Variations in (18)F-FDG uptake in breast cancer depending on PET/CT acquisition position

AIM: To evaluate the variability of quantitative 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) combined with computed tomography (CT) parameters depending on acquisition position in a dual-position protocol for breast cancers. MATERIALS AND METHODS: For initial staging work-up, whole-body PET/CT was first acquired in a supine position, and then followed by a regional breast scan in a prone position. The maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were measured on both acquisition positions. MTV50 and TLG50 were calculated with a threshold set to be 50% of SUVmax, and MTV2.5 and TLG2.5 with a fixed SUV threshold of 2.5. RESULTS: The median SUVmax of breast cancers measured on the supine scans was 4.88, and 4.49 on the prone images (p