monte Carlo particletransport code was utilized for dose calculations. All organs and tissues of male andfemale phantoms were taken into account as source regions with their correspondingcumulated activities. The results showed that cumulated activities assigned to sourceregions and inter-organ distances were two factors that strongly affected the contributionof each source to the organ dose. The major contribution of the dose to the main sourceregions arose from self-irradiation of electrons, while for nearby organs it was due tophotons emitted by the main source organs. In addition, self-irradiation plays animportant role in the dose delivered to most target organs for lower thyroid uptakes.

Interventional cardiologists (ICs) are repeatedly exposed to scattered ionising radiationduring the cardiac procedures they perform, and radiation protection is an important issuefor these medical professionals. The use of radiation protection tools is particularlyrelevant to this population. SISERI (Système d’Information de la Surveillance del’Exposition aux Rayonnement Ionisants, that is, an information system for monitoringexposure to ionising radiation) is a register that stores personal dosimeter readings fordosimetric monitoring. This paper, based on data for a sample of French ICs from theO’CLOC epidemiological study, aims to provide an overview of the use of radiationprotection equipment and dosimetric devices reported by ICs in a specific questionnaire aswell as the dosimetric information found in the SISERI database for this population.Material and Methods − Annual information on interventional cardiology activity for theperiod from 01/01/2005 to 31/12/2009 was collected in an occupational questionnaire. ICswere asked to report the frequency in which they used individual dosimeter and radiationprotection tools (lead apron, thyroid shield, eyewear or face shield, ceiling-suspendedshield) as follows: never (0% of the time), occasionally (<50%), regularly (>50%), always (100%). We retrieved theirmedical radiation exposure information (monitored status and monthly effective doses) fromthe SISERI database for the period 2005−2009. Results – Information for 132 ICs (mean age in2005 = 46 ± 7 years) wasavailable. All ICs reported routine use of lead aprons, in contrast to their occasionaluse of lead eyewear or face shields. During the study period, 49% reported systematic useof personal dosimeters, and 21% more regular use. On the other hand, 18% never used adosimeter during this period. The SISTERI database included 92% of our population, 73% ofwhom had complete annual dose monitoring in SISERI (corresponding to at least 11 monthsper year of recorded data). Conclusion − ICs must improve their regular use ofradiation protection tools and systematic use of personal dosimeters. The SISERI databaseis an appropriate tool for flagging those medical professionals exposed to ionisingradiation. Better awareness of the importance of radiation protection rules in thispopulation, in particular, systematic dosimeter use, remains an important issue.

The measurement performances of in vivo monitoring vehicles were studiedconsidering an increase in the radiological background in areas where the population isnot evacuated after a nuclear accident. The study focused on 137Cs and 131I Detection Limits (DLs) andcorresponding doses, for adults and one-year-old children. These DLs for groundcontamination were obtained experimentally using a grid of point sources. Then, the DLsand doses were calculated using the experimental data and a safety factor for two accidentscenarios. For these scenarios the 137Cs DL corresponds to a committed effective dose of0.02 mSv. The 131IDL corresponds to committed equivalent thyroid doses of 3 mSv (adult) and 30 mSv(one-year-old child). To guarantee a 45 mSv thyroid equivalent dose assessment for thechild the surface activity of 131I +132I +133I should be below 1.6 MBq/m2. This study shows that thevehicles can operate in a contaminated area where the population is not evacuated.However, in such a case, the contamination level outside and inside the vehicle should bekept stable to guarantee efficient body counting.

Classical beta spectra calculations are briefly described, highlighting the usualassumptions and limitations. To go beyond these usual assumptions, the numericalresolution of the Dirac equation for the atomic and beta electrons is necessary. Thisallowed us to determine the parameters λi involved in the theoretical shapefactors exactly. A systematic comparison between theoretical and experimental shapefactors led us to disqualify the usual λi = 1 assumption for all forbiddentransitions. The usual ξ-approximation was proved to be incorrect fornumerous first forbidden non-unique transitions, and for all higherorder non-uniquetransitions. A more accurate screening correction was defined and the atomic exchangeeffect was taken into account, an effect which is always neglected in usual calculations.The beta spectra of 63Ni and 241Pu, recently measured down to very low energies, arewell reproduced in our calculations. The exchange effect was demonstrated to have a greatinfluence on the spectral shape within this energy range.

For targeted radionuclide therapies, treatment planning usually consists of theadministration of standard activities without accounting for the patient-specific activitydistribution, pharmacokinetics and dosimetry to organs at risk. The OEDIPE software is auser-friendly interface which has an automation level suitable for performing personalizedMonte Carlo 3D dosimetry for diagnostic and therapeutic radionuclide administrations. Meanabsorbed doses to regions of interest (ROIs), isodose curves superimposed on apersonalized anatomical model of the patient and dose-volume histograms can be extractedfrom the absorbed dose 3D distribution. Moreover, to account for the differences inradiosensitivity between tumoral and healthy tissues, additional functionalities have beenimplemented to calculate the 3D distribution of the biologically effective dose (BED),mean BEDs to ROIs, isoBED curves and BED-volume histograms along with the EquivalentUniform Biologically Effective Dose (EUD) to ROIs. Finally, optimization tools areavailable for treatment planning optimization using either the absorbed dose or BEDdistributions. These tools enable one to calculate the maximal injectable activity whichmeets tolerance criteria to organs at risk for a chosen fractionation protocol. This paperdescribes the functionalities available in the latest version of the OEDIPE software toperform personalized Monte Carlo dosimetry and treatment planning optimization in targetedradionuclide therapies.

To go further in the optimization of treatment planning in selective internal radiationtherapy (SIRT), radiobiological aspects can be accounted for with the OEDIPE software andused to design fractionation protocols. Dosimetry was performed using data from99mTc-MAAevaluations of 10 patients treated for hepatic metastases with SIRT. The maximalinjectable activity (MIA) was calculated, using a tolerance criterion onBEDmean,healthyliver equal to 54 Gy2.5, for different fractionationprotocols, varying the number of fractions, the repartition of activity and the time delaybetween fractions. OEDIPE was also used to calculate BEDmean and the EUD to the tumoralliver (TL) that would be delivered with those MIAs. Compared with a single-injectionprotocol, the MIA is increased on average by 23% ± 3%, 36% ± 5% and 45% ± 7% for fractionation protocols with 2, 3and 4 equal fractions, respectively, while BEDmean,TL is increased by 15% ± 2%, 23% ± 4% and 29% ± 5%. EUDTL, calculated for oneevaluation, is increased by 51%, 115% and 159% using 2, 3 and 4 equal fractions,respectively. For this evaluation, the optimal activity repartition for two-fractionprotocols is (3/4 − 1/4) fortime delays of less than 4 days, (2/3 − 1/3) for time delays between 4 and 6 days and (1/2 − 1/2) for time delays superior to 6 days.Finally, this study confirmed that OEDIPE can be regarded as a tool for treatment planningoptimization and fractionation protocol design in SIRT.

Les traitements utilisant des rayons X de basse énergie continuent à être réalisés maisen faible nombre. Le praticien se trouve en général près du patient pour maintenirl’appareil et expose donc ses yeux. Avec la modification envisagée de la limite maximaled’exposition du cristallin, des mesures ont été jugées nécessaires pour mieux en connaîtrel’exposition. Pour cela une simulation des traitements a été réalisée. Pour la dose d’untraitement superficiel de 42 Gy, l’exposition du cristallin derrière des verres radioatténuateurs se situe entre 130 et 43 μSv pour des distances entre 40 et 60 cm. Pourl’intra cavitaire les valeurs obtenues sont vingt fois plus faibles. L’atténuation par lesverres est supérieure à 90 %. Le port des lunettes avec verres radio atténuateurs permetde minimiser la dose au cristallin de façon significative. L’application de la nouvellelimite maximale n’aura pas d’impact sur le nombre de traitements.