Dirk Flühs1, Andrea Flühs1, Melanie Ebenau2, Marion Eichmann3. 1. Universitätsklinikum Essen, Essen, Germany. 2. Universitätsklinikum Essen, Essen, Germany; Technische Universität Dortmund, Dortmund, Germany. 3. Technische Universität Dortmund, Dortmund, Germany.
Abstract
BACKGROUND: Dosimetric measurements in small radiation fields with large gradients, such as eye plaque dosimetry with β or low-energy photon emitters, require dosimetrically almost water-equivalent detectors with volumes of <1 mm(3) and linear responses over several orders of magnitude. Polyvinyltoluene-based scintillators fulfil these conditions. Hence, they are a standard for such applications. However, they show disadvantages with regard to certain material properties and their dosimetric behaviour towards low-energy photons. PURPOSE MATERIALS AND METHODS: Polyethylene naphthalate, recently recognized as a scintillator, offers chemical, physical and basic dosimetric properties superior to polyvinyltoluene. Its general applicability as a clinical dosimeter, however, has not been shown yet. To prove this applicability, extensive measurements at several clinical photon and electron radiation sources, ranging from ophthalmic plaques to a linear accelerator, were performed. RESULTS: For all radiation qualities under investigation, covering a wide range of dose rates, a linearity of the detector response to the dose was shown. CONCLUSION: Polyethylene naphthalate proved to be a suitable detector material for the dosimetry of ophthalmic plaques, including low-energy photon emitters and other small radiation fields. Due to superior properties, it has the potential to replace polyvinyltoluene as the standard scintillator for such applications.
BACKGROUND: Dosimetric measurements in small radiation fields with large gradients, such as eye plaque dosimetry with β or low-energy photon emitters, require dosimetrically almost water-equivalent detectors with volumes of <1 mm(3) and linear responses over several orders of magnitude. Polyvinyltoluene-based scintillators fulfil these conditions. Hence, they are a standard for such applications. However, they show disadvantages with regard to certain material properties and their dosimetric behaviour towards low-energy photons. PURPOSE MATERIALS AND METHODS:Polyethylene naphthalate, recently recognized as a scintillator, offers chemical, physical and basic dosimetric properties superior to polyvinyltoluene. Its general applicability as a clinical dosimeter, however, has not been shown yet. To prove this applicability, extensive measurements at several clinical photon and electron radiation sources, ranging from ophthalmic plaques to a linear accelerator, were performed. RESULTS: For all radiation qualities under investigation, covering a wide range of dose rates, a linearity of the detector response to the dose was shown. CONCLUSION:Polyethylene naphthalate proved to be a suitable detector material for the dosimetry of ophthalmic plaques, including low-energy photon emitters and other small radiation fields. Due to superior properties, it has the potential to replace polyvinyltoluene as the standard scintillator for such applications.
Authors: Louis Archambault; Tina M Briere; Falk Pönisch; Luc Beaulieu; Deborah A Kuban; Andrew Lee; Sam Beddar Journal: Int J Radiat Oncol Biol Phys Date: 2010-03-16 Impact factor: 7.038