231 research outputs found
6.3 MeV fast neutrons in the treatment of patients with locally advanced and locally recurrent breast cancer
The study included 135 breast cancer patients (70 patients with locally recurrent breast cancer and 65 patients with locally advanced breast cancer with unfavorable prognostic factors) who received the neutron therapy alone or in combination with the photon therapy. The neutron therapy was shown to be effective in multimodality treatment of patients with locally advanced and locally recurrent breast cancer.The 8-year survival rate in patients without repeated breast cancer recurrence was 87.6±8.7% after the neutron and neutron-photon therapy and 54.3±9.2% after the electron beam therapy
6.3 MeV fast neutrons in the treatment of patients with locally advanced and locally recurrent breast cancer
The study included 135 breast cancer patients (70 patients with locally recurrent breast cancer and 65 patients with locally advanced breast cancer with unfavorable prognostic factors) who received the neutron therapy alone or in combination with the photon therapy. The neutron therapy was shown to be effective in multimodality treatment of patients with locally advanced and locally recurrent breast cancer.The 8-year survival rate in patients without repeated breast cancer recurrence was 87.6±8.7% after the neutron and neutron-photon therapy and 54.3±9.2% after the electron beam therapy
Novel technologies and theoretical models in radiation therapy of cancer patients using 6.3 MeV fast neutrons produced by U-120 cyclotron
The analysis of clinical use of neutron therapy with 6 MeV fast neutrons compared to conventional radiation therapy was carried out. The experience of using neutron and mixed neutron and photon therapy in patients with different radio-resistant malignant tumors shows the necessity of further studies and development of the novel approaches to densely-ionizing radiation. The results of dosimetry and radiobiological studies have been the basis for planning clinical programs for neutron therapy. Clinical trials over the past 30 years have shown that neutron therapy successfully destroys radio-resistant cancers, including salivary gland tumors, adenoidcystic carcinoma, inoperable sarcomas, locally advanced head and neck tumors, and locally advanced prostate cancer. Radiation therapy with 6.3 MeV fast neutrons used alone and in combination with photon therapy resulted in improved long-term treatment outcomes in patients with radio-resistant malignant tumors
Neutron Therapy for Salivary and Thyroid Gland Cancer
The purpose of this study was to analyze the results of the combined modality treatment and radiation therapy using 6.3 MeV fast neutrons for salivary gland cancer and prognostically unfavorable thyroid gland cancer. The study group comprised 127 patients with salivary gland cancer and 46 patients with thyroid gland cancer, who received neutron therapy alone and in combination with surgery. The results obtained demonstrated that the combined modality treatment including fast neutron therapy led to encouraging local control in patients with salivary and thyroid gland cancers
An observation of the meson in the system in the Pion- Interaction at Momentum of 29 GeV
The charge-exchange reaction ,
, is studied with
the upgraded VES facility (U-70, Protvino) in the interaction of a 29 GeV pion
beam with a beryllium target. The distribution over the invariant mass of the
system shows a near-threshold signal. A partial wave analysis
reveals that the scalar state () dominates in this mass region.
The observed signal can be described with a contribution of the known
resonance . Using OPE approximation for the reaction the product of branching fractions is found to be:
Compton Scattering by the Proton using a Large-Acceptance Arrangement
Compton scattering by the proton has been measured using the tagged-photon
facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The new
data are interpreted in terms of dispersion theory based on the SAID-SM99K
parameterization of photo-meson amplitudes. It is found that two-pion exchange
in the t-channel is needed for a description of the data in the second
resonance region. The data are well represented if this channel is modeled by a
single pole with mass parameter m(sigma)=600 MeV. The asymptotic part of the
spin dependent amplitude is found to be well represented by pi-0-exchange in
the t-channel. A backward spin-polarizability of
gamma(pi)=(-37.1+-0.6(stat+syst)+-3.0(model))x10^{-4}fm^4 has been determined
from data of the first resonance region below 455 MeV. This value is in a good
agreement with predictions of dispersion relations and chiral pertubation
theory. From a subset of data between 280 and 360 MeV the resonance
pion-photoproduction amplitudes were evaluated leading to a E2/M1 multipole
ratio of the p-to-Delta radiative transition of EMR(340
MeV)=(-1.7+-0.4(stat+syst)+-0.2(model))%. It was found that this number is
dependent on the parameterization of photo-meson amplitudes. With the MAID2K
parameterization an E2/M1 multipole ratio of EMR(340
MeV)=(-2.0+-0.4(stat+syst)+-0.2(model))% is obtained
and photoproduction with fine center-of-mass energy resolution
Measurements of and cross-sections have been obtained with the photon
tagging facility and the Crystal Ball calorimeter at MAMI-C. The measurement
uses a novel meson identification technique in which the weak decay
products are characterized using the energy and timing characteristics of the
energy deposit in the calorimeter, a method that has the potential to be
applied at many other facilities. The fine center-of-mass energy ()
resolution and statistical accuracy of the new data results in a significant
impact on partial wave analyses aiming to better establish the excitation
spectrum of the nucleon. The new analyses disfavor a strong role for
quark-diquark dynamics in the nucleon.Comment: 7 pages, 8 figure
A new measurement of the neutron detection efficiency for the NaI Crystal Ball detector
We report on a measurement of the neutron detection efficiency in NaI
crystals in the Crystal Ball detector obtained from a study of single p0
photoproduction on deuterium using the tagged photon beam at the Mainz
Microtron. The results were obtained up to a neutron energy of 400 MeV. They
are compared to previous measurements made more than 15 years ago at the pion
beam at the BNL AGS
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