Triple-negative breast cancer (TNBC) patients have usually poor outcome after chemotherapy and early prediction of therapeutic response would be helpful. 18F-FDG-PET/CT acquisitions are often carried out to monitor variation in metabolic activity associated to response to the therapy, despite moderate accuracy and radiation exposure limit its application. The glucoCEST technique relies on the use of unlabelled D-glucose to assess glucose uptake with conventional MRI scanners and is currently under active investigations at clinical level. This work aims at validating the potential of MRI glucoCEST in monitoring early therapeutic responses in a TNBC tumor murine model.
Methods: Breast tumor (4T1) bearing mice were treated with doxorubicin or dichloroacetate for one week. PET/CT with 18F-FDG and MRI-glucoCEST were performed at baseline and after 3 cycles of treatment. Metabolic changes measured with 18F-FDG-PET and glucoCEST were compared and evaluated with changes in tumor volumes.
Results: Doxorubicin treated mice showed a significant decrease in tumor growth when compared to the control group. GlucoCEST imaging provided early metabolic response after three cycles of treatment, conversely, no variations were detect by in 18F-FDG uptake. Dichloroacetate treated mice did not show any decrease either in tumor volume or in tumor metabolic activity as assessed by both glucoCEST and 18F-FDG-PET.
Conclusions: Early metabolic changes during doxorubicin treatment can be predicted by glucoCEST imaging that appears more sensitive than 18F-FDG-PET in reporting on early therapeutic response. These findings support the view that glucoCEST may be a sensitive technique for monitoring metabolic response, but future studies are needed to explore the accuracy of this approach in other tumor types and treatments.
18F-FDG PET/CT for the Early Evaluation of Response to Neoadjuvant Treatment in Triple-Negative Breast Cancer: Influence of the Chemotherapy Regimen
