Fig. 4

Clinical data: A 38-year-old woman with left breast cancer (T3N0). Histologic findings demonstrated grade III invasive ductal carcinoma (triple negative). Post-operative pathologic findings revealed complete absence of tumor cells, wide areas of necrosis as well as free surgical margins confirmed with BCS(ypT0N0). A the first row is (a–c) Breast MR images prior to neoadjuvant chemotherapy demonstrate a 5 × 3.9 cm irregular macro-lobulated rim enhancing mass in the left breast on axial post-contrast (a) images restricted diffusion (b) with an ADC value of 0.4 (c).The second row (d–f) Breast MR images during neoadjuvant chemotherapy demonstrate significant regression in size of the previously noted left breast mass, leaving behind linear non mass enhancement, measuring 1.4 × 1.2 cm (d), with still restricted diffusion signal in DWI with ADC value about 0.4 in images (e, f). Δ diameter of lesion = 58% regression “partial response”. B The first row is 18FDG-PET/CT images prior to chemotherapy demonstrate a metabolically active 18FDG avid hyper-dense well circumscribed rounded mass in the left breast on (a) axial CT, (b) axial PET and (c) axial fused PET/CT images (SUVmax = 12.9, SUVmean = 3.8, MTV = 72.6, TLG = 376). The second row (d–f) 18FDG-PET/CT images during chemotherapy demonstrate significant metabolic and anatomic regression in the previously detected left breast mass with clips seen within the mass on (d) axial CT, (e) axial PET and (f) axial fused PET/CT images (SUVmax = 4, SUVmean = 1.6, MTV = 32.4, TLG = 52.4, ΔSUVmax = 68.9% regression) “partial response”