Comparison of fast-neutron contamination of different models of Siemens medical linacs with CR-39 film.
CR39 film
Chemical etching
Siemens
linac
neutron contamination
Journal
Journal of cancer research and therapeutics
ISSN: 1998-4138
Titre abrégé: J Cancer Res Ther
Pays: India
ID NLM: 101249598
Informations de publication
Date de publication:
Historique:
entrez:
16
9
2021
pubmed:
17
9
2021
medline:
27
1
2022
Statut:
ppublish
Résumé
Nowadays, radiotherapy has an important role in the treatment of cancer. The use of medical linacs in radiotherapy can have risks for patients. When radiotherapy is performed with photons with energies higher than 8 MeV, due to the photonuclear reaction of photons with various components in the head of the accelerator, the neutron is produced. This imposes an unwanted neutron dose to the patient. The purpose of this study is evaluation and comparison of fast-neutron contamination with increasing of field size and depth for Siemens Primus (15 MV), Siemens Primus Plus (18 MV), and Siemens Artiste (15 MV) linacs. Neutron dosimetry was carried out with CR-39 films, as a fast-neutron dosimeter, using chemical etching technique. Measurements were performed in depths of 0.5, 2, 3, and 4 cm and source-to-surface distance of 100 cm. Field sizes were 10 cm × 10 cm and 30 cm × 30 cm. The results of measurements showed that, with increasing depth, equivalent dose is reduced. In addition, fast-neutron equivalent dose decreases with increasing the field size. Siemens Primus Plus had the highest neutron contamination in comparison with the two other linacs. Deeper tissues receive less fast-neutron doses. In radiation therapy with high-energy photon beams, neutron dose delivered to the patients should be taking into account.
Sections du résumé
BACKGROUND
BACKGROUND
Nowadays, radiotherapy has an important role in the treatment of cancer. The use of medical linacs in radiotherapy can have risks for patients. When radiotherapy is performed with photons with energies higher than 8 MeV, due to the photonuclear reaction of photons with various components in the head of the accelerator, the neutron is produced. This imposes an unwanted neutron dose to the patient. The purpose of this study is evaluation and comparison of fast-neutron contamination with increasing of field size and depth for Siemens Primus (15 MV), Siemens Primus Plus (18 MV), and Siemens Artiste (15 MV) linacs.
MATERIALS AND METHODS
METHODS
Neutron dosimetry was carried out with CR-39 films, as a fast-neutron dosimeter, using chemical etching technique. Measurements were performed in depths of 0.5, 2, 3, and 4 cm and source-to-surface distance of 100 cm. Field sizes were 10 cm × 10 cm and 30 cm × 30 cm.
RESULTS
RESULTS
The results of measurements showed that, with increasing depth, equivalent dose is reduced. In addition, fast-neutron equivalent dose decreases with increasing the field size.
CONCLUSION
CONCLUSIONS
Siemens Primus Plus had the highest neutron contamination in comparison with the two other linacs. Deeper tissues receive less fast-neutron doses. In radiation therapy with high-energy photon beams, neutron dose delivered to the patients should be taking into account.
Identifiants
pubmed: 34528531
pii: JCanResTher_2021_17_4_853_263532
doi: 10.4103/jcrt.JCRT_342_18
doi:
Substances chimiques
CR 39
25656-90-0
Polyethylene Glycols
3WJQ0SDW1A
Types de publication
Comparative Study
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
853-856Déclaration de conflit d'intérêts
None