Abstract 102P
Background
Standard imaging techniques (SIT) as computed tomography (CT) and positron emission tomography (PET-CT), do not always yield accurate results in metastatic breast cancer (MBC), especially with bone-predominant metastases. Our study aimed to assess whether multiparametric whole-body magnetic resonance imaging (WB-MRI) shows higher accuracy for detecting bone metastases, when used in addition to CT and/or PET-CT, thereby potentially changing the therapy goal.
Methods
In this prospective study, WB-MRI was used as a baseline staging tool alongside routine SIT for two specific groups of BC patients. The first group included patients with bone-predominant lesions, candidates for CDK 4/6 inhibitors, while the second one was represented by BC patients with inconsistent imaging findings. The study sought to analyze the discrepancies between WB-MRI and SIT. Secondly, it aimed to assess the impact of WB-MRI on treatment planning as well as identify the histological subtypes which benefit most.
Results
Fifty-nine consecutive BC patients, underwent a CT and/or PET-CT followed by WB-MRI. Of these, 25 (42.4%) patients with suspicious lesions on SIT were reclassified as metastatic upon WB-MRI. In 21 patients (40%), WB-MRI led to a moification of the therapeutic approach. Specifically, the therapeutic decision changed in 11 patients (22%), due to the identification of new lesions or progression of known metastatic sites on WB-MRI alone. Remarkably, 83% of patients with lobular tumors had additional metastases discovered, and 45% of them changed treatment strategy. Additionally, in 13 patients (38%) a biopsy was spared, due to evidence of progression on WB-MRI. Among the 35 patients who underwent at least one reassessment by WB-MRI and SIT, the concordance rate was 47%. Of these, 7 patients showed non-concordant findings, resulting in a 21% modification rate of therapeutic approach.
Conclusions
This study highlighted the potential utility of WB-MRI in staging and follow-up of BC patients, especially in presence of lobular histology, as well as in patients with predominant bone lesions to overcome limits of SIT. Further prospective research is warranted to establish the role of WB-MRI as a clinical tool with consistent clinical impact.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.