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Patrick W Serruys - One of the best experts on this subject based on the ideXlab platform.
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late outcome after intracoronary Beta Radiation brachytherapy a matched propensity controlled ten year follow up study
Eurointervention, 2011Co-Authors: Jin M Cheng, Patrick W Serruys, Peter C Levendag, Yoshinobu Onuma, Jannet A Eindhoven, Ron T Van Domburg, Wim J Van Der GiessenAbstract:Aims: Increased major adverse cardiac events (MACE) beyond six months after intracoronary β Radiation brachytherapy (IRBT) are a major concern. The aim of this study was to evaluate the 10-year clinical outcome after IRBT. Methods and results: From 1997 to 2002, 301 consecutive patients treated with IRBT were included prospectively, whereafter 602 control patients treated with conventional percutaneous coronary intervention (PCI) were matched by propensity score methodology. MACE was defined as all-cause death, any myocardial infarction or any revascularisation. Median follow-up duration was 9.7 years. Mortality rates in both groups were similar. Cumulative 5-month, 2-, and 10- year MACE-free survival rates of IRBT patients were 89%, 56% and 29%, respectively, while those of the control patients were 90%, 76% and 52%, respectively (p<0.001). The difference in the MACE rate was mainly driven by target vessel revascularisation (TVR) (p<0.001). Furthermore, two or more repeat TVRs were needed in 12% of IRBT patients and in only 6% of control patients (p<0.01). Adjusted hazard ratios for IRBT-associated all-cause mortality and MACE were 1.0 (95% CI 0.7-1.5) and 1.8 (95% CI 1.5-2.2), respectively. Conclusion: IRBT was associated with increased MACE between five months and two years of follow-up, mainly driven by repeat revascularisations. Similar event rate after two years indicate that there were no very late adverse effects related to IRBT.
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direct stenting versus direct stenting followed by centered Beta Radiation with intravascular ultrasound guided dosimetry and long term anti platelet treatment results of a randomized trial Beta Radiation investigation with direct stenting and galile
Journal of the American College of Cardiology, 2004Co-Authors: Patrick W Serruys, Georgios Sianos, William Wijns, Ivan De Scheerder, Paul Van Den Heuvel, Wolfgang Rutsch, Helmut D Glogar, Carlos Macaya, P Materne, Susan VeldhofAbstract:Objectives We sought to assess the efficacy of vascular brachytherapy (VBT) combined with stenting for the primary prevention of restenosis. Background Intravascular brachytherapy after stent implantation for de novo lesions has been abandoned for the present. We revisited this procedure by optimizing all procedural steps—the use of glycoprotein IIb/IIIa blockers, direct stenting, adequate Radiation coverage, avoidance of edge damage, source centering, intravascular ultrasound-guided dosimetry, and continuation of a dual anti-platelet regimen for one year. Methods The Beta-Radiation Investigation with Direct stenting and Galileo in Europe (BRIDGE) study is a multicenter, randomized controlled trial evaluating the long-term efficacy of VBT with P-32 (20 Gy at 1 mm in the coronary wall) after direct stenting. The primary end point was angiographic intra-stent late loss; secondary end points were six months binary restenosis and neo-intimal hyperplasia. Patients (n = 112) with de novo lesions (2.5 to 4.0 mm in diameter up to 15 mm long) were randomized to either VBT or no-VBT. Results At six months, intra-stent loss was 0.43 and 0.84 mm (p Conclusions Despite the optimization of pre-, peri-, and post-procedural factors and despite the relative efficacy of the brachytherapy for the prevention of the intra-stent neo-intimal hyperplasia, the clinical outcome of the irradiated group was less favorable than that of the control group.
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geographical miss during catheter based intracoronary Beta Radiation incidence and implications in the brie study
Journal of the American College of Cardiology, 2001Co-Authors: Georgios Sianos, Evelyn Regar, Clemens Disco, Patrick I Kay, M A Costa, Ken Kozuma, Pim J De Feyter, Eric Boersma, Patrick W SerruysAbstract:OBJECTIVES We sought to determine the incidence and causes of geographical miss (GM) and to evaluate its impact on edge restenosis after intracoronary Beta-Radiation therapy. BACKGROUND Edge restenosis is a limitation of intracoronary Beta-Radiation therapy. Geographical miss is the situation in which the Radiation source does not fully cover the injured segment and may lead to edge restenosis. METHODS We analyzed 175 vessels treated according to the Beta-Radiation In Europe (BRIE) study protocol. The effective irradiated segment (EIRS) and both edges were studied with quantitative coronary angiography. The edges of the EIRS that were injured constituted the GM edges. Restenosis was defined as diameter stenosis >50% at follow-up. Geographical miss was determined by simultaneous electrocardiographic-matched, side-by-side projection of the source and balloons deflated at the injury site, in identical angiographic projections surrounded by contrast. RESULTS Geographical miss affected 41.2% of the edges and increased edge restenosis significantly compared with non-GM edges (16.3% vs. 4.3%, respectively, p = 0.004). Restenosis was increased both in the proximal (p = 0.05) and distal (p = 0.02) GM edges compared with noninjured edges. Geographical miss associated with stent injury significantly increased edge restenosis (p = 0.006), whereas GM related to balloon injury did not significantly increase edge restenosis (p = 0.35). The restenosis in the EIRS was similar between vessels with and without GM (24.3% and 21.6%, respectively, p = 0.8). CONCLUSIONS Geographical miss is strongly associated with restenosis at the edges of the EIRS. This effect is more prominent when caused by stenting. Geographical miss does not increase restenosis in the EIRS.
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endoluminal Beta Radiation therapy for the prevention of coronary restenosis after balloon angioplasty
The New England Journal of Medicine, 2001Co-Authors: Vitali Verin, Clemens Disco, William Wijns, Youri Popowski, Bernard De Bruyne, Wolfgang Sauerwein, Markus Lins, Gyorgy Kovacs, F Calman, Patrick W SerruysAbstract:Background Beta Radiation is effective in reducing vascular neointimal proliferation in animals after injury caused by balloon angioplasty. However, the lowest dose that can prevent restenosis after coronary angioplasty has yet to be determined. Methods After successful balloon angioplasty of a previously untreated coronary stenosis, 181 patients were randomly assigned to receive 9, 12, 15, or 18 Gy of Radiation delivered by a centered yttrium-90 source. Adjunctive stenting was required in 28 percent of the patients. The primary end point was the minimal luminal diameter six months after treatment, as a function of the delivered dose of Radiation. Results At the time of follow-up coronary angiography, the mean minimal luminal diameter was 1.67 mm in the 9-Gy group, 1.76 mm in the 12-Gy group, 1.83 mm in the 15-Gy group, and 1.97 mm in the 18-Gy group (P=0.06 for the comparison of 9 Gy with 18 Gy), resulting in restenosis rates of 29 percent, 21 percent, 16 percent, and 15 percent, respectively (P=0.14 for...
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geometric vascular remodeling after balloon angioplasty and Beta Radiation therapy a three dimensional intravascular ultrasound study
Circulation, 1999Co-Authors: Manel Sabate, Patrick W Serruys, Patrick I Kay, V L M A Coen, Jurgen Ligthart, Alexander J Wardeh, A L Gijzel, Willem J Van Der Giessen, Ad Den Boer, Peter C LevendagAbstract:Background—Endovascular Radiation appears to inhibit intimal thickening after overstretching balloon injury in animal models. The effect of brachytherapy on vascular remodeling is unknown. The aim of the study was to determine the evolution of coronary vessel dimensions after intracoronary irRadiation after successful balloon angioplasty in humans. Methods and Results—Twenty-one consecutive patients treated with balloon angioplasty and b-Radiation according to the Beta Energy Restenosis Trial-1.5 were included in the study. Volumetric assessment of the irradiated segment and both edges was performed after brachytherapy and at 6-month follow-up. Intravascular ultrasound images were acquired by means of ECG-triggered pullback, and 3-D reconstruction was performed by automated edge detection, allowing the calculation of lumen, plaque, and external elastic membrane (EEM) volumes. In the irradiated segments, mean EEM and plaque volumes increased significantly (4516128 to 490.96159 mm 3 and 201.2659 to 241.7674 mm 3 ; P50.01 and P50.001, respectively), whereas luminal volume remained unchanged (250.8691 to 249.26102 mm 3 ; P5NS). The edges demonstrated an increase in mean plaque volume (26.8612 to 32.6610 mm 3 , P50.0001) and no net change in mean EEM volume (71.4624 to 70.9624 mm 3 , P5NS), resulting in a decrease in mean luminal volume (44.6616 to 38.3616 mm 3 , P50.01). Conclusions—A different pattern of remodeling is observed in coronary segments treated with b-Radiation after successful balloon angioplasty. In the irradiated segments, the adaptive increase of EEM volume appears to be the major contributor to the luminal volume at follow-up. Conversely, both edges showed an increase in plaque volume without a net change in EEM volume. (Circulation. 1999;100:1182-1188.)
S Fedina - One of the best experts on this subject based on the ideXlab platform.
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direct comparison of extrapolation chamber measurements of the absorbed dose rate for Beta Radiation between ptb germany and vniim russia
Metrologia, 2011Co-Authors: R Behrens, S Fedina, A OborinAbstract:An intercomparison of the absorbed dose rate in tissue, , at Radiation protection levels for Beta dosimetry was performed between two national metrology institutes, the D I Mendeleyev Institute for Metrology (VNIIM) in St Petersburg (Russia) and the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig (Germany), from 2009 to 2010. For this comparison, Radiation sources of both institutes were calibrated using the primary standard measuring devices (extrapolation chambers) of both institutes, i.e. no transfer instrument was used as both primary standards were directly compared. The values of the absorbed dose rates in tissue agree within 1.2% for two different 90Sr/90Y sources, within 1.0% for one 85Kr source and within 1.5% and 4.2% for two different 147Pm sources. All these deviations are within 1 to 2 times the corresponding standard deviations.
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comparison of extrapolation chamber measurements of the absorbed dose rate for Beta Radiation between vniim russia and ptb germany
Metrologia, 2004Co-Authors: K Helmstadter, J Bohm, P Ambrosi, V Fominych, E Rumyantseva, S FedinaAbstract:A comparison of absorbed dose rates, t(0.07), in tissue at Radiation protection levels for Beta dosimetry was performed between two national laboratories, the D I Mendeleyev Institute for Metrology (VNIIM) in St Petersburg (Russia) and the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig (Germany), in 1999 and 2001 using flat ionization chambers as transfer standards. The dose rates were determined at the calibration distances by measurements with the primary standard measuring devices of VNIIM and PTB with extrapolation chambers to realise the unit of absorbed dose rate to tissue for Beta Radiation. In the two steps reported on here, transfer chambers of VNIIM and PTB were calibrated in Beta Radiation reference fields at VNIIM and at PTB. The values of the calibration factors for the flat ionization chambers agreed within ±2% for 90Sr/90Y, 85Kr and 204Tl and ±4% for 147Pm Beta Radiation. 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 EUROMET, according to the provisions of the Mutual Recognition Arrangement (MRA).
R Behrens - One of the best experts on this subject based on the ideXlab platform.
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simulation of the Radiation fields of the Beta secondary standard bss 2
Journal of Instrumentation, 2013Co-Authors: R BehrensAbstract:Since several years, the irRadiation facility for Beta Radiation, the Beta Secondary Standard BSS 2 developed at PTB, is in worldwide use to irradiate devices with calibrated Beta sources. In this work the electron and photon particle spectra of the BSS 2 Radiation fields are made available as data files, in addition angular distributions and the depth dose profiles are given. The spectra were determined using the Monte Carlo particle transport code BEAMnrc and are provided as electronic files. In order to verify the simulations, from the same simulations the depth dose curves in a phantom were deduced and compared with corresponding measurements — the agreement is quite good — proving the correctness of the particle spectra.
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direct comparison of extrapolation chamber measurements of the absorbed dose rate for Beta Radiation between ptb germany and vniim russia
Metrologia, 2011Co-Authors: R Behrens, S Fedina, A OborinAbstract:An intercomparison of the absorbed dose rate in tissue, , at Radiation protection levels for Beta dosimetry was performed between two national metrology institutes, the D I Mendeleyev Institute for Metrology (VNIIM) in St Petersburg (Russia) and the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig (Germany), from 2009 to 2010. For this comparison, Radiation sources of both institutes were calibrated using the primary standard measuring devices (extrapolation chambers) of both institutes, i.e. no transfer instrument was used as both primary standards were directly compared. The values of the absorbed dose rates in tissue agree within 1.2% for two different 90Sr/90Y sources, within 1.0% for one 85Kr source and within 1.5% and 4.2% for two different 147Pm sources. All these deviations are within 1 to 2 times the corresponding standard deviations.
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international comparison euromet ri i s2 of extrapolation chamber measurements of the absorbed dose rate in tissue for Beta Radiation euromet project no 739 final report
Metrologia, 2007Co-Authors: R Behrens, K Helmstadter, P Ambrosi, C Lecante, J M Bordy, M Bovi, I Jokelainen, C G Soares, P R B Saull, I A KharitonovAbstract:For quality assurance in the realization and transfer by the national standard laboratories of the unit of the absorbed dose rate at 0.07 mm tissue depth for Beta Radiation, comparison measurements among the primary standard facilities are needed. Although some bilateral comparisons have taken place for this quantity, the CCRI decided in May 2003 that a EUROMET supplementary comparison would be appropriate if inclusive of primary standards laboratories of other regional metrology organizations. The operation and results of such a comparison are reported here. A flat ionization chamber and measurement system was used as the transfer instrument. A comparison was made of the calibration coefficients of this transfer instrument in various Beta-particle laboratory reference fields (Pm-147, Kr-85, Tl-204 and Sr-90/Y-90) measured by each of the eight participants from France, Italy, Finland, Germany, Russian Federation, USA, Canada and Japan. The PTB was the pilot laboratory and the comparison ran from January 2004 until April 2007 under EUROMET project No 739 and EUROMET.RI(I)-S2. The results for most of the participants are consistent with the stated uncertainties although an extreme deviation is apparent for Pm-147 Beta Radiation for one participant. 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 EUROMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
Sule Kaya Keles - One of the best experts on this subject based on the ideXlab platform.
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synthesis thermoluminescence and dosimetric properties of la doped zinc borates
Journal of Luminescence, 2013Co-Authors: Nil Kucuk, Ilker Kucuk, Merve Cakir, Sule Kaya KelesAbstract:Abstract Dependence on the dose of Beta Radiation of undoped and La-doped ZnB 2 O 4 powder samples at 1%, 2%, 3%, 4%, 5% and 10% (by weight) was investigated by thermoluminescence technique. Powder samples were synthesized by the nitric acid method using the starting oxides [zinc oxide (ZnO), boric acid (H 3 BO 3 ) and doped element oxide (La 2 O 3 )]. The samples were characterized by X-ray diffraction (XRD). The thermoluminescence (TL) properties of the powder samples were measured with Riso TL/OSL DA-20 reader. TL glow curves were obtained with heating at a constant heating rate of 5 °C/s up to 450 °C. The dose response curves of the powder samples exposed to 90 Sr Beta Radiation (40 mCi) were obtained in the dose range from 143 mGy to 60 Gy. Dose responses and minimum detectable dose (MDD) values for increasing Radiation doses of the powder samples were determined. The dose responses of all the samples have shown a quite linear response to Beta Radiation. MDD value of 10% La-doped ZnB 2 O 4 powder sample which shows a high temperature peak at 207 °C was determined as 4 mGy. MDD values for 1%, 2%, 3%, 4% and 5% La-doped ZnB 2 O 4 powder samples were also determined as 10 mGy, 50 mGy, 10 mGy, 10 mGy and 30 mGy, respectively. Luminescence intensities of the powder samples were shown to be likely to be used for low Radiation doses.
D J Ottaway - One of the best experts on this subject based on the ideXlab platform.
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a fibre optic based approach and device for sensing Beta Radiation in liquids
Sensors and Actuators A-physical, 2019Co-Authors: Carly A Whittaker, Christopher A G Kalnins, Heike Ebendorffheidepriem, Nigel A Spooner, D J OttawayAbstract:Abstract An optical fibre-based Beta Radiation sensing device has been investigated for the purpose of detecting low levels of the daughter products of Uranium-238 in liquids for mineral processing and environmental monitoring applications. The sensor operates by detecting the scintillation light produced by polymer optical fibres. A range of fibres have been studied by quantifying a number of properties that are critical to their performance including the Beta Radiation scintillation response, transmission loss, and performance under the proposed environmental conditions. Based on these measurements, the most suitable fibre type was incorporated within a prototype sensing device which is capable of performing direct, real-time, continuous measurements of Beta Radiation emitting radionuclides within solutions or suspensions, which is not possible with current measurement techniques. The technology presented here allows for the detection of low levels of Beta Radiation in liquids, which could be useful for the detection of Radiation in mineral processing liquids, municipal water sources, and storage tanks containing nuclear fuel.