Fig. 1
An 81-year-old woman underwent FDG PET/CT for staging work-up of colon cancer in the proximal transverse colon. In maximal intensity projection (a) and transaxial PET/CT (b) images, the tumor lesion (arrows) showed intensely increased FDG uptake with a maximum standardized uptake value (SUV) of 17.79. Using Nestle’s adaptive threshold method, the tumor lesion (purple color) was automatically delineated on PET images (c), and the SUV intensity histogram of the tumor lesion was made (d). Metabolic tumor volume, total lesion glycolysis, coefficient of variation, entropy, and uniformity extracted from the tumor lesion were 97.52 cm3, 1000.17 g, 0.233, 4.66, and 0.047, respectively. Increased FDG uptake of the bone marrow (BM) and spleen was observed in transaxial (e) and sagittal (f) PET/CT images, revealing BM SUV of 2.09, spleen SUV of 2.06, BLR of 1.00, and SLR of 0.98. The patient underwent curative surgery, and immunohistochemical analysis of the surgical specimen demonstrated grade 0 of CD4 + cell infiltration (g), grade 0 of CD8 + cell infiltration (h), grade 2 of CD163 + cell infiltration (i), grade 2 of interleukin-6 expression (j), and grade 1 of matrix metalloproteinase-11 expression (k) in tumor tissue. The patient experienced cancer recurrence 7 months after the surgery