[The morbidity and mortality review meetings in radiotherapy departments: Procedure, implementation and prospects of the "Proust" French national project]. / Revue de morbidité et mortalité en radiothérapie : procédure, implémentation et perspectives du projet national français « Proust ¼.

Radiation-induced acute and late toxicity depends on several parameters. The type, severity and duration of morbidity are mainly related to irradiated volume, total dose and its fractionation and the intrinsic radiosensitivity of the patients. The follow-up of these toxicities is essential. However, unlike many specialties, morbidity and mortality reviews procedures are not developed as part of quality governance programs in radiation therapy departments for the monitoring of toxicity which sometimes hinder the patients' quality of life. One French survey published within the framework of the project entitled Prospective Registration of Morbidity and Mortality, Individual Radiosensitivity and Radiation Technique (Proust), conclude that there was a lack of knowledge of morbidity and mortality reviews and considerable confusion between these reviews and other quality processes without perspective for the local morbidity and mortality reviews development in a large number of the participated centers. In this article, we will discuss the procedure of the "ideal morbidity and mortality reviews" and its implementation through a monocentric experience started in 2015. Thus, the Proust project is a unique opportunity to implement and standardize a national morbidity and mortality reviews implementation in radiation therapy departments by involving the French regions.

[Biologic effects of high doses per fraction]. / Effets biologiques des hautes doses par fraction.

The radiobiological concepts described for conventional doses per fraction (1.8 to 2Gy) seem difficult to translate to high doses per fraction radiobiology. In fact, specific mechanisms are involved during high dose per fraction irradiation, involving vascular microenvironment damage and anti tumor immune response. The "5R's" of "classical" radiobiology (factors influencing the response of healthy or cancer cells to irradiation) seem to play a less important role in case of high doses per fraction. In addition, applicability of the linear quadratic model in this context is debated. It is therefore difficult to obtain reliable equivalent doses, hence the importance of including our patients in clinical trials, especially in case of concomitant systemic treatments. In addition to stereotactic radiotherapy, flash irradiations defined by a dose rate approximately 2000 times faster than "conventional" irradiation can also deliver high doses per fraction, with a much better tolerance for normal tissue without loss of anti tumor efficacy. Finally, availability of robust prospective data is a prerequisite to answer the question of short and long-term risk/benefit ratio of these different irradiation techniques.

[Adjuvant and neoadjuvant radiotherapy in breast cancer: A literaure review and update on the state of the evidence in 2020]. / Radiothérapie adjuvante et néoadjuvante des cancers du sein : mise au point sur les données de la littérature disponibles en 2020.

Radiation therapy has benefited from many developments over the past 20 years. These developments are mainly linked to the technology, imaging and informatics evolutions which allow better targets definitions, ensure better organs-at-risk sparing and excellent reproducibility of treatments, with a perfect control of patient positioning. In breast cancer radiotherapy, the evolution was marked by the possibility of reducing the duration of treatments from 6-7 to 3-4 weeks by using hypofractionated regimens, or by further reducing the irradiation to one week when treatment is solely focalised to the tumour bed. This concept of accelerated partial breast irradiation has challenged the paradigm of the obligation to irradiate the whole breast after conservative surgery in all patients. In addition, the technical mastery of accelerated partial breast irradiation and the development of stereotactic radiotherapy techniques are currently contributing to the development of research projects in neoadjuvant settings. Thus, numerous ongoing studies are evaluating the impact of high-dose preoperative tumour irradiation, alone or in combination with systemic treatments, on biological tumor changes, on anti-tumour immunity, and on the pathologic complete response, which is considered as predictive of better long-term survival in some molecular breast cancer subtypes. In this review, we discuss all these developments which allow breast radiation therapy to enter the era of personalisation of treatments in oncology.