Naslov
Secondary radiation dose measurements in scanning proton radiotherapy Overview of activity within EURADOS WG9 (SG2)

Autori
Knežević, Željka on behalf of EURADOS WG9

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

Izvornik
Proceedings of the 10th International Workshop on Ionizing Radiation Monitoring / Takayoshi Yamamoto - Ōarai : Chiyoda Technol Corporation (CTC), 2015, 281-288

Skup
10th International Workshop on Ionizing Radiation Monitoring

Mjesto i datum
Ōarai, Japan, 28.02.2015. - 02.03.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
proton radiotherapy; secondary doses; TLD; RPL

Sažetak
Proton therapy is used increasingly in cancer treatment because of the possibility of sparing healthy tissue close to the target volume. Proton beams show an increase in energy deposition with penetration depth up to a sharp maximum at the end of their range and almost no dose is deposited in the normal tissue beyond the Bragg peak. Thus cancer cells may be destroyed whilst surrounding normal tissue is spared more than in conventional radiotherapy with x-rays However, the interactions of protons with matter result in the production of secondary radiation comprised mostly of neutrons and gamma radiation. Unwanted doses, deposited distantly from the target volume (out-of-field doses), may lead to an increasing probability of late effects of radiotherapy including the generation of secondary cancers. The hadron therapy sub-group of EURADOS Working Group 9 (Radiation protection in medicine) is engaged in a measurement campaign designed to investigate the secondary radiation generated by a scanning proton beam. Experiments were carried out in the IBA (230 MeV) active-scanning proton beam therapy facility in Trento, Italy and in Krakow, Poland. The first part of the work included the characterization of the neutron and gamma radiation field inside the water tank phantom using different passive dosimetry systems A volume of 10 x 10 x 10 cm3 inside the water phantom (60 x 30 x 30 cm3) was irradiated uniformly to a dose of 100 Gy. Depth dose distributions along the beam axis and profiles at various depths were measured. The second part of the measurement campaign was designed to measure out-of-field organ doses using 5 and 10 year-old anthropomorphic phantoms also with different types of passive dosimeters. The following dosimeters were used: thermoluminescent (TLD-700, MTS-7, MTS-6 and MTS-N), radiophotoluminescent (GD-352M and GD302-M) optically stimulated (OSL) and CR-39 track detectors. The detailed analysis of results measured with different dosimetry systems combined with future Monte Carlo calculations will give valuable information about doses from scattered radiation distant from the target volume. . This will add to the knowledge of out-of-field doses in active scanning proton therapy and help confirm the advantages of such a technique in sparing healthy organs, compared with conventional or intensity modulated radiotherapy techniques using X-rays, despite the presence of stray neutrons.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija, Kliničke medicinske znanosti

POVEZANOST RADA