RESUMO
The purpose of this study was to evaluate boron distribution for a safe and effective BNCT (Boron Neutron Capture Therapy) of liver metastases. Samples both from healthy and tumour liver parenchyma were analysed, after i.v. boron administration, by: alpha particles counting under neutron irradiation; morphological analysis by standard haematoxylin-eosin staining; neutron autoradiography. Our method was unaffected by the cytological heterogeneity inside tumour nodules; it demonstrated selective boron distribution in tumour tissue and predicted estimated mean therapeutic doses in tumour and safety doses in healthy tissue. The time interval for efficient BNCT was 2 to 4 hours after i.v. boron administration.
Assuntos
Terapia por Captura de Nêutron de Boro , Boro/farmacocinética , Neoplasias Colorretais/patologia , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/secundário , Animais , Masculino , Ratos , Distribuição TecidualAssuntos
Compostos de Boro/uso terapêutico , Neoplasias do Colo/patologia , Neoplasias do Colo/radioterapia , Neoplasias Hepáticas/secundário , Fenilalanina/análogos & derivados , Radiossensibilizantes/uso terapêutico , Partículas alfa , Animais , Células de Kupffer/patologia , Células de Kupffer/ultraestrutura , Fígado/patologia , Fígado/ultraestrutura , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/ultraestrutura , Ativação de Macrófagos , Nêutrons , Fagocitose , Fenilalanina/uso terapêutico , Ratos , Ratos EndogâmicosRESUMO
Almost eight years ago, in December 2001, we performed for the first time in the world thermal neutron irradiation on an isolated liver of a patient. The organ was affected by diffuse metastases of a colon carcinoma and had been previously loaded with a (10)B compound. In July 2003, the same procedure was applied again on a patient for the treatment of unresectable and incurable hepatic metastases of a carcinoma of the rectum. Both patients are dead at present. Now we can analyze in depth the clinical history of these patients and evaluate the effectiveness of this therapy. From this exciting experience we learned much, and we also found out about complications till then unknown, which need to be studied and addressed experimentally. Unfortunately we can base our conclusions just on the experience we had with these two patients. We could have been much more detailed and firm in our statements if the number of clinical cases was larger. The BNCT Pavia project has been suspended, but it is more than likely to resume in a short time. Good findings were many. The procedure is feasible; the original concept of complete immersion of the diseased liver in a homogeneous neutron field proved effective and winning. The tumor masses resulted completely necrotic and unknown metastases too appeared radically treated; healthy hepatic tissue was preserved from both morphological and functional points of view; no symptoms of cirrhosis appeared even four years after treatment. For the long term surviving patient, quality of life was excellent. Other findings require to be tackled in depth. The "post-irradiation syndrome" we observed in both patients, with identical symptoms and biochemical derangements, creates a dramatic--even though totally reversible--clinical condition, that is the probable cause of death for our second patient, suffering from cardiomyopathy, 33 days after treatment. For the first patient, recurrences were a late yet fatal complication, for which even a further surgical revision was ineffective. We offer some hypotheses about their origin and possible prevention.
Assuntos
Terapia por Captura de Nêutron de Boro/métodos , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/secundário , Adulto , Compostos de Boro/administração & dosagem , Compostos de Boro/uso terapêutico , Terapia por Captura de Nêutron de Boro/efeitos adversos , Cardiomiopatia Dilatada/etiologia , Quimioterapia do Câncer por Perfusão Regional/métodos , Neoplasias do Colo , Circulação Extracorpórea , Humanos , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Necrose , Fenilalanina/administração & dosagem , Fenilalanina/análogos & derivados , Fenilalanina/uso terapêutico , Lesões por Radiação/etiologia , Radiossensibilizantes/administração & dosagem , Radiossensibilizantes/uso terapêutico , Neoplasias Retais , Tomografia Computadorizada por Raios XRESUMO
The ability to selectively hit the tumour cells is an essential characteristic of an anti-tumour therapy. In boron neutron capture therapy (BNCT) this characteristic is based on the selective uptake of (10)B in the tumour cells with respect to normal tissues. An important step in the BNCT planning is the measurement of the boron concentration in the tissue samples, both tumour and healthy. When the tumour is spread through the healthy tissue, as in the case of metastases, the knowledge of the different kinds of tissues in the sample being analysed is crucial. If the percentage of tumour and normal tissues cannot be evaluated, the obtained concentration is a mean value depending on the composition of the different samples being measured. In this case an imaging method that could give information both on the morphology and on the spatial distribution of boron concentration in the sample would be a fundamental support. In this paper, the results of the boron uptake analysis in the tumour and in the healthy samples taken from human livers after boron phenylalanine (BPA) infusion are shown; boron imaging was performed using neutron autoradiography.
Assuntos
Autorradiografia/métodos , Boro/farmacocinética , Neoplasias/metabolismo , Humanos , Metástase Neoplásica/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Nêutrons , Cintilografia , Distribuição TecidualRESUMO
A measurement of the helicity dependence of the total inclusive photoabsorption cross section on the deuteron was carried out at MAMI (Mainz) in the energy range 200
RESUMO
Helicity-dependent total photoabsorption cross sections on the deuteron have been measured for the first time at ELSA (Bonn) in the photon energy range from 815 to 1825 MeV. Circularly polarized tagged photons impinging on a longitudinally polarized LiD target have been used together with a highly efficient 4pi detector system. The data around 1 GeV are not compatible with predictions from existing multipole analyses. From the measured energy range an experimental contribution to the GDH integral on the neutron of [33.9 +/- 5.5(stat) +/- 4.5(syst)] microb is extracted.
RESUMO
The helicity dependence of the single pion photoproduction on the proton has been measured in the energy range from 200 to 450 MeV for the first time. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a frozen-spin target. The data obtained provide new information for multipole analyses of pion photoproduction and determine the main contributions to the Gerasimov-Drell-Hearn sum rule and the forward spin polarizability gamma(0).
RESUMO
The helicity dependence of the gamma-->p-->-->ppi(0) reaction has been measured for the first time in the photon-energy range from 550 to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. These data are predominantly sensitive to the D13(1520) resonance and are used to determine its helicity amplitudes.
RESUMO
To verify the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the first time experimentally, we measured the helicity dependent total photoabsorption cross section with circularly polarized real photons and longitudinally polarized nucleons in the photon energy range 0.68-1.82 GeV with the tagged photon facility at ELSA. The experiment was carried out with a 4pi detection system, a circularly polarized tagged photon beam, and a frozen spin polarized proton target. The contribution to the GDH sum rule in this photon energy range is [49.9+/-2.4(stat)+/-2.2(syst)] microb.
RESUMO
For the first time we checked the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the proton experimentally in the photon energy range from 0.2-2.9 GeV with the tagged photon facilities at MAMI (Mainz) and ELSA (Bonn). New data of the doubly polarized total cross section difference are presented in the energy range from 1.6 to 2.9 GeV. The contribution to the GDH integral from 0.2-2.9 GeV yields [254+/-5(stat)+/-12(syst)] microb with negative contributions in the Regge regime at photon energies above 2.1 GeV. This trend supports the validity of the GDH sum rule.