| 1. |
- Capala, J, et al.
(författare)
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Boron neutron capture therapy for glioblastoma multiforme : Clinical studies in Sweden
- 2003
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Ingår i: Journal of Neuro-Oncology. - 1573-7373. ; 62:1, s. 135-144
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Tidskriftsartikel (refereegranskat)abstract
- A boron neutron capture therapy (BNCT) facility has been constructed at Studsvik, Sweden. It includes two filter/moderator configurations. One of the resulting neutron beams has been optimized for clinical irradiations with a filter/moderator system that allows easy variation of the neutron spectrum from the thermal to the epithermal energy range. The other beam has been designed to produce a large uniform field of thermal neutrons for radio-biological research. Scientific operations of the Studsvik BNCT project are overseen by the Scientific Advisory Board comprised of representatives of major universities in Sweden. Furthermore, special task groups for clinical and preclinical studies have been formed to facilitate collaboration with academia. The clinical Phase II trials for glioblastoma are sponsored by the Swedish National Neuro-Oncology Group and, presently, involve a protocol for BNCT treatment of glioblastoma patients who have not received any therapy other than surgery. In this protocol, p-boronophenylalanine (BPA), administered as a 6-h intravenous infusion, is used as the boron delivery agent. As of January 2002, 17 patients were treated. The 6-h infusion of 900 mg BPA/kg body weight was shown to be safe and resulted in the average blood-boron concentration of 24 μg/g (range: 15-32 μg/g) at the time of irradiation (approximately 2-3 h post-infusion). Peak and average weighted radiation doses to the brain were in the ranges of 8.0-15.5 Gy(W) and 3.3-6.1 Gy(W), respectively. So far, no severe BNCT-related acute toxicities have been observed. Due to the short follow-up time, it is too early to evaluate the efficacy of these studies.
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| 2. |
- Persson, Bertil R, et al.
(författare)
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“Abscopal” Effect of Radiation Therapy Combined with Immune-Therapy Using IFN-γ Gene Transfected Syngeneic Tumor Cells, in Rats with Bilateral Implanted N29 Tumors
- 2011
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Ingår i: ISRN Immunology. - : Hindawi Limited. - 2090-5645 .- 2090-5653. ; 2011
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Tidskriftsartikel (refereegranskat)abstract
- The tumor growth rate response was studied on N29 rat glioma tumor cells subcutaneously implanted on both hind legs of Fischer-344 rats. At around 30 days after inoculation, RT was given with 60Co gamma radiation with 4 daily fractions of 5 Gy only to the right-lateral tumors. At days 26, 42, and 54 after inoculation, immunization was performed with irradiated syngeneic IFNγ-gene transfected cells. Tumor growth rate (TGR % per day) of the right-lateral irradiated tumor was significantly decreased (P<0.01) after RT alone and with the combination of RT and immunization. But immunization alone gave no significant decrease of the TGR but significantly increased time of survival. The TGR of the unirradiated left-lateral tumors was significantly decreased (P<0.02) only in the group of rats treated with RT alone. It is apparent that tumor cells killed by the radiation mediate suppression of tumor cells outside the target area. This effect is called the abscopal effect.
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| 3. |
- Persson, Bertil R, et al.
(författare)
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Radiation immunomodulatory gene tumor therapy of rats with intracerebral glioma tumors.
- 2010
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Ingår i: Radiation Research. - 0033-7587. ; 173:4, s. 433-440
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Tidskriftsartikel (refereegranskat)abstract
- Single-fraction radiation therapy with 5 or 15 Gy (60)Co gamma radiation was combined with intraperitoneal injections of syngeneic interferon gamma (IFN-gamma)-transfected cells in rats with intracerebral N29 or N32 glioma tumors at days 7, 21 and 35 after inoculation. For intracerebral N29 tumors, single-fraction radiation therapy with 5 or 15 Gy had no significant effect on the survival time. Immunization with IFN-gamma-transfected N29 cells significantly increased the survival time by 61%. Single-fraction radiation therapy with 5 Gy combined with immunization increased the survival time significantly by 87% and complete remissions by 75% while with 15 Gy the survival time increased 45% with 38% complete remissions. For intracerebral N32 tumors, single-fraction radiation therapy with 15 Gy increased the survival time significantly by 20%. Immunization by itself had no significant effect with IFN-gamma-transfected N32 cells, but combined with 15 Gy single-fraction radiation therapy it increased survival time significantly by 40%, although there were no complete remissions. Based on these findings, we suggest a new therapeutic regimen for malignant glioma using single-fraction radiation therapy with a target absorbed dose of the order of 5-10 Gy combined with clinically verified immunotherapy.
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| 4. |
- Persson, Bertil R, et al.
(författare)
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Survival of rats with N29 brain tumours after irradiation with 5 or 15 Gy and immunization with IFN-gamma secreting tumour cells
- 2008
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Ingår i: BioMedical Engineering and Informatics : New Development and the Future - Proceedings of the 1st International Conference on BioMedical Engineering and Informatics, BMEI 2008 - New Development and the Future - Proceedings of the 1st International Conference on BioMedical Engineering and Informatics, BMEI 2008. - 9780769531182 ; 2, s. 243-247
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Konferensbidrag (refereegranskat)abstract
- Intra cerebral tumours were inoculated into the brain of Fischer-344 syngeneic rats. After one week they were treated with either 5 or 15 Gy of Co-60-gamma radiation. The first immunization was given 1 hour before the radiation treatment and then two more times with 14-day intervals. Immunization was performed with 3 x 10(6) radiation sterilized IFN-gamma secreting tumour cells (N29) injected intraperitoneally. Neither radiation therapy with 5 or 15 Gy nor immunization with N29 cells alone had any significant effect on the length of survival of N29 tumour bearing rats. But radiation therapy with 5 Gy combined with immunization with IFN-gamma secreting syngeneic N29 cells resulted in 63 % complete remissions and significantly (p < 0.05) increased survival for the tumour bearing rats. Corresponding combination with 15 Gy RT resulted in 50% complete remissions. There is a possibility of a synergistic effect by optimal combination of radiation therapy and immunization.
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| 5. |
- Munck af Rosenschöld, Per, et al.
(författare)
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Current status of dosimetry at the boron neutron capture therapy facility at Studsvik, Sweden
- 2002
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Ingår i: Research and Development in Neutron Capture Therapy. - 9788832329094 ; , s. 437-441
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Konferensbidrag (refereegranskat)abstract
- The beam was successfully characterized in air and in phantom using various radiation dosimeter:,. The determination of the thermal neutron and photon components of the mixed beam in phantom can be determined with acceptable uncertainties, while the uncertainty of the high-energy neutron component is considerable but of limited clinical significance. The beam intensity is sufficiently high for reasonably short treatment times. A novel approach to in-vivo dosimetry and quality assurance of treatment time in terms of monitor units was introduced in order to comply with national regulations regarding radiation therapy.
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| 6. |
- 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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