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Neutron Capture Therapy (neutron + capture_therapy)
Kinds of Neutron Capture Therapy Selected AbstractsEffect of Boron Neutron Capture Therapy for Melanotic and Amelanotic Melanoma Transplanted into Mouse BrainPIGMENT CELL & MELANOMA RESEARCH, Issue 1 2002Masaki Iwakura In order to develop a protocol to treat brain metastatic melanoma using our 10B- p -boronophenylalanine (BPA) boron neutron capture therapy (BNCT), we initiated the following studies (i), Comparative analyses of boron biodistribution between melanoma proliferating in the brain and skin among melanotic and amelanotic types, and (ii) Therapeutic evaluation of BPA,BNCT for brain melanoma models of both types, using survival times. Our present data have revealed that boron concentration in melanoma proliferating in the brain, the major prerequisite for successful BNCT, showed a positive correlation to melanin synthesizing activity in the same way as melanoma proliferating in skin. Further, the boron concentration ratio of melanoma to normal surrounding tissue for brain melanoma models was considerably higher than that for subcutaneous (s.c.) ones because of the existence of the blood,brain barrier (BBB). Additionally, from analyses of median and mean survival times following BNCT using low, middle, and high neutron doses, the therapeutic effect of BNCT for the amelanotic A1059 melanoma appeared at first glance to be higher than that for the highly BPA attracting and highly relative biological effect equivalent dose obtaining B15b melanoma. As the survival time was dependent on both regression and regrowth curves, and because the brain melanoma model in small animals made it difficult to evaluate these curves separately, we further examined the in vivo growth curve of both types of melanomas following implantation in s.c. tissue. The melanotic B15b melanoma was indeed found to possess much higher growth rate as compared with that of the amelanotic A1059 melanoma. The significance of boron biodistribution studies and BNCT survival curve analyses in forming an effective clinical protocol for individual human cases of melanoma brain metastasis is discussed. [source] Boron Neutron Capture Therapy for glioblastoma multiforme: advantage of prolonged infusion of BPA-fACTA NEUROLOGICA SCANDINAVICA, Issue 1 2010K. Sköld Sköld K, H-Stenstam B, Diaz AZ, Giusti V, Pellettieri L, Hopewell JW. Boron Neutron Capture Therapy for glioblastoma multiforme: advantage of prolonged infusion of BPA-f. Acta Neurol Scand: 2010: 122: 58,62. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objectives,,, To assess possible improved efficacy of Boron Neutron Capture Therapy (BNCT) for glioblastoma multiforme (GBM) using prolonged infusion and a correspondingly higher dose of l-boronophenylalanine, as the fructose complex (BPA-f). Materials and methods,,, The benefit of prolonged infusion was analyzed by comparing the results from a Phase II study using 6 h infusion of BPA-f with those obtained from a Phase I/II study using 2 h of infusion. Median survival time (MST) from diagnosis, patient baseline characteristics, salvage treatment and severe adverse events were considered in the comparison. Results,,, MST increased significantly, from 12.8 (95% confidence interval or CI: 10.3,14.0) months with 2 h infusion to 17.7 (95% CI: 13.6,19.9) months with 6 h of infusion. The fraction of patients with WHO grade 3,4 adverse events was similar in the two studies at 13% and 14%, respectively. Conclusion,,, Prolonged infusion was found to be beneficial for the efficacy of BNCT and it is suggested that 6 h infusion of BPA-f should be used in future trials of BNCT for GBM. BNCT, which is a single-day treatment with mild side effects, should be assessed in a controlled trial, as an alternative to 30 daily fractions of conventional fractionated photon therapy over a period of 6 weeks. [source] Synthesis of Dodecaborate-Conjugated Cholesterols for Efficient Boron Delivery in Neutron Capture Therapy.CHEMINFORM, Issue 30 2007Hiroyuki Nakamura Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis and radioiodination of 7-(3,-ammoniopropyl)-7,8-dicarba- nido -undecaborate(-1), (ANC)JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2004Senait Ghirmai Abstract Derivatives of nido -carborate have potential use in tumour targeting as hydrophilic boron-rich compounds for boron neutron capture therapy (BNCT) and as pendant groups for attachment of radiohalogens to tumour-seeking molecules. For this purpose, functionalized derivatives of nido -carborates that can be conjugated to biomolecules should be synthesized and evaluated. In this study, racemic 1, 7-(3,-ammoniopropyl)-7,8-dicarba- nido -undecaborate(-1) (acronym ANC) was obtained by degradation of the corresponding aminopropyl- o -carborane, which was synthesized in three steps from 1- tert -butyldimethylsilyl-2-(3-bromopropyl)- o -carborane, with sodium hydroxide in absolute ethanol. The racemate 1 was radioiodinated (125I) using the Chloramine-T method. Radio-TLC results showed that radiolabelling with 125I was achieved in a yield greater than 95%. Copyright © 2004 John Wiley & Sons, Ltd. [source] In vivo imaging of the neutron capture therapy agent BSH in mice using 10B MRIMAGNETIC RESONANCE IN MEDICINE, Issue 1 2001Peter Bendel Abstract Boron neutron capture therapy (BNCT) is an experimental cancer treatment modality requiring the targeting of 10B-enriched compounds to the tumor, which is then irradiated by low-energy neutrons. One of the boron-containing compounds used for this purpose is the mercaptoborane Na2B12H11SH (BSH). The first in vivo MR images of 10B-enriched BSH are presented here. BSH, injected into the tail vein of mice with implanted M2R melanoma xenografts, was imaged using 3D gradient echo 10B MRI. 10B NMR spectroscopy, localized mainly to the tumor by virtue of the use of a small surface coil, was applied to measure the T1 (2.9 ± 0.3 ms) and T2 (1.75 ± 0.25 ms) values of the 10B signal. The MRI experiments detected levels of about 20 ppm (,g boron / g tissue) at 6 × 6 × 6 mm spatial resolution in a total scan time of 16 min. Magn Reson Med 46:13,17, 2001. © 2001 Wiley-Liss, Inc. [source] Biomedical applications of 10B and 11B NMRNMR IN BIOMEDICINE, Issue 2 2005Peter Bendel Abstract This review focuses mainly on the detection and investigation of molecules used for boron neutron capture therapy (BNCT) by 10B and 11B NMR. In this binary radiation treatment, boron-containing molecules (also called ,BNCT agents') enriched in the 10B isotope, are targeted to the tumor, and irradiated with thermal or epithermal neutrons. Capture of these neutrons by 10B nuclei generates cell-damaging radiation, confined to single cell dimensions. NMR research efforts have primarily been applied in two directions: first, to investigate the metabolism and pharmaco-kinetics of BNCT agents in-vivo, and second, to use localized NMR spectroscopy and/or MRI for non-invasive mapping of the administered molecules in treated animals or patients. While the first goal can be pursued using 11B NMR for natural-abundance samples (80% 11B / 20% 10B), molecules used in the actual treatment are >,95% enriched in 10B, and must therefore be detected by 10B NMR. Both 10B (spin 3) and 11B (spin 3/2) are quadrupolar nuclei, and their typical relaxation times, in common BNCT agents in biological environments, are rather short. This poses some technical challenges, particularly for MRI, which will be reviewed, along with possible solutions. The first attempts at 11B NMR and MRI detection of BNCT agents in biological tissue were conducted over a decade ago. Since then, results from 11B MRI in laboratory animals and in humans have been reported, and 11B NMR spectroscopy provided interesting and unique information about the metabolism of some BNCT agents in cultured cells. 10B NMR was applied either ,indirectly' (in double-resonance experiments involving coupled protons), but also by direct 10B MRI in mice. However, no results involving the NMR detection of 10B-enriched compounds in treated patients have been reported yet. Copyright © 2005 John Wiley & Sons, Ltd. [source] Effect of Boron Neutron Capture Therapy for Melanotic and Amelanotic Melanoma Transplanted into Mouse BrainPIGMENT CELL & MELANOMA RESEARCH, Issue 1 2002Masaki Iwakura In order to develop a protocol to treat brain metastatic melanoma using our 10B- p -boronophenylalanine (BPA) boron neutron capture therapy (BNCT), we initiated the following studies (i), Comparative analyses of boron biodistribution between melanoma proliferating in the brain and skin among melanotic and amelanotic types, and (ii) Therapeutic evaluation of BPA,BNCT for brain melanoma models of both types, using survival times. Our present data have revealed that boron concentration in melanoma proliferating in the brain, the major prerequisite for successful BNCT, showed a positive correlation to melanin synthesizing activity in the same way as melanoma proliferating in skin. Further, the boron concentration ratio of melanoma to normal surrounding tissue for brain melanoma models was considerably higher than that for subcutaneous (s.c.) ones because of the existence of the blood,brain barrier (BBB). Additionally, from analyses of median and mean survival times following BNCT using low, middle, and high neutron doses, the therapeutic effect of BNCT for the amelanotic A1059 melanoma appeared at first glance to be higher than that for the highly BPA attracting and highly relative biological effect equivalent dose obtaining B15b melanoma. As the survival time was dependent on both regression and regrowth curves, and because the brain melanoma model in small animals made it difficult to evaluate these curves separately, we further examined the in vivo growth curve of both types of melanomas following implantation in s.c. tissue. The melanotic B15b melanoma was indeed found to possess much higher growth rate as compared with that of the amelanotic A1059 melanoma. The significance of boron biodistribution studies and BNCT survival curve analyses in forming an effective clinical protocol for individual human cases of melanoma brain metastasis is discussed. [source] Analyses of Thick Lithium Coatings Deposited by Sputter-Evaporation and Exposed to AirPLASMA PROCESSES AND POLYMERS, Issue S1 2009C. Rigaux Abstract Lithium coatings on various substrates have numerous applications: Boron neutron capture therapy, neutron activation analysis, super-conducting tokamak etc. Traditionally these coatings are produced by well-known techniques such as electrochemistry and evaporation. In this work, we investigated a new method based on sputter-evaporation, which enables thick coatings (>10,µm) to be built on various substrates within a short timeframe. In order to minimize the process time, evaporation techniques can be used but the coating quality suffers. Moreover, it is well known that the use of DC magnetron sputtering results in the deposition of good quality coatings (smoothness, density, adhesion); however, the deposition rate is low. The rationale of this work is to combine these two techniques, yielding a sputter-evaporation process that possesses the advantages of each separate technique. Li is placed in a stainless steel crucible (cathode), and heated by the plasma generated by a magnetron discharge. The Li temperature is measured by a thermocouple welded onto the cathode and measured at different plasma power densities. The deposition rate of lithium is measured using a quartz balance and by profilometry, at several temperatures (from 0 to 580,°C). Li samples were depth-profiled with the resonant nuclear reaction 7Li(p,,)7. In addition to the concentration, certain characteristics like the density and the chemical reactivity of layers, are also important. Thus we have studied the evolution of the density with time, estimated by weight and profilometry measurements, and the change in morphology, by cross-sectional scanning electron microscopy (SEM), of samples exposed to air at room temperature. The evolution of the film compounds have also been determined by X-ray powder diffraction. These physical properties have been investigated for various bias substrates during deposition. [source] Novel types of boronated chlorin e6 conjugates via ,click chemistry'APPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2009Vladimir I. Bregadze Abstract Conjugates of chlorin e6 with closo -dodecaborate and cobalt bis(dicarbollide) anions were synthesized for the first time in high yields using the advanced ,click' methodology. In vitro study on A549 human lung adenocarcinoma cells revealed that the synthesized boronated conjugates are able to penetrate and accumulate in cancer cells, but their intracellular concentration is not sufficient for effective photodynamic and boron neutron capture therapy of cancer. Copyright © 2009 John Wiley & Sons, Ltd. [source] Synthesis of a novel boronated 1-aminocyclobutanecarboxylic acid as a potential boron neutron capture therapy agent,APPLIED ORGANOMETALLIC CHEMISTRY, Issue 6-7 2003George W. Kabalka Abstract A boronated aminocyclobutanecarboxylic acid was synthesized for potential use in neutron capture therapy. The synthesis involves the preparation of hydroxymethylcyclobutanone ketal, which is then converted to an amino acid using Bucherer,Strecker methodology. The molecule is modeled after the unnatural amino acid, 1-aminocyclobutanecarboxylic acid, which has demonstrated high uptake in brain tumors. Copyright © 2003 John Wiley & Sons, Ltd. [source] | |||||||||||||