Image-guided treatment of breast cancer: a patient-centered approach to minimally invasive therapy

Abstract

This thesis describes a first step of minimally invasive treatment application in breast cancer patients and focuses on patient selection for these therapies. First, studies regarding of the use of minimally invasive treatments in a research setting are described. The results of magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) ablation with a dedicated breast system are presented first. Because more clinical studies will be required to assess its efficacy, reliable outcome assessment in the research setting remains important. The histopathological appearance of ablated tissue with MR-HIFU and radiofrequency ablation (RFA) was evaluated as a guideline for pathologists involved in minimally invasive treatment studies. The clinical introduction of a new treatment relies on efficacy, but also on cost-effectiveness. The costs of MR-HIFU ablation were compared with costs of conventional breast-conserving treatment (BCT) using data from the clinical MR-HIFU study combined with model- and expert-based estimations. Several aspects of patient selection for minimally invasive treatments are described in the second part. In previous research, treatment results of minimally invasive therapies, including MR-HIFU ablation and RFA, were promising, but far from perfect. Based on these studies it can be concluded that technical issues still need to be solved and even more importantly, patient selection should improve. Therefore, this thesis aimed at pre-treatment assessment of several factors possibly influencing treatment results. After minimally invasive treatment, no surgical excision specimens are available, which means that prognostic factors need to be assessed prior to therapy. The concordance of tumour grade on biopsy and excision specimens was evaluated in a meta-analysis. Furthermore, a prediction model for the assessment of ductal carcinoma in situ around the primary tumour using magnetic resonance imaging (MRI) was developed. Additionally, the value of pre-treatment breast MRI in breast cancer was evaluated, emphasising the increasingly important role of MRI in breast cancer care. The increasing number of treatment possibilities and patient desire for shared decision making indicate that patient selection should not only be based on characteristics of their cancers, but also on patient preferences. Therefore, this thesis contains a chapter in which the preference of patients for different treatment options is assessed.