[en] Aim: Determine the discrepancies between measured and estimated dose indexes. Provide a better estimation of the patient dose and monitor the CT performances during examinations.

[en] Individual response to ionizing radiation is an important information required to apply an efficient radiotherapy treatment against tumour and to avoid any adverse effects in normal tissues. In 1981, Fertil and Malaise have demonstrated that the post-irradiation local tumor control determined in vivo is correlated with clonogenic cell survival assessed in vitro. Furthermore, these authors have reminded the relevance of the concept of intrinsic radiosensitivity that is specific to each individual organ (Fertil and Malaise, 1981) [1]. To date, since clonogenicity assays are too time-consuming and do not provide any other molecular information, a plethora of research groups have attempted to determine the molecular bases of intrinsic radiosensitivity in order to propose reliable and faster predictive assays. To this aim, several approaches have been developed. Notably, the recent revolution in genomic and proteomics technologies is providing a considerable number of data but their link with radiosensitivity still remains to be elucidated. On another hand, the systematic screening of some candidate genes potentially involved in the radiation response is highlighting the complexity of the molecular and cellular mechanisms of DNA damage sensing and signalling and shows that an abnormal radiation response is not necessarily due to the impairment of one single protein. Finally, more modest approaches consisting in focusing some specific functions of DNA repair seem to provide more reliable clues to predict over-acute reactions caused by radiotherapy. In this review, we endeavored to analyse the contributions of these major approaches to predict human radiosensitivity. (authors)

[en] At the beginning of the 21. century, radiation biology is at a major turning point in its history. It must meet the expectations of the radiation oncologists, radiologists and the general public, but its purpose remains the same: to understand the molecular, cellular and tissue levels of lethal and carcinogenic effects of ionizing radiation in order to better protect healthy tissues and to develop treatments more effective against tumours. Four major aspects of radiobiology that marked this decade will be discussed: technological developments, the importance of signalling and repair of radiation-induced deoxyribonucleic acid (DNA) damage, the impact of individual factor in the response to radiation and the contribution of radiobiology to better choose innovative therapies such as proton-therapy or stereotactic body radiation therapy (SBRT). A translational radiobiology should emerge with the help of radiotherapists and radiation physicists and by facilitating access to the new radio and/or chemotherapy modalities. (authors)

[en] Purpose: To assess in vitro mammographic radiation-induced DNA damage in mammary epithelial cells from 30 patients with low (LR) or high (HR) family risk of breast cancer. Materials and methods: Spontaneous and radiation-induced DNA double-strand breaks (DSB) were quantified by using immunofluorescence of the phosphorylated H2AX histone (γH2AX) in different conditions of mammography irradiation (2, 4, 2 + 2 mGy). Results: HR patients showed significantly more spontaneous γH2AX foci than LR patients (p = 0.014). A significant dose-effect was observed, with an exacerbation in HR patients (p = 0.01). The dose repetition (2 + 2 mGy) provided more induced and more unrepaired DSB than 2 mGy and 4 mGy, and was exacerbated in HR (p = 0.006). Conclusions: This study highlights the existence of DSB induced by mammography and revealed by γH2AX assay with two major radiobiological effects occurring: A low-dose effect, and a LOw and Repeated Dose (LORD) effect. All these effects were exacerbated in HR patients. These findings may lead us to re-evaluate the number of views performed in screening using a single view (oblique) in women whose mammographic benefit has not properly been proved such as HR patients. (authors)