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- Capala, Jacek, et al.
(författare)
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Clinical BNCT studies in Sweden
- 2002
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Ingår i: Research and development in neutron capture therapy. - : Monduzzi Editore Print. ; , s. 1101-
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Dahlström Wester, Maria, et al.
(författare)
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Accumulation of 10B in human synovial sarcoma cells in vitro for possible use in BNCT
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Synovial sarcoma is a distinct tumour with unique promise for targeted therapy. Due to the location and characteristics, boron neutron capture therapy (BNCT) might be an interesting alternative treatment regimen. The binary method utilizes the ionizing effects of high energy short-ranged fission particles produced after the capturing of neutrons by stable 10B. This study reports results regarding the accumulation of 10B administered as boronophenylalanine (BPA) in a human synovial sarcoma cell line (4SS) in vitro. 4SS cells were incubated in BPAcontaining cell culture medium and cell-associated boron was analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results show that 4SS cells accumulate boron in a clinical relevant concentration range. Further investigations may state the potential of BNCT as a treatment modality for synovial sarcomas and explore the possibilities of a directed delivery of boron-containing substances to receptors specifically expressed in this malignancy.
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| 7. |
- Dahlström Wester, Maria, et al.
(författare)
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Accumulation of boron in human malignant glioma cells in vitro is cell type dependent
- 2004
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Ingår i: Journal of Neuro-Oncology. - 0167-594X .- 1573-7373. ; 68:3, s. 199-205
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Tidskriftsartikel (refereegranskat)abstract
- It has been shown that human malignant glioma tumours consist of several subpopulations of tumour cells. Due to heterogeneity and different degrees of vascularisation cell subpopulations possess varying resistance to chemo- or radiation therapy. Therefore, therapy is dependent on the ability to specifically target a tumour cell. Boron neutron capture therapy (BNCT) is a bimodal method, in radiation therapy, taking advantage of the ability of the stable isotope boron-10 to capture neutrons. It results in disintegration products depositing large amounts of energy within a short length, approximately one cell diameter. Thereby, selective irradiation of a target cell may be accomplished if a sufficient amount of boron has been accumulated and hence the cell-associated boron concentration is of critical importance. The accumulation of boron, boronophenylalanine (BPA), was investigated in two human glioma cell subpopulations and a human fibroblast cell line in vitro. The cells were incubated at low boron concentrations (0-5 microg B/ml). Oil filtration was then used for separation of extracellular and cell-associated boron. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used for boron determination. Significant (P < 0.05) differences in accumulation ratio (relation between cell-associated and extracellular boron concentration) between human malignant glioma cell lines were found. Human fibroblasts, used to represent normal cells, showed a growth-dependent uptake and a lower accumulation ratio than the glioma cells. Our findings indicate that BPA concentration, incubation time and differences in boron uptake between cell subpopulations should be considered in BNCT.
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| 8. |
- Henriksson, Roger, et al.
(författare)
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Boron neutron capture therapy (BNCT) for glioblastoma multiforme : a phase II study evaluating a prolonged high-dose of boronophenylalanine (BPA)
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 88:2, s. 183-91
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: To evaluate the efficacy and safety of boron neutron capture therapy (BNCT) for glioblastoma multiforme (GBM) using a novel protocol for the boronophenylalanine-fructose (BPA-F) infusion. PATIENT AND METHODS: This phase II study included 30 patients, 26-69 years old, with a good performance status of which 27 have undergone debulking surgery. BPA-F (900 mg BPA/kg body weight) was given i.v. over 6h. Neutron irradiation started 2h after the completion of the infusion. Follow-up reports were monitored by an independent clinical research institute. RESULTS: The boron-blood concentration during irradiation was 15.2-33.7 microg/g. The average weighted absorbed dose to normal brain was 3.2-6.1 Gy (W). The minimum dose to the tumour volume ranged from 15.4 to 54.3 Gy (W). Seven patients suffered from seizures, 8 from skin/mucous problem, 5 patients were stricken by thromboembolism and 4 from abdominal disturbances in close relation to BNCT. Four patients displayed 9 episodes of grade 3-4 events (WHO). At the time for follow-up, minimum ten months, 23 out of the 29 evaluable patients were dead. The median time from BNCT treatment to tumour progression was 5.8 months and the median survival time after BNCT was 14.2 months. Following progression, 13 patients were given temozolomide, two patients were re-irradiated, and two were re-operated. Patients treated with temozolomide lived considerably longer (17.7 vs. 11.6 months). The quality of life analysis demonstrated a progressive deterioration after BNCT. CONCLUSION: Although, the efficacy of BNCT in the present protocol seems to be comparable with conventional radiotherapy and the treatment time is shorter, the observed side effects and the requirement of complex infrastructure and higher resources emphasize the need of further phase I and II studies, especially directed to improve the accumulation of (10)B in tumour cells.
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- Kullberg, Erika Bohl, et al.
(författare)
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EGF-receptor targeted liposomes with boronated acridine : growth inhibition of cultured glioma cells after neutron irradiation
- 2005
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 81:8, s. 621-629
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To study survival of cultured U-343MGaCl 2:6 glioma cells after incubation with boron-containing liposomes targeting the epidermal growth factor receptor following neutron irradiation. MATERIALS AND METHODS: Epidermal growth factor-tagged liposomes were loaded with water-soluble boronated acridine developed for boron neutron capture therapy, (BNCT). Cellular uptake and distribution were studied. Further, cells were placed at 3 cm depth in a phantom and exposed to an epithermal neutron beam to study clonogenic cell survival. RESULTS: The cellular uptake of boron reached 90 ppm and it was determined by subcellular fractionation that most of the cell-associated boron was located outside of the nucleus. For clonogenic survival, the cells were incubated with epidermal growth factor receptor-targeted liposomes for 4 hours resulting in a cellular concentration of 55 ppm boron (11 ppm 10B). At a fluence of 3 x 10(12) neutrons/cm2 the cell killing effect of the boron-containing epidermal growth factor-liposomes was about ten times higher than for neutrons only. Furthermore, theoretical calculation of the survival by enriched compound (55 ppm 10B), using the parameters from non-enriched compound (11 ppm 10B), shows that the killing effect in this case would be approximately five orders of magnitude higher than for neutrons only. CONCLUSION: The results in this study show that epidermal growth factor-receptor targeted liposomes are suitable as tumor-cell delivery agents of boron for BNCT and support further studies to demonstrate their effectiveness in vivo.
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| 10. |
- Munck af Rosenschöld, Per, et al.
(författare)
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Quality assurance of patient dosimetry in boron neutron capture therapy
- 2004
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 43:4, s. 404-411
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Tidskriftsartikel (refereegranskat)abstract
- The verification of the correctness of planned and executed treatments is imperative for safety in radiotherapy. The purpose of the present work is to describe and evaluate the quality assurance (QA) procedures for patient dosimetry implemented at the boron neutron capture therapy (BNCT) facility at Studsvik, Sweden. The dosimetric complexity of the mixed neutron-photon field during BNCT suggests a careful verification of routine procedures, specifically the treatment planning calculations. In the present study, two methods for QA of patient dosimetry are presented. The first is executed prior to radiotherapy and involves an independent check of the planned absorbed dose to be delivered to a point in the patient for each treatment field. The second QA procedure involves in vivo dosimetry measurements using posttreatment activation analysis. Absorbed dose conversion factors taking the difference in material composition and geometry of the patient and the PMMA phantom used for reference dosimetry were determined using the Monte Carlo method. The agreement of the QA procedure prior to radiotherapy reveals an acceptably small deviation for 60 treatment fields of ±4.2% (1 SD), while the in vivo dosimetry method presented may benefit from improvements, as the deviations observed were quite substantial (±12%, 1 SD), and were unlikely to be due to actual errors in the clinical dosimetry.
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| 11. |
- Orlova, Anna
(författare)
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Indirect Radiohalogenation of Targeting Proteins : Labelling Chemistry and Biological Characterisation
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In about half of all newly diagnosed cancer cases, conventional treatment is not adequately curative, mainly due to the failure of conventional techniques to find and kill residual cells and metastases, which might consist of only a few malignant cells, without causing unacceptable complications to healthy tissue. To solve the problem a more selective delivery of cytotoxic substances to tumour cells is needed. The approach applied here is called ‘tumour targeting’ and implies the use of biomolecules that recognise specific molecular structures on the malignant cell surface. Such molecules are then used for a selective transport of toxic agents to the cancer cells. The use of radionuclides as cytotoxic substances has a number of advantages: 1) radiation does not cause severe resistance; 2) there is a cross-fire effect and 3) smaller amounts of nuclides are required than other cytotoxic substances to cause the same damage. Such an approach is called radionuclide tumour therapy. Several factors are important for the success of radionuclide therapy, such as the pharmacokinetics of the radiolabelled substance and its radiocatabolites, as well as the physical and chemical properties of the radiolabel used.Nuclear properties of the label should be consistent with the problem to be solved: primary diagnostics; quantification of pharmacokinetics and dose planning; or therapy. From this point of view, radiohalogens are an attractive group of radiolabels. Halogens have nuclides with a variety of physical properties while the chemical and biological properties of halogens are very similar. The same labelling procedures can be used for all heavy halogens, i.e. bromine, iodine and astatine. It has been demonstrated that the biodistribution of proteins labelled with different heavy halogens is quite similar. The main goal of the study was to develop protein radiohalogenation methods that provide a stable halogen-protein bond, convenient labelling chemistry that preserves the binding properties of proteins, long intracellular retention of radioactivity in targeted cells and quick release of radiohalogenated catabolites from the blood circulation. Radiohalogenation of proteins using indirect methods was studied, including optimisation of labelling chemistry and biological characterisation of some labelled conjugates. Two groups for indirect radiohalogenation were used, representing two different labelling principles: activated ester of benzoic acid (1) and the derivative of closo-dodecaborate anion (2). The non-phenolic linker (1) as well as the borate-halogen moiety (2) probably prevent dehalogenation. The negative charge of the potential catabolic products of (2) might trap radiohalogens intracellularly.
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