1,328 research outputs found

    Брахитерапия низкой и высокой мощности дозы в комбинации с дистанционной лучевой терапией и андроген-депривационной терапией у больных раком предстательной железы высокого риска

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    Background. Prostate cancer (PCa) in the Russian Federation takes the leading place in the prevalence of cancer among the male population.Objective: to investigate the effect of increasing a single focal dose in high-dose-rate brachytherapy (HDR-BT) in combination with external beam radiotherapy on biochemical failure-free survival and local control in patients with high-risk PCa. Materials and methods. The study included 350 men with PCa in the group of high and extremely high risk of progression. All patients included in the study were divided into 4 groups. Groups 1, 2 and 3 included 276 patients who received HDR-BT with a 192Ir source with a single dose per fraction: 10 Gy (n = 83), 12 Gy (n = 46) and 15 Gy (n = 147). Group 4 included 74 patients who received low-dose-rate brachytherapy with 125I sources up to a total focal dose of 110 Gy. At the 2 stage, external beam radiotherapy was a conventional fractionation (single dose of 2 Gy, total - 44-46 Gy).Results. Of 350 patients over a 5-year follow-up period, PCa recurrence was noted in 65 (18.6 %). The 3- and 5-year biochemical failure-free survival rates in the general cohort of patients were 87.4 and 81.4 %. 5-year biochemical failure-free survival was significantly higher in group 3 relative to group 4 and amounted to 89.8 and 74.2 % (p = 0.03). Increasing the dose for HDR-BT from 10 to 12 Gy per fraction significantly reduced the frequency of local relapses from 15.7 % (in group 1) to 2.2 % (in group 2) (p = 0.0001) while maintaining the level of genitourinary and gastrointestinal toxicity. Conclusion. The use of a combination of brachytherapy and external beam radiotherapy in patients with high risk PCa is highly effective in achieving local control of the tumor. The optimal fractionation regime for HDR-BT remains a matter of debate. The use of 15 Gy per fraction for HDR-BT in combination with external beam radiotherapy is the most optimal fractionation regimen in patients with high-risk PCa.Введение. Рак предстательной железы (РПЖ) в России продолжает занимать лидирующее место по распространенности среди онкологических заболеваний мужского населения.Цель исследования - изучить влияние увеличения разовой очаговой дозы при брахитерапии высокой мощности дозы (HDR-БТ) в комбинации с дистанционной лучевой терапией на безрецидивную выживаемость и локальный контроль над опухолью у больных РПЖ высокого риска прогрессирования.Материалы и методы. В исследование были включены 350 мужчин с РПЖ группы высокого и крайне высокого риска прогрессирования. Все пациенты были разделены на 4 группы. В 1, 2 и 3-ю группы вошли 276 пациентов, которым в качестве boost применялась HDR-БТ источником 192Ir с разовой дозой за 1 фракцию 10 Гр (n = 83), 12 Гр (n = 46) и 15 Гр (n = 147) соответственно. В 4-ю группу вошли 74 пациента, которым использовалась брахитерапия низкой мощности дозы источниками 125I до суммарной очаговой дозы 110 Гр. На 2-м этапе проводилась дистанционная лучевая терапия на зону предстательной железы и регионарного лимфооттока в стандартном режиме фракционирования (разовая доза 2 Гр, суммарная доза 44-46 Гр).Результаты. Из 350 пациентов за 5 лет наблюдения рецидив РПЖ отмечен у 65 (18,6 %) больных. В общей когорте пациентов 3- и 5-летняя специфическая выживаемость по уровню простатического специфического антигена (ПСА) составила 87,4 и 81,4 % соответственно. ПСА-специфическая 5-летняя выживаемость была достоверно выше в 3-й группе, чем в 4-й, и составила 89,8 и 74,2 % соответственно (р = 0,03). Увеличение дозы при HDR-БТ с 10 до 12 Гр за фракцию достоверно снизило частоту локальных рецидивов с 15,7 % (в 1-й группе) до 2,2 % (во 2-й группе) (p = 0,0001) при сохранении уровня генитоуринарной и гастроинтестинальной токсичности.Заключение. Применение комбинации брахитерапии и дистанционной лучевой терапии у больных РПЖ высокого риска прогрессирования характеризуется высокой эффективностью в достижении локального контроля над опухолью. Оптимальный режим фракционирования при HDR-БТ остается предметом обсуждения. Использование дозы 15 Гр за фракцию при HDR-БТ в комбинации с дистанционной лучевой терапией является наиболее оптимальным режимом фракционирования у больных РПЖ высокого риска

    Observation of an Excited Bc+ State

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    Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date

    Measurement of the inelastic pp cross-section at a centre-of-mass energy of 13TeV

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    The cross-section for inelastic proton-proton collisions at a centre-of-mass energy of 13TeV is measured with the LHCb detector. The fiducial cross-section for inelastic interactions producing at least one prompt long-lived charged particle with momentum p > 2 GeV/c in the pseudorapidity range 2 < η < 5 is determined to be ϭ acc = 62:2 ± 0:2 ± 2:5mb. The first uncertainty is the intrinsic systematic uncertainty of the measurement, the second is due to the uncertainty on the integrated luminosity. The statistical uncertainty is negligible. Extrapolation to full phase space yields the total inelastic proton-proton cross-section ϭ inel = 75:4 ± 3:0 ± 4:5mb, where the first uncertainty is experimental and the second due to the extrapolation. An updated value of the inelastic cross-section at a centre-of-mass energy of 7TeV is also reported

    Measurement of CPCP violation in B0Dπ±B^{0}\rightarrow D^{\mp}\pi^{\pm} decays

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    A measurement of the CPCP asymmetries SfS_{f} and SfˉS_{\bar{f}} in B0Dπ±B^0\to D^{\mp}\pi^{\pm} decays is reported. The decays are reconstructed in a dataset collected with the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV and corresponding to an integrated luminosity of 3.0fb13.0 \rm{ fb}^{-1}. The CPCP asymmetries are measured to be Sf=0.058±0.020(stat)±0.011(syst)S_{f} = 0.058 \pm 0.020 (\rm{stat}) \pm 0.011(\rm{syst}) and Sfˉ=0.038±0.020(stat)±0.007(syst)S_{\bar{f}} = 0.038\pm 0.020 (\text{stat})\pm 0.007 (\text{syst}). These results are in agreement with, and more precise than, previous determinations. They are used to constrain sin(2β+γ)|\sin\left(2\beta+\gamma\right)| and γ\gamma to intervals that are consistent with the current world-average values.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2018-009.htm

    Evidence for the decay BS0K0μ+μ {B}_S^0\to {\overline{K}}^{\ast 0}{\mu}^{+}{\mu}^{-}

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    International audienceA search for the decay BS0K0μ+μ {B}_S^0\to {\overline{K}}^{\ast 0}{\mu}^{+}{\mu}^{-} is presented using data sets corresponding to 1.0, 2.0 and 1.6 fb1^{−1} of integrated luminosity collected during pp collisions with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, respectively. An excess is found over the background-only hypothesis with a significance of 3.4 standard deviations. The branching fraction of the BS0K0μ+μ {B}_S^0\to {\overline{K}}^{\ast 0}{\mu}^{+}{\mu}^{-} decay is determined to be B(Bs0K0μ+μ)=[2.9±1.0(stat)±0.2(syst)±0.3(norm)]×108 \mathrm{\mathcal{B}}\left({B}_s^0\to {\overline{K}}^{\ast 0}{\mu}^{+}{\mu}^{-}\right)=\left[2.9\pm 1.0\left(\mathrm{stat}\right)\pm 0.2\left(\mathrm{syst}\right)\pm 0.3\left(\mathrm{norm}\right)\right]\times {10}^{-8} , where the first and second uncertainties are statistical and systematic, respectively. The third uncertainty is due to limited knowledge of external parameters used to normalise the branching fraction measurement

    Measurement of the branching fraction and CP asymmetry in B plus . J/.. plus decays

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    The branching fraction and direct C ⁣PC\!P asymmetry of the decay B+J/ψρ+B^{+}\rightarrow J/\psi \rho^{+} are measured using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV, corresponding to a total integrated luminosity of 3\mbox{fb}^{-1}. The following results are obtained: \begin{align} \mathcal{B}(B^{+}\rightarrow J/\psi \rho^{+}) &= (3.81 ^{+0.25}_{-0.24} \pm 0.35) \times 10^{-5}, \nonumber \\ \mathcal{A}^{C\!P} (B^{+}\rightarrow J/\psi \rho^{+}) &= -0.045^{+0.056}_{-0.057} \pm 0.008, \nonumber \end{align} where the first uncertainties are statistical and the second systematic. Both measurements are the most precise to date.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2018-036.htm

    Observation of the Decay Λ0b→Λ+cτ−¯ν

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    The first observation of the semileptonic b-baryon decay Λb0→Λc+τ-ν¯τ, with a significance of 6.1σ, is reported using a data sample corresponding to 3 fb-1 of integrated luminosity, collected by the LHCb experiment at center-of-mass energies of 7 and 8 TeV at the LHC. The τ- lepton is reconstructed in the hadronic decay to three charged pions. The ratio K=B(Λb0→Λc+τ-ν¯τ)/B(Λb0→Λc+π-π+π-) is measured to be 2.46±0.27±0.40, where the first uncertainty is statistical and the second systematic. The branching fraction B(Λb0→Λc+τ-ν¯τ)=(1.50±0.16±0.25±0.23)% is obtained, where the third uncertainty is from the external branching fraction of the normalization channel Λb0→Λc+π-π+π-. The ratio of semileptonic branching fractions R(Λc+)B(Λb0→Λc+τ-ν¯τ)/B(Λb0→Λc+μ-ν¯μ) is derived to be 0.242±0.026±0.040±0.059, where the external branching fraction uncertainty from the channel Λb0→Λc+μ-ν¯μ contributes to the last term. This result is in agreement with the standard model prediction

    Measurement of forward top pair production in the dilepton channel in <i>pp</i> collisions at √s=13 TeV

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    Forward top quark pair production is studied in pppp collisions in the μeb\mu eb final state using a data sample corresponding to an integrated luminosity of 1.93 fb1^{-1} collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The cross-section is measured in a fiducial region where both leptons have a transverse momentum greater than 20 GeV and a pseudorapidity between 2.0 and 4.5. The quadrature sum of the azimuthal separation and the difference in pseudorapidities, denoted ΔR\Delta R, between the two leptons must be larger than 0.1. The bb-jet axis is required to be separated from both leptons by a ΔR\Delta R of 0.5, and to have a transverse momentum in excess of 20 GeV and a pseudorapidity between 2.2 and 4.2. The cross-section is measured to be σttˉ=126±19(stat)±16(syst)±5(lumi)fb\sigma_{t\bar{t}}= 126\pm19\,(\mathrm{stat})\pm16\,(\mathrm{syst})\pm5\,(\mathrm{lumi})\,\,\mathrm{ fb} where the first uncertainty is statistical, the second is systematic, and the third is due to the luminosity determination. The measurement is compatible with the Standard Model prediction.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2017-050.htm

    Search for CPCP violation through an amplitude analysis of D0K+Kπ+πD^0 \to K^+ K^- \pi^+ \pi^- decays

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    International audienceA search for CP violation in the Cabibbo-suppressed D0^{0} → K+^{+}K^{−}π+^{+}π^{−} decay mode is performed using an amplitude analysis. The measurement uses a sample of pp collisions recorded by the LHCb experiment during 2011 and 2012, corresponding to an integrated luminosity of 3.0 fb1^{−1}. The D0^{0} mesons are reconstructed from semileptonic b-hadron decays into D0^{0}μ^{−}X final states. The selected sample contains more than 160 000 signal decays, allowing the most precise amplitude modelling of this D0^{0} decay to date. The obtained amplitude model is used to perform the search for CP violation. The result is compatible with CP symmetry, with a sensitivity ranging from 1% to 15% depending on the amplitude considered

    Observation of the doubly charmed baryon decay Ξcc++→Ξc′+π+

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    The Ξcc++→Ξc′+π+ decay is observed using proton-proton collisions collected by the LHCb experiment at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1. The Ξcc++→Ξc′+π+ decay is reconstructed partially, where the photon from the Ξc′+→Ξc+γ decay is not reconstructed and the pK−π+ final state of the Ξc+ baryon is employed. The Ξcc++→Ξc′+π+branching fraction relative to that of the Ξcc++→Ξc+π+ decay is measured to be 1.41 ± 0.17 ± 0.10, where the first uncertainty is statistical and the second systematic. [Figure not available: see fulltext.
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