Search

Main text In 2009, the Consultative Committee for Ionizing Radiation (CCRI) approved its first supplementary comparison, to be organized by the ENEA (as the pilot laboratory), for the measurement of the alpha and beta particle surface (i.e. 2 solid angle) emission rate from large area sources of the type used for calibrating surface contamination monitors. Five sources were disseminated to the twenty-three participating laboratories consisting of one each of 241Am, 14C, 147Pm and 90Sr for emission rate measurements, with one additional 90Sr source for the evaluation of source uniformity. Measurements of the radionuclide activity and radionuclidic purity were also made although not strictly required. This report describes the organization of this comparison and the material and measurement methods used. The proposed supplementary comparison reference values (SCRV) for each of the comparison measurands are given, together with the Degrees of Equivalence and their associated uncertainties for each participating laboratory. The results of this supplementary comparison may be used as evidence by participating National Metrology Institutes (NMIs) and Designated Institutes (DIs) when submitting calibration and measurement capabilities (CMCs) for the given radionuclides for similar types of large area sources; this is an important aspect of this comparison, given that only one other international supplementary comparison for surface emission rates had been organized before. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A comparison of the activity concentration measurement of a 3H2O solution was organized by the LNE-LNHB under the auspices of the CCRI(II). The solution was sent to thirteen laboratories and eleven measurement reports were received. The results, as well as relevant information on the measurement techniques, are presented and analysed in this paper. All results are consistent within uncertainties. As the solution was traceable to the solution used in the CCRI(II)-K2.H-3 comparison in 2009, the results of both comparisons are also presented. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text In 2016, comparisons of activity measurements of 99mTc, 18F and 64Cu using the Transfer Instrument of the International Reference System (SIRTI) took place at the National Centre for Nuclear Research, Radioisotope Centre (POLATOM, Poland). Ampoules containing about 33 kBq of 99mTc, 28 kBq of 18F and 110 kBq of 64Cu solutions were measured in the SIRTI for about 3, 5 and 1.5 half-lives, respectively. The POLATOM standardized the activity in the ampoules by 4π(LS)β–γ coincidence measurements. The comparisons, identifiers BIPM.RI(II)-K4.Tc-99m, BIPM.RI(II)-K4.F-18 and BIPM.RI(II)-K4.Cu-64, are linked to the corresponding BIPM.RI(II)-K1.Tc-99m, BIPM.RI(II)-K1.F-18 and BIPM.RI(II)-K1.Cu-64 comparisons. The BIPM.RI(II)-K1 99mTc and 18F key comparison reference values have been updated to include the latest BIPM.RI(II)-K4 linked results and degrees of equivalence for both comparison series have been evaluated. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Three new participations in the BIPM.RI(II)-K1.Co-57 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the CCRI(II)-S6.Co-57 comparison piloted by the International Atomic Energy Agency (IAEA) in 2008 for which one sample of the 57Co radioactive solution was sent to the SIR. Two NMIs used the S6 comparison to update their degree of equivalence. The degrees of equivalence between each equivalent activity measured in the International Reference System (SIR) and the KCRV have been calculated and the results are given in the form of a table for the remaining seven NMIs in the BIPM.RI(II)-K1.Co-57 comparison and the three eligible participants in the CCRI(II)-S6.Co-57 comparison. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A bilateral comparison between ENEA-INMRI (Italy) and NCBJ RC POLATOM (Poland) of 131I-solution activity measurements was organized in the year 2015 and piloted by POLATOM, which provided the sources for the comparison. The 131I master solution was standardized independently at both institutes by using Liquid Scintillation Counting and ionization chamber techniques. The 131I master solution was then sent by POLATOM to the BIPM International Reference System (SIR). The comparison was registered as an EURAMET.RI(II)-K2.I-131 key comparison allowing the ENEA-INMRI result to enter in the SIR database.

The gamma emitting impurities in 99mTc solution obtained from enriched molybdenum 100Mo metallic target after its irradiation in a cyclotron were measured using a high-purity germanium (HPGe) detector. The radioactivity range of tested samples of 99mTc was rather low, in the range from 0.34 to 2.39 MBq, thus creating a challenge to investigate the standard measurement HPGe system for impurity detection and quantification. In the process of 99mTc separation from irradiated target the AnaLig® Tc-02 resin, Dionex H+ and Alumina A columns were used. Fractions of eluates from various steps of separation process were taken and measured for radionuclidic purity. The overall measurement sensitivity of gamma emitters in terms of minimum detectable activity (MDA) was found at the level of 14–70 Bq with emission lines in range of 36 – 1836 keV resulting in impurity content range of 6.7 × 10−4 to 3.4 × 10−3 % for 93Tc, 93mTc, 94Tc, 94mTc, 95Tc, 95mTc, 96Tc 96Nb, 97Nb, 99Mo contaminants and 9.4 × 10−3 % for 97mTc. The usefulness of the chosen measurement conditions and the method applied to testing the potential contaminators was proved by reaching satisfactory results of MDAs less than the criteria of impurity concentration of all nuclides specified in the European Pharmacopoeia.

A bilateral comparison of 14C activity measurements between ENEA-INMRI (Italy) and NCBJ RC POLATOM (Poland) was organized in the year 2015 and piloted by POLATOM, which provided the sources for the comparison. A set of six sources in Ultima Gold scintillator was measured at POLATOM using four different counters by two liquid scintillation counting methods: TDCR and CIEMAT/NIST. Three of sources were measured also at ENEA-INMRI by using two different TDCR counters. The results achieved in the comparison show an excellent agreement.

Application of a new coincidence module using the pulse-mixing method in the 4π(LS)-γ coincidence system with TDCR detector in the beta channel (TDCRG) is presented. The pulse-mixing method extended for the TDCR system with gamma channel was compared with the classical coincidence method where the coincidence resolving time is introduced. The characteristics of the resolving and dead time of the above two methods were investigated. The level of accidental coincidences in the system was determined. The new developed coincidence module was validated by activity measurement of a set of 51Cr, 54Mn, 60Co, 65Zn, 85Sr and 134Cs standards.

Activity measurements of 3H, 241Am and 60Co solutions were performed to compare digital coincidence modules used at PTB and POLATOM for TDCR and 4πβ(LS)-γ coincidence counting. The activities determined with various coincidence modules connected in parallel to the same counter at PTB were found to be consistent. Observed discrepancies caused by differences in the coincidence resolving time did not exceed 0.14%. Accidental coincidences simulated by a frequency generator were registered, and the coincidence resolving time was determined.

A comparison of calculations of the activity of a 3H2O liquid scintillation source using the same experimental data set collected at the LNE-LNHB with a triple-to-double coincidence ratio (TDCR) counter was completed. A total of 17 laboratories calculated the activity and standard uncertainty of the LS source, using the files with experimental data. The results, as well as relevant information on the computation techniques are presented and analysed in this paper. All results are compatible, even if there is a significant dispersion between the reported uncertainties. An output of this comparison is the estimation of the dispersion of TDCR measurement results when measurement conditions are well defined. KEY WORDS FOR SEARCH Radionuclide metrology, supplementary comparison, tritium, liquid scintillation Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text A comparison of the activity concentration of an 55Fe solution was organized by the POLATOM under the auspices of the CCRI(II). The solution was sent to thirteen laboratories; ready-to-measure sources were also prepared using the same 55Fe solution in diffusive (polyethylene) vials and sent to twelve laboratories. Twelve measurement reports were received. The results, as well as relevant information on the measurement techniques, are presented and analysed in this paper. The differences in the results obtained from measurements in non-diffusive (glass) and diffusive vials are indicated. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A new 4π(LS)-γ coincidence system (TDCRG) was built at the NCBJ RC POLATOM. The counter consists of a TDCR detector in the beta channel and scintillation detector with NaI(Tl) crystal in the gamma channel. The system is equipped with a digital board with FPGA, which records and analyses coincidences in the TDCR detector and coincidences between the beta and gamma channels. The characteristics of the system and a scheme of the FPGA implementation with behavioral simulation are given. The TDCRG counter was validated by activity measurements on (14)C and (60)Co solutions standardized in RC POLATOM using previously validated methods.

International audience; A comparison of calculations of the activity of a $^3$H$_2$O liquid scintillation source using the same experimental data set collected at the LNE-LNHB with a triple-to-double coincidence ratio (TDCR) counter was completed. A total of 17 laboratories calculated the activity and standard uncertainty of the LS source using the files with experimental data provided by the LNE-LNHB. The results as well as relevant information on the computation techniques are presented and analysed in this paper. All results are compatible, even if there is a significant dispersion between the reported uncertainties. An output of this comparison is the estimation of the dispersion of TDCR measurement results when measurement conditions are well defined.

The aim of the work was to develop new radioactive standard sources based on epoxy resins. The optimal proportions of the components and the homogeneity of the matrices were determined. The activity of multigamma sources prepared in Marinelli beakers was determined with reference to the National Standard of Radionuclides Activity in Poland. The difference of radionuclides activity values determined using calibrated gamma spectrometer and the activity of standard solutions used are in most cases significantly lower than measurement uncertainty limits. Sources production method and quality control procedure have been developed.

A bilateral comparison between ENEA-INMRI (Italy) and NCBJ RC POLATOM (Poland) of

Standardization of 153 Sm by 4π(LS)-γ coincidence and anticoincidence counting and the CIEMAT/NIST method in three LS-counters is presented. This short half-life radionuclide is applied in tumor therapy and bone pain palliation. A simplified disintegration scheme of 153 Sm was applied in the calculation of the counting efficiency. Standard uncertainties of 0.4% for the 153 Sm measurements by the 4π(LS)-γ coincidence and anticoincidence techniques and 0.7% by the C/N method were evaluated, respectively. An agreement of the standardization results by both methods within the respective uncertainties was obtained. The half-life of 153 Sm of (1.92895±0.00024) days was determined during one month of measurements and correction for europium isotope impurities by the C/N method in the TriCarb 2910 LS-counter.

Drug resistance is one of the most important clinical problems in the treatment of ovarian cancer. This study was designed to determine whether expression of p53 could be used as a marker for predicting the response to chemotherapy of ovarian cancer. Tissue blocks were obtained from 187 patients with diagnosed untreated ovarian cancer. Paraffin sections from the primaries were immunohistochemically analysed for p53 expression. All patients underwent platinum-based chemotherapy after surgery. We analysed whether the number of chemotherapy cycles was related to survival in women with p53 positive and p53 negative ovarian cancer. 27/187 cases were p53 positive. Expression of p53 was associated with other factors of unfavourable prognosis. Patients with p53 positive tumours had a significantly worse prognosis compared with patients with p53 negative tumours (P = 0.037). There was a statistically significant dose-response effect of platinum-based chemotherapy in patients with p53 negative tumours, which could not be seen in patients with p53 positive tumours (P = 0.01 versus P = 0.553). This could also be observed in patients with residual tumour after surgery (P = 0.0001 versus P = 0.8866). Expression of p53 may be an additional useful marker in predicting response to chemotherapy. Thus, it is possible to identify a subgroup of patients who may benefit from alternative therapy regimens.

The prognostic value of various molecular markers, which adequately account for the tumor biology and disease behaviour of ovarian cancer, is still unclear. Recent studies have focused on the role of genes regulating the balance between proliferation and cellular suicide, apoptosis. In the present study, tumor tissue from 215 patients with ovarian cancer was immunohistochemically analysed for Bax- and Bcl-2-expression. There was an association between Bcl-2-expression (30%) and factors of favourable prognosis. In contrast, Bax-expression (47%) was related to bad clinical outcome, especially in cases without concomitant Bcl-2-expression. In patients with Bcl-2-positive/Bax-negative tumors, overall survival was significantly longer (p = 0.0379) than in patients with Bcl-2- and Bax-negative tumors. Respectively, expression of Bax without Bcl-2-expression was correlated with bad clinical outcome (p = 0.033). The difference in overall survival was most striking (p = 0.0007) between patients with Bax-positive/Bcl-2-negative and Bcl-2-positive/Bax-negative tumors. This could also be demonstrated for the various subgroups of different tumor grade and stage. It may be speculated, that alteration of the Bax/Bcl-2-balance may influence the clinical course by deregulation of programmed cell death and altered sensitivity to chemotherapy.

Identification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 × 10-8) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD. ASTAR (Agency for Sci., Tech. and Research, S’pore) NMRC (Natl Medical Research Council, S’pore)