title: MEASUREMENT OF SECONDARY NEUTRONS GENERATED DURING PROTON THERAPY.
abstract: Measurements described in this article were carried out with the aim of evaluating risks of the patient exposure to secondary neutrons during treatment at the Proton Therapy Centre Prague. The neutron spectral fluence was measured by means of the extended Bonner sphere spectrometer (EBS). The article presents secondary neutron spectral fluences obtained by the EBS with passive thermoluminescent detectors, i.e. pairs of6LiF and7LiF chips. Measurements were performed in two positions: the first one behind the Nylon 6 phantom, and the second one close to the range shifter to evaluate their contribution to the generation of neutrons. Both the Nylon 6 phantom and the range shifter were irradiated with a pencil beam of protons 4 mm in diameter and the energy of 200 MeV. The results are supplemented with the values of effective dose derived from neutron spectral fluences.
authors.affiliation: Czech Metrology Institute, Radiová 1a, Praha 10 102 00, Czech Republic zvykydal@cmi.cz.
authors.forename: Z
authors.initials: Z
authors.lastname: Vykydal
authors.affiliation: Proton Therapy Center Praha, Budínova 1a, Praha 8 180 00, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Andrlík
authors.affiliation: Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Břehová 7, Praha 1 115 19, Czech Republic.
authors.forename: H
authors.initials: H
authors.lastname: Bártová
authors.affiliation: Czech Metrology Institute, Radiová 1a, Praha 10 102 00, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Králík
authors.affiliation: Czech Metrology Institute, Radiová 1a, Praha 10 102 00, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Šolc
authors.affiliation: Proton Therapy Center Praha, Budínova 1a, Praha 8 180 00, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Vondráček
mesh_terms: D006801:Humans; D009502:Neutrons; D019047:Phantoms, Imaging; D061766:Proton Therapy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods