After qualifying as a radiation oncologist in April 2001, I first worked for 2 years as a staff member in the NKI, focussing on breast cancer, lung cancer and prostate cancer, and having a 50% clinical job and 50% research job. In 2003, I moved to Maastricht, where I started as a staff member, mainly focussing on breast cancer. Since 2009, I also became involved in management positions, resulting in my current position as a Director Patient Care of Maastro, and Head of the Radiotherapy department of the MUMC+. My research is focused on improving the quality of breast cancer radiotherapy. Apart from several projects and trials aimed to either improve locoregional control or reduce side-effects, I have a special focus on better selection of patients for whom radiotherapy is indicated. For better selection, I strongly believe that shared decision making is crucial, for which we need 1) to get more insight in medical outcomes such as recurrence rate and side-effects, 2) in patient preferences, 3) in strategies to implement shared decision making. Therefore, I have been (co) PI of several (inter)national studies to optimise the indication for locoregional treatment of breast cancer patients, based objective outcome data, and on subjective patient preferences. For SDM, I have been PI of the development, evaluation and/or implementation of 3 breast cancer decision aids: 1) for the choice of mastectomy vs breast conserving therapy (available at Zorgkeuzelab, PhD thesis Wilma Savelberg, June 2019); 2) for the choice of after-care strategy (available at www.beslissamen.nl, thesis Linda Klaassen expected 2nd half 2021); and 3) for the choice (additional) radiotherapy yes or no (Dutch and English version available at www.beslissamen.nl, Thesis Daniela Raphael, June 2021). My studies aimed at improving local control of reducing side-effects encompass e.g. The Young Boost Trial (YBT), the IRMA trial, the RAPCHEM study. The YBT is a randomized clinical trial in breast cancer patients ≤ 50 years, investigating the effect of an additional boost of 10 Gy on local control and cosmetic outcome. The IRMA trial is aimed at minimizing toxicity, by comparing partial breast irradiation with whole breast irradiation. The RAPCHEM study is a prospective cohort study aimed to evaluate de-escalated radiotherapy guidelines in breast cancer patients treated with primary systemic treatment. In addition, as member and chair of the BOOG working group locoregional treatment of breast cancer, I have been member of the writing committee of four grants (3 KWF and 1 Pink Ribbon grant) for two national randomized clinical trials, aimed to minimize axillary treatment in patients with early breast cancer and 1 prospective cohort study, to evaluate axillary treatment after primary systemic treatment (MiniMax study, PI: M.L. Smidt), which actually is a follow-up study of the RAPCHEM. Another approach to reduce side-effects is deals with improved individualization of RT techniques, i.e. by improving regular photon therapy nationwide (2 national SKMS projects), but also by development, implementation and evaluation of proton therapy in breast cancer. In addition, the combination of pre-operative radiotherapy with oncoplastic surgery is part of this research line (KWF grant for a randomized national trial will be re-submitted). Another more recent research line deals with implementation of innovations in radiotherapy (Thesis Prof.dr. M.L. Jacobs, June 2018), where I focus specifically on implementation of shared decision making and protontherapy. I have an H-index of 45 (Web of Science) (April 2021).