Early prediction of triple negative breast cancer response to cisplatin treatment using diffusion-weighted MRI and 18 F-FDG-PET.

BACKGROUND: We evaluated the potential of diffusion-weighted MRI (DW-MRI) and 18 F-FDG-PET for the early prediction of a triple negative breast cancer (TNBC) response to cisplatin.

METHODS: Cisplatin-treated TNBC tumor-bearing mice were categorized as responders or non-responders based on the tumor growth rate. DW-MRI and 18 F-FDG-PET were performed before and after treatment (day 0 and days 3 and 7, respectively). The average apparent diffusion coefficient value (ADCmean ), the highest standardized uptake value (SUVmax ), and the metabolic tumor volume (MTV) were measured. The ratios of each parameter relative to day 0 were calculated [ΔADCmean (day 3) and (day 7), ΔSUVmax (day 3) and (day 7), and ΔMTV (day 3) and (day 7), respectively]. Overall survival rates were compared based on the thresholds determined by these parameters.

RESULTS: Both the day 3 and day 7 ratios of ADCmean and MTV showed significant differences between the responder and non-responder groups, whereas the ratios of SUVmax did not. Mice with ΔADCmean (day 3) exceeding the threshold showed a longer overall survival rate. Mice with ΔSUVmax (day 7), ΔMTV (day 3), and ΔMTV (day 7) below the respective thresholds showed a longer overall survival rate.

CONCLUSIONS: The ratios of ADCmean , SUVmax , and MTV have the potential to predict the therapeutic response and to screen non-responders in the ultra-early phase following cisplatin treatment in patients with TNBC.