68Ga-FAPI Versus 18F-FDG PET/CT in Recurrent Undifferentiated Pleomorphic Sarcoma of Colon Mesentery

Abstract A 56-year-old woman presented with primary undifferentiated pleomorphic sarcoma of colon mesentery underwent complete surgical resection approximately 7 months ago. Abdominal contrast-enhanced CT showed a new mass in the descending colon, suggesting a high probability of tumor recurrence. Under a clinical trial, the patient underwent 68 Ga-FAPI and 18 F-FDG PET/CT to detect whether there are additional recurrent lesions. Compared with 18 F-FDG PET/CT, the recurrent undifferentiated pleomorphic sarcoma of colon mesentery, peritoneum, pelvic lymph node, and lung metastases showed higher uptake in 68 Ga-FAPI PET/CT. This case showed that 68 Ga-FAPI might be a promising radiopharmaceutical in the evaluation of undifferentiated pleomorphic sarcoma.