N Mojżeszek1, J Farah2, M Kłodowska1, O Ploc3, L Stolarczyk1, M P R Waligórski4, P Olko1. 1. Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Radzikowskiego 152, 31-342 Krakow, Poland. 2. Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Pôle Radioprotection de l'Homme, BP-17, 92260 Fontenay-aux-Roses, France; Hôpitaux Universitaires Paris-Sud, Pôle Imagerie et Médecine Nucléaire, Hôpital du Kremlin-Bicêtre, 78 Rue Général Leclerc, 94270 Le Kremlin-Bicêtre, France(1). Electronic address: jad.farah@hotmail.fr. 3. Nuclear Physics Institute, Academy of Sciences of the Czech Republic (NPI), CZ-250 68 Řež, Czech Republic. 4. Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Radzikowskiego 152, 31-342 Krakow, Poland; Centre od Oncology, Kraków Division, PL-31-115 Kraków, Poland.
Abstract
PURPOSE: To measure the environmental doses from stray neutrons in the vicinity of a solid slab phantom as a function of beam energy, field size and modulation width, using the proton pencil beam scanning (PBS) technique. METHOD: Measurements were carried out using two extended range WENDI-II rem-counters and three tissue equivalent proportional counters. Detectors were suitably placed at different distances around the RW3 slab phantom. Beam irradiation parameters were varied to cover the clinical ranges of proton beam energies (100-220MeV), field sizes ((2×2)-(20×20)cm2) and modulation widths (0-15cm). RESULTS: For pristine proton peak irradiations, large variations of neutron H∗(10)/D were observed with changes in beam energy and field size, while these were less dependent on modulation widths. H∗(10)/D for pristine proton pencil beams varied between 0.04μSvGy-1 at beam energy 100MeV and a (2×2)cm2 field at 2.25m distance and 90° angle with respect to the beam axis, and 72.3μSvGy-1 at beam energy 200MeV and a (20×20) cm2 field at 1m distance along the beam axis. CONCLUSIONS: The obtained results will be useful in benchmarking Monte Carlo calculations of proton radiotherapy in PBS mode and in estimating the exposure to stray radiation of the patient. Such estimates may be facilitated by the obtained best-fitted simple analytical formulae relating the stray neutron doses at points of interest with beam irradiation parameters.
PURPOSE: To measure the environmental doses from stray neutrons in the vicinity of a solid slab phantom as a function of beam energy, field size and modulation width, using the proton pencil beam scanning (PBS) technique. METHOD: Measurements were carried out using two extended range WENDI-II rem-counters and three tissue equivalent proportional counters. Detectors were suitably placed at different distances around the RW3 slab phantom. Beam irradiation parameters were varied to cover the clinical ranges of proton beam energies (100-220MeV), field sizes ((2×2)-(20×20)cm2) and modulation widths (0-15cm). RESULTS: For pristine proton peak irradiations, large variations of neutron H∗(10)/D were observed with changes in beam energy and field size, while these were less dependent on modulation widths. H∗(10)/D for pristine proton pencil beams varied between 0.04μSvGy-1 at beam energy 100MeV and a (2×2)cm2 field at 2.25m distance and 90° angle with respect to the beam axis, and 72.3μSvGy-1 at beam energy 200MeV and a (20×20) cm2 field at 1m distance along the beam axis. CONCLUSIONS: The obtained results will be useful in benchmarking Monte Carlo calculations of proton radiotherapy in PBS mode and in estimating the exposure to stray radiation of the patient. Such estimates may be facilitated by the obtained best-fitted simple analytical formulae relating the stray neutron doses at points of interest with beam irradiation parameters.
Authors: Vladimir Mares; Jad Farah; Marijke De Saint-Hubert; Szymon Domański; Carles Domingo; Martin Dommert; Magdalena Kłodowska; Katarzyna Krzempek; Michał Kuć; Immaculada Martínez-Rovira; Edyta Michaś; Natalia Mojżeszek; Łukasz Murawski; Ondrej Ploc; Maite Romero-Expósito; Marco Tisi; François Trompier; Olivier Van Hoey; Laurent Van Ryckeghem; Marek Wielunski; Roger M Harrison; Liliana Stolarczyk; Pawel Olko Journal: Front Oncol Date: 2022-07-14 Impact factor: 5.738
Authors: Olivier Van Hoey; Liliana Stolarczyk; Jan Lillhök; Linda Eliasson; Natalia Mojzeszek; Malgorzata Liszka; Ali Alkhiat; Vladimir Mares; François Trompier; Sebastian Trinkl; Immaculada Martínez-Rovira; Maite Romero-Expósito; Carles Domingo; Ondrej Ploc; Roger Harrison; Pawel Olko Journal: Front Oncol Date: 2022-09-08 Impact factor: 5.738