18F-DG PET/CT in detection of recurrence and metastasis of colorectal cancer

Figure 1 PET/CT imaging showing local recurrent rectal carcinoma in a 49-year-old female postoperative rectal cancer patient. CT scan did not find definite recurrence signs. PET imaging detected hyper-intensive radioactivity by the left side of uterus. The SUV_max was 7.5 and the T/N was 9.4. Combined PET/CT imaging indicated elevated ¹⁸F-DG uptake of the anastomosis. The reoperation confirmed a recurrent tubular adenocarcinoma of the rectum.

Figure 2 PET/CT imaging showing isolated hepatic metastasis in a 69-year-old female postoperative sigmoid carcinoma patient. CT scan did not find definite recurrence signs. PET imaging detected localized hepatic subcapsular hyper-intensive radioactivity. Local resection of liver lobe was performed in the reoperation, and metastatic adenocarcinoma was confirmed.

Figure 3 PET/CT imaging showing hepatic metastasis after local therapy in a 60-year-old male postoperative colon cancer patient. ¹²⁵I seeds brachytherapy was performed in the metastatic lesion of the liver, causing necrosis and ¹⁸F-DG uptake decrease of the lesion. However, additional localized hepatic subcapsular hyper-intensive radioactivity was detected, indicating that new liver metastasis had occurred.