Fig. 2

Clinical data: A 48-year-old woman with left breast cancer (T3N1). Histologic findings demonstrated grade II invasive ductal carcinoma (luminal B1). Post-operative pathology revealed IDC grade I with low grade DCIS with partial effect to therapy confirmed with BCS(ypT1N1). A The first row (a–c) Breast MR images prior to neoadjuvant chemotherapy demonstrate a 3 × 2.8 cm irregular microlobulated enhancing mass in the left breast on axial post-contrast (a) images restricted diffusion (b) with an ADC value of 0.9 (c). The second (d–f) Breast MR images during neoadjuvant chemotherapy demonstrate partial regression in size of the previously noted left breast mass with inserted clips seen within, measuring 2.4 × 2.2 cm (d), with still restricted diffusion signal in DWI with ADC value about 1.2 in images (e) (f). Δ dimeter of lesion = 20% regression. “Stable disease”. B The first row is 18FDG-PET/CT images prior to neoadjuvant chemotherapy demonstrate a metabolically active 18FDG avid hyper-dense irregular speculated mass in the left breast on (a) axial CT, (b) axial PET and (c) axial fused PET/CT images (SUVmax = 9.9, SUVmean = 5.7, MTV = 28.8, TLG = 164.1). The second row (d–f) 18FDG-PET/CT images during chemotherapy metabolic progression of such lesion, however anatomic regression noted on (d) axial CT, (e) axial PET and (f) axial fused PET/CT images (SUVmax = 11.5, SUVmean = 6.7, MTV = 5.2, TLG = 34.8, ΔSUVmax = 13.9% progression) “progressive disease”