Maximum standardized uptake value (SUVmax)

¹⁸F-fluoro-2-deoxy-glucose (¹⁸F-FDG)-PET was performed with a dedicated PET camera (SIEMENS Biograph Sensation 16; SIEMENS, Erlangen Germany) before surgery. All patients fasted for 6 h before scanning. The dose of ¹⁸F-FDG administered was 3.7 MBq/kg of the patient’s body weight. After a 60-min uptake period, an emission scan was acquired for 3 min per bed position, and a whole-body scan was performed according to the height of each patient. After image reconstruction, a two-dimensional (2D) round region of interest (ROI) was drawn on a slice after visual detection of the highest count on the fused CT image. For lesions with negative or faintly positive PET findings, the ROI was drawn on the fusion image obtained with the corresponding CT image. From those ROIs, the SUV_max was calculated by two radiologists.