TI detectors in BNCT dosimetry

Carita Aschan, Mika Toivonen, Tiina Seppälä, Petri Kotiluoto, Iiro Auterinen, Tom Seren, F. Stecher-Rasmussen, Sauli Savolainen

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional

Abstract

The main detectors for characterising and controlling of BNCT beams are activation foils and paired ionisation chambers. Thermoluminescent (TL) dosimeters are also of interest because of their following advanta: i) small physical size, ii) need for high voltage or cables, i.e. stand alone character, and iii) suitability for large scale measurements; with TL dosimeters it is possible to measure depth dose curves and profiles at the same time, with one irradiation. Also, TL dosimeters may be possible detectors for in vivo use. At the Finnish BNCT facility, a TL detector MTS-Ns of TLD Niewiadomski & Co. (Krakow, Poland) with an ultra-thin active Lif:Mg,Ti layer for small self-shielding of thermal neutrons was selected for use as a neutron sensitive dosimeter. A TL detector MCP-7s (7Lif:Mg,Cu,P) of the same manufacturer was used for gamma detection because of its high sensitivity to gamma radiation compared to that to high LET radiation. The gamma dose and neutron fluence distributions have been measured in PMMA, water and brain substitute liquid phantoms at the BNCT beam. Gamma dose and neutron fluence profiles measured with TL detectors correlate with those calculated using DORT (Two Dimensional Discrete Ordinates Transport Code) and measured with ionisation chambers. MTS-Ns TL detectors were found to measure accurately (8 %, 1 S.D.) the relative neutron fluence, and therfore to be a useful addition to the activation foils in bnct neutron dosimetry. Due to the high uncertainty of the thermal neutron sensitivity of the MCP-7s TL detectors, the absorbed gamma doses can be measured with MCP-7s detectors within 20% in the mixed neutron-gamma field of BNCT. The treatments of glioma patients at the Finnish BNCT facility will start in the spring 1999. The doses to the target volume and sensitive organs, i.e. brain, will be calculated individually in the dose planning. Since it is also necessary to monitor the absorbed doses to the head and to the body, in vivo dosimeters are used. For clinical practice, when verifying the absorbed doses in vivo the used TL and activation foil dosimeters must be placed on the skin of the patient of in accessible cavities. The TL detector MCP-7s will be used in in vivo gamma dosimetry. The correlations for the thermal neutron sensitivity of the MCP-7s TL detectors will be made based on the neutron fluence measured with activation foils. The accuracy of approximately 10% can be achieved in those measurement points, in which thermal neutron fluence is negligible and, therefore, no correlation for thermal neutron sensitivity is required. This applies to those measurement points in the body, i.e. total body dose.
Original languageEnglish
Title of host publicationCurrent status of neutron capture therapy
Place of PublicationVienna
PublisherInternational Atomic Energy Agency IAEA
ChapterAnnex 5
Pages165-174
Publication statusPublished - 2001
MoE publication typeD2 Article in professional manuals or guides or professional information systems or text book material

Fingerprint

dosimeters
dosage
detectors
thermal neutrons
neutrons
fluence
foils
activation
ionization chambers
brain
Poland
profiles
organs
cables
shielding
planning
high voltages
gamma rays
substitutes
cavities

Cite this

Aschan, C., Toivonen, M., Seppälä, T., Kotiluoto, P., Auterinen, I., Seren, T., ... Savolainen, S. (2001). TI detectors in BNCT dosimetry. In Current status of neutron capture therapy (pp. 165-174). Vienna: International Atomic Energy Agency IAEA.
Aschan, Carita ; Toivonen, Mika ; Seppälä, Tiina ; Kotiluoto, Petri ; Auterinen, Iiro ; Seren, Tom ; Stecher-Rasmussen, F. ; Savolainen, Sauli. / TI detectors in BNCT dosimetry. Current status of neutron capture therapy. Vienna : International Atomic Energy Agency IAEA, 2001. pp. 165-174
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title = "TI detectors in BNCT dosimetry",
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author = "Carita Aschan and Mika Toivonen and Tiina Sepp{\"a}l{\"a} and Petri Kotiluoto and Iiro Auterinen and Tom Seren and F. Stecher-Rasmussen and Sauli Savolainen",
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Aschan, C, Toivonen, M, Seppälä, T, Kotiluoto, P, Auterinen, I, Seren, T, Stecher-Rasmussen, F & Savolainen, S 2001, TI detectors in BNCT dosimetry. in Current status of neutron capture therapy. International Atomic Energy Agency IAEA, Vienna, pp. 165-174.

TI detectors in BNCT dosimetry. / Aschan, Carita; Toivonen, Mika; Seppälä, Tiina; Kotiluoto, Petri; Auterinen, Iiro; Seren, Tom; Stecher-Rasmussen, F.; Savolainen, Sauli.

Current status of neutron capture therapy. Vienna : International Atomic Energy Agency IAEA, 2001. p. 165-174.

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional

TY - CHAP

T1 - TI detectors in BNCT dosimetry

AU - Aschan, Carita

AU - Toivonen, Mika

AU - Seppälä, Tiina

AU - Kotiluoto, Petri

AU - Auterinen, Iiro

AU - Seren, Tom

AU - Stecher-Rasmussen, F.

AU - Savolainen, Sauli

PY - 2001

Y1 - 2001

N2 - The main detectors for characterising and controlling of BNCT beams are activation foils and paired ionisation chambers. Thermoluminescent (TL) dosimeters are also of interest because of their following advanta: i) small physical size, ii) need for high voltage or cables, i.e. stand alone character, and iii) suitability for large scale measurements; with TL dosimeters it is possible to measure depth dose curves and profiles at the same time, with one irradiation. Also, TL dosimeters may be possible detectors for in vivo use. At the Finnish BNCT facility, a TL detector MTS-Ns of TLD Niewiadomski & Co. (Krakow, Poland) with an ultra-thin active Lif:Mg,Ti layer for small self-shielding of thermal neutrons was selected for use as a neutron sensitive dosimeter. A TL detector MCP-7s (7Lif:Mg,Cu,P) of the same manufacturer was used for gamma detection because of its high sensitivity to gamma radiation compared to that to high LET radiation. The gamma dose and neutron fluence distributions have been measured in PMMA, water and brain substitute liquid phantoms at the BNCT beam. Gamma dose and neutron fluence profiles measured with TL detectors correlate with those calculated using DORT (Two Dimensional Discrete Ordinates Transport Code) and measured with ionisation chambers. MTS-Ns TL detectors were found to measure accurately (8 %, 1 S.D.) the relative neutron fluence, and therfore to be a useful addition to the activation foils in bnct neutron dosimetry. Due to the high uncertainty of the thermal neutron sensitivity of the MCP-7s TL detectors, the absorbed gamma doses can be measured with MCP-7s detectors within 20% in the mixed neutron-gamma field of BNCT. The treatments of glioma patients at the Finnish BNCT facility will start in the spring 1999. The doses to the target volume and sensitive organs, i.e. brain, will be calculated individually in the dose planning. Since it is also necessary to monitor the absorbed doses to the head and to the body, in vivo dosimeters are used. For clinical practice, when verifying the absorbed doses in vivo the used TL and activation foil dosimeters must be placed on the skin of the patient of in accessible cavities. The TL detector MCP-7s will be used in in vivo gamma dosimetry. The correlations for the thermal neutron sensitivity of the MCP-7s TL detectors will be made based on the neutron fluence measured with activation foils. The accuracy of approximately 10% can be achieved in those measurement points, in which thermal neutron fluence is negligible and, therefore, no correlation for thermal neutron sensitivity is required. This applies to those measurement points in the body, i.e. total body dose.

AB - The main detectors for characterising and controlling of BNCT beams are activation foils and paired ionisation chambers. Thermoluminescent (TL) dosimeters are also of interest because of their following advanta: i) small physical size, ii) need for high voltage or cables, i.e. stand alone character, and iii) suitability for large scale measurements; with TL dosimeters it is possible to measure depth dose curves and profiles at the same time, with one irradiation. Also, TL dosimeters may be possible detectors for in vivo use. At the Finnish BNCT facility, a TL detector MTS-Ns of TLD Niewiadomski & Co. (Krakow, Poland) with an ultra-thin active Lif:Mg,Ti layer for small self-shielding of thermal neutrons was selected for use as a neutron sensitive dosimeter. A TL detector MCP-7s (7Lif:Mg,Cu,P) of the same manufacturer was used for gamma detection because of its high sensitivity to gamma radiation compared to that to high LET radiation. The gamma dose and neutron fluence distributions have been measured in PMMA, water and brain substitute liquid phantoms at the BNCT beam. Gamma dose and neutron fluence profiles measured with TL detectors correlate with those calculated using DORT (Two Dimensional Discrete Ordinates Transport Code) and measured with ionisation chambers. MTS-Ns TL detectors were found to measure accurately (8 %, 1 S.D.) the relative neutron fluence, and therfore to be a useful addition to the activation foils in bnct neutron dosimetry. Due to the high uncertainty of the thermal neutron sensitivity of the MCP-7s TL detectors, the absorbed gamma doses can be measured with MCP-7s detectors within 20% in the mixed neutron-gamma field of BNCT. The treatments of glioma patients at the Finnish BNCT facility will start in the spring 1999. The doses to the target volume and sensitive organs, i.e. brain, will be calculated individually in the dose planning. Since it is also necessary to monitor the absorbed doses to the head and to the body, in vivo dosimeters are used. For clinical practice, when verifying the absorbed doses in vivo the used TL and activation foil dosimeters must be placed on the skin of the patient of in accessible cavities. The TL detector MCP-7s will be used in in vivo gamma dosimetry. The correlations for the thermal neutron sensitivity of the MCP-7s TL detectors will be made based on the neutron fluence measured with activation foils. The accuracy of approximately 10% can be achieved in those measurement points, in which thermal neutron fluence is negligible and, therefore, no correlation for thermal neutron sensitivity is required. This applies to those measurement points in the body, i.e. total body dose.

M3 - Chapter or book article

SP - 165

EP - 174

BT - Current status of neutron capture therapy

PB - International Atomic Energy Agency IAEA

CY - Vienna

ER -

Aschan C, Toivonen M, Seppälä T, Kotiluoto P, Auterinen I, Seren T et al. TI detectors in BNCT dosimetry. In Current status of neutron capture therapy. Vienna: International Atomic Energy Agency IAEA. 2001. p. 165-174