title: Can high dose rates used in cancer radiotherapy change therapeutic effectiveness?
abstract: Current cancer radiotherapy relies on increasingly high dose rates of ionising radiation (100-2400 cGy/min). It is possible that changing dose rates is not paralleled by treatment effectiveness. Irradiating cancer cells is assumed to induce molecular alterations that ultimately lead to apoptotic death. Studies comparing the efficacy of radiation-induced DNA damage and apoptotic death in relation to varying dose rates do not provide unequivocal data. Whereas some have demonstrated higher dose rates (single dose) to effectively kill cancer cells, others claim the opposite. Recent gene expression studies in cells subject to variable dose rates stress alterations in molecular signalling, especially in the expression of genes linked to cell survival, immune response, and tumour progression. Novel irradiation techniques of modern cancer treatment do not rely anymore on maintaining absolute constancy of dose rates during radiation emission: instead, timing and exposure areas are regulated temporally and spatially by modulating the dose rate and beam shape. Such conditions may be reflected in tumour cells' response to irradiation, and this is supported by the references provided.
authors.affiliation: Centre for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology Gliwice Branch, Gliwice, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Konopacka
authors.affiliation: Centre for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology Gliwice Branch, Gliwice, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Rogoliński
authors.affiliation: Centre for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology Gliwice Branch, Gliwice, Poland.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Sochanik
authors.affiliation: Department of Radiotherapy and Brachytherapy Planning, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology Gliwice Branch, Gliwice, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Ślosarek
keywords: apoptosis; cancer radiotherapy; dose rate; gene expression profile; genetic damage; ionising radiation