Naslov
Measurement of stray radiation in scanning proton radiotherapy- Summary of the EURADOS WG 9 intercomparison results with passive and active dosimetry systems

Autori
Knežević, Željka ; Stolarczyk, Liliana

Kolaboracija
EURADOS WG9

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, pp prezentacija, znanstveni

Izvornik
Proceedings of the 14th International Workshop on Ionizing Radiation Monitoring / Takayoshi, Yamamoto - Ōarai : Chiyoda Technol Corporation (CTC), 2019, 41-47

Skup
14th International Workshop on Ionizing Radiation Monitoring

Mjesto i datum
Ōarai, Japan, 08.12.2018. - 09.12.2018

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
scanning proton radiotherapy ; stray radiation ; passive detectors ; active detectors ; EURADOS

Sažetak
Proton beam therapy has advantages in comparison to conventional photon radiotherapy due to the physical properties of proton beams. However, the interactions of protons with matter result in the production of secondary radiation, comprised mostly of neutrons and gamma radiation. This component may lead to unwanted out-of-field doses deposited distantly from the target volume and consequently an increased probability of late effects such as secondary cancers. The EURADOS Working Group 9 (Radiation dosimetry in radiotherapy) Sub Group 2 (Hadron therapy) performed comprehensive measurements of out-of-field neutron and photon doses inside a water phantom irradiated in the IBA (230 MeV) active-scanning proton beam therapy facility in Trento, Italy. 3-D mapping of out-of-field doses generated by a therapeutic proton pencil scanning beam (PBS) in a 300 × 300 × 600 mm3 water phantom was performed using different types of thermoluminescence detectors (MTS-7, MTS-6, MTS-N, TLD-700), radiophotoluminescent detectors (GD-352M and GD-302M) and track-etched detectors (PADAC). Neutron and gamma-ray doses were experimentally determined at 200 points within the phantom. In parallel, GEANT 4 Monte Carlo code was applied to calculate neutron and gamma radiation spectra at the position of each detector. The second part of the measurement campaign was focused on measuring and testing different commercially available active dosimetry systems (Bonner sphere systems, TEPCs (Hawk) and proportional counters) for measurements of secondary radiation generated by a PBS. Measurements of neutron ambient dose equivalents, H*(10), were performed at several positions inside and outside the treatment room whilst irradiating the water phantom. An overview of the selected final results of stray radiation in proton therapy measured with active and passive detectors will be presented.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Interdisciplinarne prirodne znanosti

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