Images were acquired on combined PET/CT in-line systems, either Biograph Duo or Biograph Truepoint (Siemens Medical Solutions, Knoxville, TN, USA). All the patients fasted for at least 6 hr before the PET/CT examination (blood glucose concentration <130 mg/dL). After 60 min of post-injection of 370 to 550 MBq of 18F-FDG with a saline infusion, PET/CT scan were performed. In supine position, CT scan started at the orbitomeatal line and progressed to the proximal thigh (130 kVp, 80 mA, 5-mm slice thickness; 120 kVp, 50 mA, 5-mm slice thickness) and a PET scan followed immediately over the same body region. The acquired images were reconstructed using a standard ordered-subset expectation maximization (OSEM) algorithm. One radiologist with three years of experience in breast MRI reviewed the medical records and PET/CT report. In the PET/CT report, the maximum value of the standard uptake value (SUVmax) of the breast cancer was measured, and metabolic tumor responses were also evaluated after NAC using PET Response Criteria in Solid Tumor (PERCIST 1.0) (Table 2) (7 (link)). Patients with a complete metabolic or partial metabolic response (CMR or PMR) were assigned as responders, and patients with stable metabolic or progressive metabolic disease were assigned as non-responders on PET/CT.