Multimodality imaging of breast cancer for selection and monitoring of treatment

Despite major improvements in breast cancer care, breast cancer is still a substantial cause of cancer death in Western women. Moreover, research from the past decades demonstrated that breast cancer is a heterogeneous disease. This heterogeneity warrants a personalized treatment approach. With this approach both under- and overtreatment may be minimized. Accurate imaging is essential when applying personalized treatment. The overall aim of this thesis is to investigate if, and how, the application of magnetic resonance imaging (MRI) and positron emission tomography in combination with computed tomography (PET/CT) contributes to improved personalized treatment strategies. Our first research was done in women who are eligible for breast conserving therapy (limited surgery to excise the tumor, combined with radiotherapy). We investigated the ability of MRI to accurately depict the disease extent. Moreover we presented guidelines to select women in whom a preoperative breast MRI can be avoided. Secondly, we investigated the use of PET/CT only, and in combination with MRI to monitor the treatment response in women who were treated with primary chemotherapy. The heterogeneity of breast cancer was taken into account. Our findings cover many issues that may be of importance in comparable studies. Therefore we consider our work part of on-going breast cancer research.