GlucoCEST MRI for the early evaluation response to chemotherapeutic and metabolic treatments in a murine triple negative breast cancer: a comparison with 18F-FDG-PET.

PurposeTriple-negative breast cancer (TNBC) patients have usually poor outcome after chemotherapy and early prediction of therapeutic response would be helpful. [18F]F-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. ProceduresBreast tumor (4T1) bearing mice were treated with doxorubicin or dichloroacetate for one week. PET/CT with [18F]F-FDG and MRI-glucoCEST were performed at baseline and after 3 cycles of treatment. Metabolic changes measured with [18F]F-FDG-PET and glucoCEST were compared and evaluated with changes in tumor volumes. ResultsDoxorubicin 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]F-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]F-FDG-PET. ConclusionsEarly metabolic changes during doxorubicin treatment can be predicted by glucoCEST imaging that appears more sensitive than [18F]F-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.