Cellular response to proton radiation

0504674 - ÚJF 2020 CZ eng D - Dizertace
Jelínek Michaelidesová, Anna
Cellular response to proton radiation.
České vysoké učení technické, Fakulta jaderná a fyzikálně inženýrská, Katedra dozimetrie a aplikace ionizujícího záření. Obhájeno: Praha. 3. 9. 2018. - Praha: CTU, 2018. 109 s.
Grant CEP: GA ČR(CZ) GBP108/12/G108
Institucionální podpora: RVO:61389005
Klíčová slova: proton therapy * relative biological effectiveness * bystander effect * scattered beam * pencil beam
Obor OECD: Radiology, nuclear medicine and medical imaging

The aim of the dissertation was to examine several aspects of the biological effectiveness of therapeutic proton beams. From the in-vitro study at two proton facilities using 30 MeV proton beams and three biological endpoints (cell survival, percentage of binuclear cells containing micronuclei, and micronuclei frequencies) for normal human neonatal dermal fibroblasts, relative biological effctiveness values of 1.36+-0.21 for the scanning beam and 1.29 +- 0.05 for the broad beam at 50% survival level compared to a 60Co source were found. The percentage of binuclear cells containing micronuclei express a linear behavior with increasing dose for both proton beams and gamma-rays as well. The micronuclei frequencies express a linear-quadratic behavior with increasing dose for the three different beams. Examinating the bystander effect using the medium transfer method, normal human neonatal dermal fibroblasts and cell survival as the biological endpoint, no significant differences between protons and photons were found. Investigating the relative biological effectiveness at several positions of a Spread-out Bragg peak formed by a clinical pencil proton beam, normal human neonatal dermal fibroblasts, cell survival and micronuclei frequencies as biological endpoints, relative biological effectiveness values at the distal position of Spread-out Bragg peak were estimated to be 2.05 +- 0.44, 1.85 +- 0.42, 1.53 +- 0.38 for survival levels 90, 50 and 10%, respectively. An increasing complexity of chromosomal DNA damage was observed from the micronuclei assay towards the distal end of the Spread-out Bragg peak, where the linear energy transfer values are higher. Similar observations were obtained using fractionated irradiation schemes, fibroblasts AG01522 and cell survival as a biological endpoint.
Trvalý link: http://hdl.handle.net/11104/0296254