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A novel approach for rapid 89, 90Sr determination in seawater samples is developed. For the first time in the radioanalytical application, the features of the synthetic zeolite Z4A and a highly selective material for Sr separation were synergically employed. Seawater composition significantly reduces Sr yield on highly selective solid-phase extraction materials, making the preconcentration step essentially important but laborious and timeconsuming. To address this issue, the ability of zeolite 4A to concentrate the Sr from the seawater matrix was employed. With the proposed method, two important goals were achieved: (i) simple preconcentration of Sr that can be conducted directly at the sampling site, enabling a rapid procedure for 89, 90Sr determination in emergencies, and (ii) high and stable Sr recoveries (89 ± 4%) necessary for lowering detection limits. Strontium is effectively separated from 1 L of seawater in less than 1.5 h, which is especially important in emergency situations, such as the Fukushima Daiichi Nuclear Power Plant accident. Minimum detectable activities achieved for 89Sr:90Sr activity ratio ~10:1 were 0.74 Bq/L for 89Sr, and 1.47 Bq/L for 90Sr, detected by Cherenkov counting, 36–38 h after separation, and 30 min counting time.

In this study we analyzed the dose response of natLiF:Mg,Cu,P (MCP-N) detectors in two different TLD readers (Harshaw 5500 and Toledo 654 Vinten) at 7 dose levels, ranging from 0.5 mGy to 5 Gy, for different heating rates (2 °C/s, 5 °C/s, 10 °C/s and 15 °C/s) and using 2 protocols: one without pre-heating and a maximum reading temperature of 255 °C and one including external pre-heating before the readout for 20 min at 100 °C and maximum temperature of 230 °C. The results show a supralinear behavior for Harshaw 5500 reader at high doses which is more pronounced for the fast heating rates. For the 15 °C/s heating rate, the supralinearity starts at 2 Gy for the protocol without pre-heating and at 0.5 Gy for the protocol with pre-heating reaching up to linearity indices of respectively 1.42 ± 0.05 and 1.67 ± 0.05 at 5 Gy. The 2 °C/s heating rate does not show supralinearity up till 5 Gy. The Toledo 654 Vinten reader shows no supralinear behavior. The shape of the glow curves is different between readers and reading protocols while the glow curve peaks shift towards higher temperatures for increasing heating rates due to thermal lag effects. This study demonstrates the different behaviors of TLD readers, for different heating rates and two types of protocols with an important concern for a Harshaw reader.

When a radiological and nuclear (R/N) emergency occurs, the categorization of individuals into those who are unaffected and those requiring medical intervention is a high priority. At times, a professional dosimeter is not available and therefore some common belongings may be used as fortuitous dosimeters. The preparation of these objects for the measurement should be such as to give the most accurate and precise results. This paper focused on the Photo-Stimulated Luminescence (PSL) response of salty crackers confronts the problem of sample preparation (mass, grain size), dose response and signal stability. The dose response was determined for doses up to 5 Gy, which allowed the calculation of the limit of detection. Additionally, the signal stability was investigated for samples irradiated with 0.3 and 3 Gy. The observed decrease of the signal does not prevent the detection in the dose range typical for R/N emergency. The main dosimetric characteristics were investigated by using two different models of PSL readers equipped with single (infrared) or double (infrared, blue light) stimulation. The results indicated that the limit of detection can be improved by applying blue light stimulation. Moreover, strong correlation of the measurements performed in the two different instruments, as well as the rapidity of the analysis and the simplicity of the operations, suggest that this method can be suitable for a rapid radiation triage of a large number of civilians in a mass casualty event. The study was simultaneously conducted by two laboratories (Ruder Bošković Institute, RBI, Croatia and Istituto Superiore di Sanità, ISS, Italy) involved in the BioPhyMeTRE project (grant No. G5684) supported by NATO Science for Peace and Security Programme.

The 14C method can be successfully applied for determination of biogenic component in any type of samples and different measurement techniques can be applied. For a special case of liquid fuels, direct method by measurement 14C activity of liquid fuel samples in liquid scintillation counter (the „direct LSC method“) has been recognized as a powerful and reliable method of determination of biogenic component (fbio). In the Ruđer Bošković Institute (RBI) Radiocarbon Laboratory we have been implemented our own data evaluation method based on the quench properties of fuels (SQP(E) – Standard Quench Parameter in LSC Quantulus 1220) [1]. We participated in the international intercomparison study ILC/2018 Content of biocomponent in liquid fuel samples, which was organized in 2018 by the Institute of Ceramics and Building Materials (Opole, Poland). Here we compare our fbio results with the fbio-ILC official results and report optimization of the direct LSC method. Laboratories obtained seven samples of diesel type of fuel having different colors. Consequently, the samples resulted in different SQP(E) values when the direct LSC methods was applied. Three samples were analyzed by the AMS (Accelerator Mass Spectrometry) method. The LSC results were quantitatively acceptable for four samples with SQP(E) values above 700 (Figure 1), which was taken as the lowest limit of quantitative fbio determination. Qualitatively acceptable, but quantitatively unacceptable results, were obtained for two samples with the SQP(E) values between 600 and 700, that was defined as the region of limited applicability. For one of the samples the quenching was high, SQP(E) < 600, and the direct LSC method did not give any result. However, all AMS results were acceptable (Figure 1) since AMS does not depend on the sample color. The obtained results have been used for further validation and optimization of the direct LSC method. We defined the limits of applicability of the direct-LSC method for both quantitative (SQP(E) > 700) and qualitative results (600 < SQP(E) < 700). A sample of used edible oil (UEO, laboratory code Z-7226) was used to test these limits. The UEO was a dark sample giving the SQP(E) value of 546 (below the limit of qualitative applicability), while the AMS revealed fbio = 97.9 ± 0.3 % (and δ13C = -29.6 ‰). We mixed the UEO with the (fossil) petrol (benzene) sample (laboratory code Z-6266), which we used as the background sample (fbio = 0 %) with good quenching properties (SQP(E) = 864). We monitored changes in the SQP(E) and fbio values in UEO-petrol mixtures in the concentration range 0 – 100 %. The total mixture volume was 10 mL and 10 mL of Ultima Gold F scintillation cocktail was added, i.e., the measurement was performed in the same manner as all other organic liquid samples [1]. Mixtures of 10 % and 20 % of UEO gave SQP(E) values of 773 and 759, and the fbio was calculated to be 104.0 ± 1.2 % and 101.1 ± 1.3 %, respectively, confirming the quantitative region of SQP(E) values above 700. Mixtures containing 30 – 50 % of UEO resulted in SQP(E) values between 671 and 609, while the fbio values were about 150 %, confirming qualitatively acceptable results. Mixtures containing more than 60 % of UEO had SQP values below 600 and fbio values had a large spread. The presented results showed that the direct LSC method with an evaluation method developed in our laboratory was suitable for determination of the fbio in liquid fuels, providing the correctly defined limits of applicability for highly quenched samples. The RBI Laboratory has a possibility of applying also AMS 14C measurement technique that can satisfactorily determine fbio also in highly quenched samples, but the AMS technique is more complicated and more expensive.

A rapid, automated separation procedure was developed for radioactive strontium and lead isotope determination. This system includes a portable automated system for the preconcentration and sequential elution of targeting isotopes with an Na2H2EDTA solution from solid phase extraction materials, AnaLig®Sr-01 and SuperLig®620, provided by IBC Technologies. Strontium and lead were separated from the majority of matrix constituents to obtain pure fractions of Pb and Sr prior to radiometric detection. In case of barium presence, it can also be fully isolated and completely separated from Sr. The automated procedure can be successfully used for preconcentration and separation from high as well as low radioactivity samples. With only a 1 mL column filled with SuperLig®620, it is possible to isolate Sr and Pb with 100% recovery from 1 L to 2 L of sample at a flow rate of up to 10 mL min−1 within several hours. 89,90Sr isotopes can be further determined by Cherenkov counting, while 210Pb isotopes can be determined by either gamma spectrometry or liquid scintillation counter. The method was tested and validated using certified standard materials and proficiency test samples. The synergy of automated separation and detection procedures enables the determination of the low level activity of 90Sr and 210Pb in a short time with detection limits of 20 mBq L−1 for both isotopes. The proposed method enables lower labour costs, minimal size of apparatuses and columns, low separation time, and reduced secondary waste production. The automated procedure may be easily implemented in laboratories worldwide and can also be used at sampling sites.

Our current understanding of the importance of surface-active substances (SAS) on atmospheric aerosol cloud-forming efficiency is limited, as explicit data on the content of size-resolved ambient aerosol SAS, which are responsible for lowering the surface tension (σ) of activating droplets, are not available. We report on the first data comprising seasonal variability of size-segregated SAS concentrations in ambient aerosol particulate matter (PM). To assess the impact of SAS distribution within PM on cloud droplet activation and growth, a concept of surfactant activity was adopted and a parametrization developed ; i.e., surfactant activity factor (SAF) was defined, which allowed translation of experimental data for use in cloud parcel modeling. The results show that SAS-induced σ depression during cloud activation may affect droplet number ( Nd) as much as a 2-fold increase in particle number, whereas by considering also the size distribution of particulate SAS, Nd may increase for another 10%. This study underscores the importance of size-resolved SAS perspective on cloud activation, as data typically obtained from aqueous extracts of PM2.5 and PM10 may result in misleading conclusions about droplet growth due to large mass fractions of supermicron particles with SAS deficit and little or no influence on CCN and Nd.

The purpose of this study was to measure out-of-field organ doses in two anthropomorphic child phantoms for the treatment of large brain arteriovenous malformations (AVMs) using hypofractionated gamma knife (GK) radiosurgery and to compare these with an alternative treatment using intensity-modulated radiation therapy (IMRT). Target volume was identical in size and shape in all cases. Radiophotoluminescent (RPL), thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters were used for out-of-field dosimetry during GK treatment and a good agreement within 1-2% between results was shown. In addition, the use of multiple dosimetry systems strengthens the reliability of the findings. The number of GK isocentres was confirmed to be important for the magnitude of out-of-field doses. Measured GK doses for the same distance from the target, when expressed per target dose and isocentre, were comparable in both phantoms. GK out-of-field doses averaged for both phantoms were evaluated to be 120 mGy/Gy for eyes then sharply reduced to 20 mGy/Gy for mandible and slowly reduced up to 0.8 mGy/Gy for testes. Taking into account the fractionation regimen used to treat AVM patients, the total treatment organ doses to the out-of-field organs were calculated and compared with IMRT. The eyes were better spared with GK whilst for more distant organs doses were up to a factor of 2.8 and 4 times larger for GK compared to IMRT in 5-year and 10-year old phantoms, respectively. Presented out-of-field dose values are specific for the investigated AVM case, phantoms and treatment plans used for GK and IMRT, but provide useful information about out-of-field dose levels and emphasise their importance.

The purpose of this study was to measure out-of-field organ doses in clinical conditions in anthropomorphic paediatric phantoms which received a simulated treatment of a brain tumour with intensity modulated radiotherapy (IMRT) and 3D conformal radiotherapy (3D CRT). Organ doses measured with radiophotoluminescent and thermoluminescent dosemeters were on average 1.6 and 3.0 times higher for the 5 year-old than for the 10 year-old phantom for IMRT and 3D CRT, respectively. A larger 5-year to 10-year organ dose ratio for 3D CRT can be explained because the use of a mechanical wedge for the 5 year-old 3D CRT phantom treatment increased out-of-field doses. Due to different configurations of the radiation fields, for both phantoms, the IMRT technique resulted in a higher non-target brain dose and higher eye doses but lower thyroid doses compared to 3D CRT. For 3D CRT (which used a noncoplanar field configuration), eye doses were 3-6% and for IMRT (which used a coplanar field configuration) 27-30% of the treatment dose, respectively. For thyroid and more distant organs, doses were less than 1% of the treatment dose. Comparison of measured doses and doses calculated by the treatment planning system (TPS) showed that the TPS underestimated out-of-field doses both for IMRT and 3D CRT.

U radu je razvijena metoda brzog, pouzdanog i jednostavnog istovremenog određivanja 89, 90Sr na koloni u kompleksnim uzorcima iz okoliša, s granicom detekcije koja zadovoljava najstrože propise. U cilju smanjenja udjela ljudskog rada, trajanja analize i proizvodnje otpada razvijen je automatizirani sustav vezanja 89, 90Sr na stroncij specifičnoj koloni volumena do 1 mL i odjeljivanja od svih interferirajućih elementa sa off line detekcijom Čerenkovljevog zračenja direktno na koloni. Istraživanja usmjerena na karakterizaciju visoko specifičnih smola za izolaciju stroncija iz kompleksnih matica (utemeljenih na principima molekularnog prepoznavanja) pokazala su kako SuperLig 620 ima visok afinitet prema stronciju iz širokog raspona koncentracija dušične kiseline, ali i klorovodične kiseline, visoko je selektivan te ne mijenja svojstva pri različitim ispitanim brzinama protoka od 1 do 10 mL/min. Stoga je korištenjem SuperLig 620 pronađen optimalan postupak koncentriranja i izolacije 89, 90Sr i 90Y iz tekućih i krutih uzoraka te njihovog odjeljivanja od interferirajućih elementa uz visoku učinkovitost izolacije stroncija iz uzoraka različitih sastava (voda, tlo, vegetacija). Primjenom ravnotežno disperzijskog modela kromatografije studirana je osjetljivost kolona punjenih različitim visoko specifičnim smolama na varijacije koncentracije stroncija i prisutnost drugih elementa s ciljem predviđanja maksimalne učinkovitosti izolacije. Rezultati dobiveni razvojem i optimiranjem metode Čerenkovljeve sukcesivne detekcije na koloni pokazali su kako se smanjenjem anizotropnosti Čerenkovljevog zračenja može povećati učinkovitost detekcije. Kolona na kojoj je vezan stroncij prije detekcije stavlja se u scintilacijsku bočicu napunjenu vodom kako bi se povećalo raspršenje proizvedenih fotona i povećala učinkovitost detekcije Čerenkovljevog zračenja. Dodatno, prisutnost nitratnih iona u uzorku odnosno na koloni povećava učinkovitost detekcije brojanjem uzoraka na Tri-Carb instrumentu, korištenjem opcije za niskoaktivne uzorke. Tijekom istraživanja osmišljen je upravljački program pomoću kojeg se vodi automatizirani sustav koji se sastoji od sekvencijskih ventila, peristaltičke pumpe i kolona. Radi proširenja omjera aktivnosti 89Sr/90Sr u kojem je moguće brzo i pouzdano odrediti oba izotopa, razvijena metoda usmjerena je na detekciju izotopa na koloni odmah nakon izolacije i naknadnog eluiranja 90Y pomoću 0, 01 mol/L HNO3 samo nekoliko sati nakon prirasta, a radi dodatnog skraćivanja vremena analize, DGA kolona spojena je u seriju sa SuperLig kolonom, gdje se odmah nakon odjeljivanja, 89Sr odredi na SuperLig koloni, a 90Sr preko 90Y vezanog na DGA kolonu. Na temelju provedenih istraživanja kreiran je automatizirani postupak izolacije koji je u kombinaciji s razvijenom tehnikom detekcije na koloni rezultirao razvojem pouzdane i brze metode određivanja 89, 90Sr koja zahtijeva minimalan ljudski angažman, te bitno skraćuje vrijeme analize (trajanje analize sada najviše ovisi o tehničkim karakteristikama instrumenta). Razvijena metoda testirana je određivanjem oba izotopa u interkomparacijskim uzorcima dobivenih od međunarodnih organizacija (Analytics, ERA, IAEA) te je dokazano kako je primjenjiva za različite vrste uzoraka od niskoaktivnog otpada pa sve do morske vode gdje je moguće odrediti i koncentraciju aktivnosti 90Sr manju od 0, 3 Bq/L. Dodatno, dokazano je da je metodologija primjenjiva i za izolaciju 210Pb, te njegovo gama-spektrometrijsko određivanje u uzorcima vode. Primjenom novorazvijenog minijaturiziranog eksperimentalnog postava i automatiziranog postupka izolacije 89, 90Sr te off line Čerenkovljeve detekcije direktno na koloni bitno je skraćeno vrijeme trajanja analize, uz smanjenje udjela ljudskog rada, potrošnje reagenasa i posljedično proizvedenog otpada.

Cultural heritage objects that are radiation treated in order to stop their biodegradation often contain ornamenting materials that cannot be removed. Radiation may produce unwanted changes to such materials. Nacre is a common ornamenting material so this is an attempt to assess the impact of gamma-radiation on its optical properties. Two types of nacre (yellow and white) were obtained from a museum and subjected to different absorbed doses of Co-60 gamma irradiation under the same conditions. The radiation induced changes of nacres color were investigated with fiber optic reflectance spectroscopy (FORS). Colorimetry in CIE Lab space revealed that in both nacres the lightness shifted to darker grey hues at high doses while the color component's (red, green, yellow and blue) behavior depended on the nacre type. Observable changes occurred at doses much above the dose range needed for radiation treatment of cultural heritage objects that are often ornamented with nacre. In UV–vis reflectance spectra of samples irradiated to high doses carbonate radical anion absorption appeared.

Interventional cardiac procedures may be associated with high patient doses and therefore require special attention to protect the patients from radiation injuries such as skin erythema, cardiovascular tissue reactions or radiation-induced cancer. In this study, patient exposure data is collected from 13 countries (37 clinics and nearly 50 interventional rooms) and for 10 different procedures. Dose data was collected from a total of 14,922 interventional cardiology procedures. Based on these data European diagnostic reference levels (DRL) for air kerma-area product are suggested for coronary angiography (CA, DRL = 35 Gy cm2), percutaneous coronary intervention (PCI, 85 Gy cm2), transcatheter aortic valve implantation (TAVI, 130 Gy cm2), electrophysiological procedures (12 Gy cm2) and pacemaker implantations. Pacemaker implantations were further divided into single-chamber (2.5 Gy cm2) and dual chamber (3.5 Gy cm2) procedures and implantations of cardiac resynchronization therapy pacemaker (18 Gy cm2). Results show that relatively new techniques such as TAVI and treatment of chronic total occlusion (CTO) often produce relatively high doses, and thus emphasises the need for use of an optimization tool such as DRL to assist in reducing patient exposure. The generic DRL presented here facilitate comparison of patient exposure in interventional cardiology. © 2018 Associazione Italiana di Fisica Medica

Proton beam therapy has advantages in comparison to conventional photon radiotherapy due to the physical properties of proton beams (e.g. sharp distal fall off, adjustable range and modulation). In proton therapy, there is the possibility of sparing healthy tissue close to the target volume. This is especially important when tumours are located next to critical organs and while treating cancer in paediatric patients. On the other hand, the interactions of protons with matter result in the production of secondary radiation, mostly neutrons and gamma radiation, which deposit their energy at a distance from the target. The aim of this study was to compare the response of different passive dosimetry systems in mixed radiation field induced by proton pencil beam inside anthropomorphic phantoms representing 5 and 10 years old children. Doses were measured in different organs with thermoluminescent (MTS-7, MTS-6 and MCP-N), radiophotoluminescent (GD-352 M and GD-302M), bubble and poly-allyl-diglycol carbonate (PADC) track detectors. Results show that RPL detectors are the less sensitive for neutrons than LiF TLDs and can be applied for in-phantom dosimetry of gamma component. Neutron doses determined using track detectors, bubble detectors and pairs of MTS-7/MTS-6 are consistent within the uncertainty range. This is the first study dealing with measurements on child anthropomorphic phantoms irradiated by a pencil scanning beam technique.

The feasibility of setting-up generic, hospital-independent dose alert levels to initiate vigilance on possible skin injuries in interventional procedures was studied for three high-dose procedures (chemoembolization (TACE) of the liver, neuro-embolization (NE) and percutaneous coronary intervention (PCI)) in 9 European countries. Gafchromic® films and thermoluminescent dosimeters (TLD) were used to determine the Maximum Skin Dose (MSD). Correlation of the online dose indicators (fluoroscopy time, kerma- or dose-area product (KAP or DAP) and cumulative air kerma at interventional reference point (Ka,r)) with MSD was evaluated and used to establish the alert levels corresponding to a MSD of 2 Gy and 5 Gy. The uncertainties of alert levels in terms of DAP and Ka,r, and uncertainty of MSD were calculated. About 20-30% of all MSD values exceeded 2 Gy while only 2-6% exceeded 5 Gy. The correlations suggest that both DAP and Ka,r can be used as a dose indicator for alert levels (Pearson correlation coefficient p mostly >0.8), while fluoroscopy time is not suitable (p mostly

Self-assembled molecules (SAMs) form layers on copper that have an advantage compared to traditional corrosion inhibitors because of the significant decrease of chemical application. The protective properties of such films can be improved by different procedures of application of the SAM layer. In this work, a SAM layer of elaidic acid, a monounsaturated long-chain fatty acid with trans geometrical configuration, was applied on copper surface. Gamma irradiation was used to improve the protective properties of the SAM layer toward corrosion in 3% NaCl. Influence of gamma irradiation on such layer’s properties was studied by different electrochemical techniques (polarization measurements, EIS), contact angle measurements and FTIR analysis. The results have shown that gamma irradiation at doses 0.5–5 kGy improves the protective properties of the SAM. The surface film became thinner due to stronger adsorption and resulted in better ordering of molecules on the surface of the oxide film although the polymerization involving the participation of oxygen molecules has been initiated by irradiation.

Intenzivna upotreba fosilnih goriva (ugljen, nafta) za proizvodnju energije i za pokretanje prometnih vozila tijekom 20. stoljeća uzrokovala je porast koncentracije CO2 u atmosferi. Upotreba biogenih materijala kao zamjene za fosilna goriva može usporiti porast atmosferske koncentracije CO2. Europska unija poreznom politikom stimulira korištenje biogenih goriva te se javlja potreba razvoja neovisne i pouzdane metode za određivanje udjela biogene komponente u različitim vrstama materijala koji se mogu koristiti kao izvori energije. Jedna od takvih metoda je metoda radioaktivnog ugljika (14C) koja se zasniva na različitoj koncentraciji 14C u biogenim i fosilnim materijalima: biogeni materijali odražavaju koncentraciju aktivnosti 14C u suvremenoj atmosferi i biosferi, dok fosilni materijali ne sadrže 14C. Metoda se može primijeniti na različite materijale (mješoviti komunalni otpad, iskorištene auto-gume, drvena građa, tekuća goriva, proizvodi široke potrošnje, CO2 nastao spaljivanjem otpada, i slično). Ovisno o vrsti materijala, mogu se primijeniti različite tehnike mjerenja. Posebna pozornost posvetit će se tehnici određivanja biogene komponente u tekućim gorivima mjerenjem koncentracije aktivnosti 14C u gorivima pomoću tekućinskog scintilacijskog brojača.

European Union’s promotion of the use of sustainable and renewable resources requires use of at least 10 % of synthesized biodiesel in liquid fuels by the year 2020. This legislation has stimulated various types of petrodiesel and bio-based component blends production, and development of methods for exact, effective and reliable quantification of biodiesel content. The method for determination of the biogenic fraction in liquid fuels by direct measurement of the 14C activity concentration via liquid scintillation counting (LSC) technique was developed in few laboratories worldwide. It is based on different 14C signatures of the two components: the biogenic component reflects the modern atmospheric 14C activity, while no 14C is present in fossil fuels. The quantity of 14C in the fuel is the criterion for bio-fuel presence. A great variety of biogenic matrices in fuels results in a wide range of quenching properties of different fuel mixtures. The laboratories participating in this intercomparison study developed two different calibration techniques. The Ruđer Bošković Institute data evaluation method is based on calibration curves for purely biogenic and purely fossil liquids, and does not depend on the exact chemical composition of the organic liquid. The limits of the method are defined by the SQP of app. 690 below which the count rate of biogenic and fossil liquids become indistinguishable from one another. The University of Novi Sad data evaluation method is very dependent on the composition of the examined fuels, so the obtained results in this case were relatively good. Future investigation should also test whether this calibration method is suitable for some other fuel matrices, for example for various types of domestic oil used in everyday life. Testing advantages and limitations of the two methods will continue in the future.

Sustavno praćenje aktivnosti 14C atmosferskog CO2 i bioloških uzoraka (voće – uglavnom jabuke, povrće, žitarice, kukuruz) u neposrednoj okolici Nuklearne elektrane Krško (NEK) provodi se od 2006. godine s ciljem procjene mogućeg utjecaja NEK-a na razinu aktivnosti 14C u okolišu te na efektivnu dozu koju primi lokalno stanovništvo putem prehrane. Posebna je pozornost posvećena praćenju utjecaja remonta elektrane, koji se provodi svakih 18 mjeseci, na aktivnost 14C u okolišu. U radu će se pokazati značajke aktivnosti 14C u okolišu elektrane i neki zaključci zasnovani na dugogodišnjem iskustvu monitoringa. Atmosferski CO2 sakuplja se na dvije lokacije unutar kruga NEK-a, obično u dvomjesečnim intervalima te u kraćim intervalima tijekom i neposredno nakon remonta. Biološki materijal koji integrira 14C iz atmosfere tijekom relativno kratkog vegetacijskog razdoblja (plodovi jabuke, kukuruz, žitarice i slično) skuplja se na početku vegetacijskog razdoblja (lipanj ili srpanj) te ujesen (prije berbe, rujan ili listopad) na više lokacija u unutarnjem i vanjskom krugu. Referentni uzorci bilja sakupljaju se na kontrolnoj točki kraj Dobove, 11, 2 km (zračna udaljenost) jugoistočno od NEK-a, na kojoj se ne očekuje utjecaj zračnih ispusta iz NEK-a. Praćenje aktivnosti 14C u okolici NEK u razdoblju od 2006. do kraja 2016. godine pokazuje da je utjecaj 14C ispuštenog u okoliš zračnim putem mjerljiv i u atmosferskom CO2 i u biljkama koje koriste CO2 za fotosintezu. Taj je utjecaj kratkoročan i prostorno ograničen na najbližu okolinu. Uočena je korelacija između ukupno ispuštene aktivnosti A14C i izmjerenih vrijednosti a14C u CO2 i u bilju. Systematic and continuous monitoring 14C activity in atmospheric CO2 and biological samples (mostly apples, vegetable, cereals, corn) in the vicinity of the Nuclear Power Plant Krško (NEK) in Slovenia has been performed since 2006. The aim of the monitoring is to determine 14C distribution in a close vicinity of the power plant and to estimate possible contribution of NEK to the effective dose of the local population through food chain. In this paper we describe some characteristics of the 14C distribution in the environment of NEK. The 14C activity of atmospheric CO2 at two locations inside the NEK area is on the average slightly higher than that in Zagreb. It depends on the 14C activity (A14C) released in air-born effluent. The influence of the 14C releases has been observed also in plants. Higher 14C activity in plants is most pronounced shortly after spring refuelling, when plants use atmospheric CO2 that contains 14C released from NEK. The influence of the released air-born 14C activity is measurable in both atmospheric CO2 and in plants; the higher the activity of gaseous effluent, the higher the atmospheric and plant 14C activity. However, the influence is temporally and spatially limited. Average 14C activity in plants at the control location Dobova does not differ from the average atmospheric 14C activity in Zagreb. It was shown earlier that the slightly increased 14C activity in plants does not contribute significantly to the effective dose of the local population due to ingestion of 14C. According to the experience of the whole monitoring, 14C is the only released radionuclide detected in the environment of NEK (Report IJS-DP-12059).

Zbornik sadrži 61 rad na hrvatskom ili engleskom jeziku s obveznim engleskim sažetkom. Radovi su organizirani u sekcije: Etika i kultura u zaštiti od zračenja, Opće teme, Zaštita od zračenja i dozimetrija u medicini, Biološki učinci zračenja. Instrumentacija i mjerne tehnike, Radioekologija, Radon, Izloženost stanovništva zračenju, Neionizirajuća zračenja The Proceedings contains 61 papers in Croatian or English with an obligatory English 1-page abstract. Papers are organized in the following sections: Ethics and culture in radiation protection, General topics, Radiation protection and dosimetry in medicine, Biological effects of radiation, Instrumentation and measuring techniques, Radioecology, Radon, Public exposure and Nonionising radiation

For the preparation of Gamma Knife (GK) treatments of brain tumours, a head CT examination is necessary when using a new CT-based convolution dose calculation algorithm included in Leksell Gamma Plan software (version 10.1.1). The purpose of this study was to measure the organ doses in paediatric anthropomorphic phantoms during a head CT scan and compare them with the measured GK treatment doses. CT doses were measured with radiophotoluminescence (RPL) dosimeters and compared with results of MC simulations. Measured doses for organs within the CT scan volume were comparable for both phantoms. The highest organ CT dose was evaluated for eyes: 27.6 ± 0.2 mGy and 27.3 ± 0.6 mGy for 5 and 10 year old phantom respectively. Doses for organs not included in the scan volume decreased with distance from the scan volume and were on average 3.5 times higher for the 5 year old phantom compared with the 10 year old phantom. Comparison of measured and MC dose values showed good agreement. For the 10 year old phantom, CT doses were 22%, 6%, 5% and 3% of the GK dose for thyroid, lungs, eyes and breasts respectively. Enhancement of the total organ doses for the whole GK treatment due to CT scanning is not negligible but nevertheless, the use of the new convolution algorithm seems reasonable.

Purpose: To develop a simple model of therapeutic and stray absorbed dose for a variety of treatment machines and techniques without relying on proprietary machine-specific parameters. Methods: Dosimetry measurements conducted in this study and from the literature were used to develop an analytical model of absorbed dose from a variety of treatment machines and techniques in the 6 to 25 MV interval. A modified one-dimensional gamma-index analysis was performed to evaluate dosimetric accuracy of the model on an independent dataset consisting of measured dose profiles from seven treatment units spanning four manufacturers. Results: The average difference between the calculated and measured absorbed dose values was 9.9% for those datasets on which the model was trained. Additionally, these results indicate that the model can provide accurate calculations of both therapeutic and stray radiation dose from a wide variety of radiotherapy units and techniques. Conclusions: We have developed a simple analytical model of absorbed dose from external beam radiotherapy treatments in the 6 to 25 MV beam energy range. The model has been tested on measured data from multiple treatment machines and techniques, and is broadly applicable to contemporary external beam radiation therapy.

The fraction of biogenic component within various types of materials that can be used as fuels for energy production and transport can be determined by measuring their 14C activity. The method is based on different 14C signatures of the biogenic and the fossil components: while the biogenic component reflects the modern atmospheric 14C activity, no 14C is present in fossil fuels. A direct measurement of the 14C content in liquid fuel by liquid scintillation counter is a simple and fast technique but has a main disadvantage: different liquid colors cause different quenching properties and affect the measurement efficiency. We propose a new evaluation technique that uses liquids of different colors to construct modern and background calibration curves. Various binary mixtures of biogenic liquids have been used to verify the relation between the count rate and the quenching parameter. Mixtures of a biogenic and a 14C-free liquid demonstrated the potential of the proposed technique for determining the biogenic fraction of a mixture.

During the First Symposium on Radiological Protection in Portorož (Slovenia), October 8 – 12, 1963, Yugoslav Radiation Protection Association (YRPA) was formed. Members from Croatia participated in all YRPA activities. YRPA members (3) participated at the First IRPA Congress, Rome 1963. YRPA became a full member of IRPA in 1969 (IRPA had 17 members at that time!). Croatian Radiation Protection Association (CRPA, in Croatian: Hrvatsko društvo za zaštitu od zračenja, HDZZ, www.hdzz.hr) was founded in 1979 and has continued to function within YRPA until 1991. As independent society CRPA became a regular member of IRPA in 1992. Today CRPA has 170 members – from research and university, medicine, regulatory and governmental bodies, industry… Main activities of CRPA: Organization of symposia (national with international participation, regional); International cooperation; Organization of lectures; Cooperation with regulatory bodies, participation in professional committees, members provide advice and assistance to authorities; Spread of information; Involvement of young scientists and practitioners. International cooperation: 1 - Regional level – with Hungary, Slovenia, Serbia, Bosnia and Herzegovina, Montenegro, Austria, Romania; 2 - European level – active participants at the European RP meetings, organization of the meeting 2009; 3 - International - Co-operation with IRPA.

14C activity in the atmospheric CO2 and in biological samples in the close vicinity of the Krško Nuclear Power Plant (NPP) in Slovenia has been regularly monitored since 2006 with the aim of estimating a possible influence of the NPP on environmental 14C levels and on the effective dose of local population through food chain. Atmospheric CO2 on two locations was collected every two months, or in shorter periods during some refuelling periods. Biological samples (apples, corn, wheat, grass, vegetables) were collected twice a year (in summer and autumn) in two circles around the NPP, inner and outer, and at the control point 12 km from the plant. Increase of 14C activity in atmospheric CO2 was observed during and immediately after the refuelling of the power plant, performed every 18 months. Good correlation between the total 14C activity released in gaseous effluents and the 14C activity of the atmospheric CO2 has been observed. 14C activity in plants collected close to the Krško NPP is always higher than the activities on the control point, and depends both on the distance from the exhaust of the plant ventilation system and on wind direction: it is higher on the location in the SW-NE direction that coincided with the most pronounced wind directions. Higher 14C activities have been determined in plants collected in summer after the spring refuelling than in those collected during the following vegetation period after the autumn refuelling. This can be explained by the uptake of the CO2 of higher 14C activity for the process of photosynthesis after spring refuelling. To estimate the realistic effective dose due to ingestion to the population in the vicinity, a model of food consumption has been proposed. The calculated dose for the population at the NPP vicinity is not significantly different from the dose for the population at the control point.

Laboratorij za mjerenje niskih radioaktivnosti Instituta Ruđer Bošković (IRB) u Zagrebu redovito sudjeluje u međunarodnim inter-komparacijama za određivanje koncentracije aktivnosti tricija (3H) u vodama i aktivnosti 14C u raznim vrstama materijala. U ovom radu prikazani su rezultati sudjelovanja u dvjema interkomparacijama, IAEA-TRIC2012 za 3H i SIRI (Sixth International Radiocarbon Intercomparison) za 14C. Koncentracija aktivnosti (A) 3H u vodama određuje se tehnikom elektrolitičkog obogaćenja vode tricijem i mjerenjem tekućinskim scintilacijskim brojačem (LSC) Quantulus 1220. Scintilacijski koktel sastoji se od 8 mL obogaćene vode i 12 mL scintilatora UltimaGold LLT. Uređaj za elektrolitičko obogaćenje sastoji se od 20 ćelija volumena 500 mL, a prosječni faktor obogaćenja je E = 23, 6 ± 2, 3. Relativna specifična aktivnost 14C (a14C) uzoraka iz kojih se može izdvojiti 4 g ugljika određuje se radiometrijski tehnikom pripreme benzena i mjerenjem u LSC-u. Za mjerenje aktivnosti 14C u uzorcima znatno manje mase

Povišenje koncentracije CO2 u atmosferi tijekom 20. stoljeća posljedica je intenzivnog korištenja fosilnih goriva. Smanjenje emisije CO2 nastalog izgaranjem fosilnih goriva proizvodnjom energije iz biogenih materijala (biogoriva) danas se stimulira i poreznom politikom pa se javlja potreba kontrole proizvođača i distributera goriva primjenom pouzdane metode određivanja udjela biogene komponente u gorivima. Jedna od metoda za određivanje udjela biogene komponente u smjesi fosilnog i biogoriva je 14C metoda, koja se zasniva na različitoj koncentraciji izotopa 14C u pojedinim komponentama smjese: biogoriva odražavaju 14C aktivnost suvremene atmosfere, dok fosilna goriva ne sadrže 14C. Za tekuća goriva moguće je primijeniti tehniku direktnog mjerenja u tekućinskom scintilacijskom brojaču (LSC) uz dodatak odgovarajućeg scintilatora. U ovom radu ćemo prikazati novu tehniku direktnog mjerenja koja koristi karakteristike gašenja zbog boje za kalibraciju brojača. Određivanje udjela biogene komponente u tekućim gorivima moguće je direktnim mjerenjem sadržaja 14C tekućinskim scintilacijskim brojačem. Tehnika obrade rezultata razvijena na IRB daje rezultate usporedive s drugačijom tehnikom korištenom na IJS. Donja granica detekcije je oko 0, 5 % biogene komponente, a tehnika se može primijeniti na sve vrste goriva bez obzira na fosilnu matricu i vrstu biogenog aditiva.

Rapid screening of strontium activity in waters via Cherenkov radiation detection by ultra-low-level liquid scintillation counter Quantulus 1220 was established in two laboratories, Laboratory for low radioactivity of the Department of Physics, University of Novi Sad, Serbia (UNS) and Laboratory for measurements of low-level radioactivities at the Ruđer Bošković Institute, Zagreb, Croatia (RBI). Optimization of the method comprises choice of an appropriate vial type, selection of optimal spectral window, determination of the counting efficiency in various vials, evaluation of the influence of vial on efficiency and background. The efficiency of the measurement of A(90Sr) in plastic vials is 45.6 % and 37.3 % at UNS and RBI, respectively, while in glass vials it is lower (~32 %). Background count rate is lower in plastic than in glass vials, resulting in better counting properties of the plastic vials. The achieved minimum detectable activity for a total counting time of 300 min was 0.32 Bq∙L-1 in plastic vials at UNS and 0.34 Bq L-1 at RBI. Validation of the method was performed by determination of strontium level in spiked samples within interlaboratory comparison measurements. The A(90Sr) values determined in both laboratories did not deviate significantly from the spiked activities, giving the z-scores in the interval [-2, 2]. Only one sample at RBI had the z-score higher than 2 but lower than 3. All results from UNS had positive z-score values, including the sample measured within the IAEA proficiency test. The 90Sr/90Y Cherenkov radiation measurements of water samples can be successfully used for rapid screening of samples without any pretreatment of the samples.

Determination of gamma ray dose in mixed neutron+gamma ray fields is still a demanding task. Dosemeters used for gamma ray dosimetry are usually in some extent sensitive to neutrons and their response variations depend on neutron energy i.e., on neutron spectra. Besides, it is necessary to take into account the energy dependence of dosemeter responses to gamma rays. In this work, several types of thermoluminescent detectors (TLD) placed in different holders used for gamma ray dose determination in the mixed fields were examined. Dosemeters were from three different institutions: Ruđer Boskovic Institute (RBI), Croatia, Jožef Stefan Institute (JSI), Slovenia and Autoridad Regulatoria Nuclear (ARN), Argentina. All dosemeters were irradiated during the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002. Three accidental scenarios were reproduced and in each irradiation the dosemeters were exposed placed on the front of phantom and ‘free in air’. Following types of TLDs were used: 7 LiF (TLD-700), CaF 2 :Mn and Al 2 O 3 :Mg,Y—all from RBI; CaF 2 :Mn from JSI and 7 LiF (TLD-700) from ARN. Reported doses were compared with the reference values as well as with the values obtained from the results of all participants. The results show satisfactory agreement with other dosimetry systems used in the Intercomparison. The influence of different types of holders and applied corrections of dosemeters' readings are discussed.

Selective determination of the fast neutron component in a mixed radiation field by the TL dosimetry was studied. TL responses due to the induced radioactivity in Al2O3:C dosimeters via the 27Al(n, gamma)24Na reaction were used to measure the neutron part in a mixed 14.5 MeV neutron and gamma irradiation field. The lowest detectable neutron dose was found to be in order of 10 mSv of personal dose equivalent for Al2O3:C.

International audience; The first objective of this work was to check and select a set of four kinds of passive photon, dosimeters (two thermo-luminescence dosimeter (TLD) types, one radiophotoluminescence (RPL) dosimeter and one optically stimulated luminescence (OSL) dosimeter) together with a common measurement protocol. Dosimeters were calibrated in a reference clinical linear acccelerator beam in a water tank at a reference facility at the Laboratoire National Henri Becquerel (CEA LIST/LNE LNHB, Saclay. Radiation qualities of 6, 12 and 20 MV were used with standard calibration conditions described in IAEA TRS 398 and non-standard conditions. Profile and depth dose ion chamber measurements were also made to provide reference values. Measurements were made in a water tank into which pipes could be inserted which held dosimeters in pre-determined and reproducible positions. The water tank was built to enable investigation of doses up to 60 cm from the beam axis. A first set of experiments was carried out with the beam passing through the tank. From this first experiment, penumbra and out-of-field dose profiles including water and collimator scatter and leakage were found over three orders of magnitude. Two further sets of experiments using the same experimental arrangement with the beam outside the tank, to avoid water scatter, were designed to measure collimator scatter and leakage by closing the jaws of the collimator. Depending on the energy, typical leakage and collimator scatter represents 10–40% and 30–50% of the total out-of-field doses respectively. It was concluded that all dosimeters can be used for out-of-field photon dosimetry. All show good uniformity, good reproducibility, and can be used down to low doses expected at distances remote from the subsequent radiotherapy target volume.

Zbornik sadrži 86 radova na hrvatskom ili engleskom jeziku, a svaki rad ima i jednu stranicu engleskog sažetka. Radovi su podijeljeni u cjeline: Okrugli stol, Opće teme, Dozimetrija zračenja, Biološki učinci zračenja, Izloženost stanovništva zračenju, Zaštita od zračenja u medicini, Radioekologija, Instrumentacija i mjerne tehnike.

LiF thermoluminescent material doped with Mg, Cu and Si recently developed by the Korea Atomic Energy Research Institute (KAERI) has shown very good dosimetric properties. Since the thermoluminescence in LiF was found to be dependent on the proper combination of dopants, the investigation of the concentration and type of dopants is very important in developing and characterisation of new TL materials. The aim of this work was to determine the influence of type and concentration of activators on the glow curve structure, sensitivity, reproducibility and on the photon energy response of LiF:Mg, Cu, Si detectors. The energy response was studied in air and on the ISO water phantom in the range of mean photon energies between 33 keV and 164 keV. The morphology and local chemical composition of LiF:Mg, Cu, Si detectors were examined using high resolution scanning electron microscopy (FE-SEM). The results show that type and concentration of activators influence the glow curve and sensitivity. Different dopant concentrations did not show influence on the photon energy response. The sensitivity of LiF:Mg, Cu, Si detector with dopant concentration of Mg=0.35 mol%, Cu=0.025 mol% and Si=0.9 mol% was very high (up to 65 times higher than that of TLD-100). The photon energy response of LiF:Mg, Cu, Si detectors containing all three dopants in various concentrations is in accordance with the IAEA recommendations for individual monitoring.

Radiophotoluminescence (RPL) dosimetry systems are under permanent development. The following dosimetric characteristics of the GD-352M RPL glass dosimeter with FGD-1000 reader (Dose Ace system) developed for medical applications were investigated: uniformity/batch homogeneity, reproducibility, linearity, detection threshold, energy dependence in air and on phantom. Some characteristics were compared to two kinds of LiF ; Cu, Mg, P TLDs: GR-200A (China) and TLD-100H (Harshaw). The characteristics investigated fulfill the requirements of the IEC 62387-1:2007 Standard for personal and environmental dosimetry (IEC, 2007). These dosimetry systems were applied in paediatric chest X-ray diagnostics on 60 patients. The dosimetry results with both dosimetry systems showed a good correlation of dose measured on the back of the patient with the body mass index (BMI) on examination by two technicians (average dose 0.12-0.19 mSv). Higher doses (0.33-0.39 mSv) were found on the patients examined by the third technician. Measurements on further 40 patients following additional consulting and education of the technicians showed dose reduction (0.13-0.18 mSv for all 3 technicians).

This work studied the percent depth doses of (60)Co photon beams in the buildup region of a plastic phantom by LiF TLD measurements and by Monte Carlo calculations. An agreement within +/-1.5% was found between PDDs measured by TLD and calculated by the Monte Carlo method with the TLD in a plastic phantom. The dose in the plastic phantom was scored in voxels, with thickness scaled by physical and electron density. PDDs calculated by electron density scaling showed a better match with PDD(TLD)(MC); the difference is within +/-1.5% in the buildup region for square and rectangular field sizes.

Within this study five different types of material were used as luminescence dosimetry phosphors for recording environmental radiation doses. The material was TLD400 and TLD500 phosphors, quartz from two different geological origins (quartzite rock veins and quartz sand) and salt and the techniques were Thermo- and Optically- Stimulated -Luminescence. The phosphors were buried within homogenised and sieved natural soil for periods ranging from 1 to 19 weeks. The luminescence analysis examined for signal sensitivity, dose response and signal growth. The results report well measured doses of only some weeks when using Optical Luminescence besides the well studied TLD400/500 phosphors also for quartz and salt samples. With Thermoluminescence, only TLD400/500 could reliably monitor doses corresponding to some weeks. The study concludes that quartz and salt could be routinely used as dosimetry phosphors to correctly estimate doses resulted from only some months of average to low radiation environments.

Recently, two new types of tissue equivalent thermoluminescent detectors (TLDs) have aroused attention: LiF:Mg,Cu,Na,Si and Li2B4O7:Cu,Ag,P. In this work the characteristics of both detectors were compared with the characteristics of the well-known type LiF:Mg,Ti detector, TLD-100. The following properties were investigated: the glow curve structures, relative sensitivity, batch homogeneity and uniformity, detection threshold, reproducibility of the response, linearity in the wide dose range and fading. Also, the energy dependence for medium and low energy X rays was determined in the range of mean energies between 33 and 116 keV. The results confirmed tissue equivalency of both new types in the investigated range of photon energies. LiF:Mg,Cu,Na,Si detector has very high sensitivity (similar to 75 times higher than that of TLD-100) and is convenient for use in a very low range of doses. Li2B4O7:Cu,Ag,P detector shows some improvements in comparison with the previously prepared types of lithium borate. The most important is the five times higher sensitivity than that of TLD-100. This detector is also very promising, especially in medical dosimetry. 14th International Conference on Solid State Dosimetry, Jun 27-Jul 02, 2004, New Haven, CT

The aim of this work was to determine energy dependence characteristics in terms of values of the personal dose equivalent, HP(10). The following types of thermoluminescent detectors (TLDs) were investigated: (a) two new types based on lithium borate, Li_2B_4O_7:Cu, In and Li_2B_4O_7:Cu, In, Ag ; (b) two types based on the highly sensitive material LiF:Mg, Cu, P, TLD-700H and GR 200A ; (c) two well-known types of LiF:Mg, Ti detector, TLD-100 and TLD-700 and (d) highly sensitive Al:2O_3:C detectors. TLDs previously calibrated with Cs-137 gamma rays, were simultaneously irradiated with X ray beams in the range of mean energies between 33 and 116 keV. The irradiations were performed with detectors in polymethyl methacrylate (PMMA) holders placed on a 30 cm X 30 cm X 15 cm water phantom with PMMA walls (ISO phantom). Measured energy responses were compared with calculated data for Hp(10) values. The results confirmed the satisfactory tissue equivalent characteristics of all investigated TLDs except Al_2O_3:C, which (due to its large energy dependence) is suitable for personal dosimetry only with an appropriate filter.

The aim of this work was to determine important dosimetric characteristics of several types of the most interesting tissue-equivalent thermoluminescent detectors (TLDs). Special attention was given to the determination of energy dependence for medium and low energy X rays. The following types of TLDs were investigated: (a) two new types based on lithium borate: Li2B4O7:Cu, In and Li2B4O7:Ctl, In, Ag ; (b) two types of the recently developed highly sensitive LiF:Mg, Cu, P material: TLD-700H and GR 200A and (c) two well known types of LiF:mG, Ti detectors: TLD-100 and TLD-700. In order to determine their photon energy response characteristics, TLDs previously calibrated with (CS)-C-137 gamma rays were simultaneously irradiated with X ray beams in the range of effective energies between 33 and 116 keV. Measured energy responses (relative to air), normalised to those to (CS)-C-137 photons were compared with calculated data. Although the deviations of the measured data from the "theoretical" predictions are different for all the investigated TLDs, there is no large difference in "tissue-equivalency" between them.

Most of the patients in the intensive care unit for children are newborns and infants having an infection of the central nervous system, with systemic septic and respiratory infections. Therefore, mobile X-ray equipment including mobile shields is routinely used for diagnosis of the respiratory tract, heart and endovascular cateterisation. The aim of this work was to determine the radiation exposure to the children in the vicinity of the exposed patient in the same or next room. Three measurement runs were carried out with thermoluminescence dosimetry system. The results show that the homogeneity of the irradiation field is adequate, the exposure of children to radiation in the vicinity of the exposed patient in the same or next room is very low, practically in the range of the lowest detectable dose. The entrance dose on the breast of the patient was found to be 0.07 mSv. Therefore, there is no basis for the risk estimation of genetic, leukemogenic and cancerogenic detriment.

The high gamma sensitivity demonstrated by LiF:Mg, Cu, P produced in China and Poland makes it appropriate for environmental applications. Recently a new version of this material has been produced in the United States in both loose chip and encapsulated card form. This study investigates the performance of the US material under conditions designed to simulate environmental insults as described in ANSI Draft Standard N13.29. Twenty dosimeters are placed in an environmental chamber that cycles twice through three 15 day periods of temperature and humidity conditions: -20 degrees C ; +50 degrees C with 20% relative humidity ; and +50 degrees with 90% relative humidity. Five randomly selected dosimeters are exposed to a 137Cs source to doses between 0.5 to 10.0 mSv at the beginning, middle, and end of the 90-day test. Two 40-watt fluorescent bulbs provide lighting in the chamber. Performance is measured by comparison with the proposed Draft N13.29 performance criteria that would require the absolute value of the bias and standard deviation to each be less than or equal to 0.35, while their sum must be less than or equal to 0.50.

The combination of fluoroscopically guided interventional procedures with computed tomography (CTF) has become widespread around the world. The benefits of CTF include the ability to obtain a real-time visualization of the entire body, increased target accuracy and improved visualization of biopsy needles. Modern CTF units work with variable frame rates for image selection, and therefore the dose distributions for patients and staff can considerably vary, creating growing concern in terms of the occupational exposure of interventionists and the drawback of a higher exposure of the patient. A literature review of the latest CTF publications is summarized in this article. A wide range of CTF studies reveal different treatment methods used in clinical practice, and therefore the differences in the exposures between them ; as well as in the radiation protection tools and dose monitoring. Further optimization of radiation protection methods, harmonization of exposure patterns as well as training and education of CTF staff on the basis of the information in the survey, are strongly recommended.