Zusammenfassung
Urachal cancer is a very rare malignancy. There is no consensus on the optimal form of staging for this disease. In this study, we evaluated FDG-PET/CT for staging urachal cancer in 40 patients. We found that most of the urachal tumors can be visualized on FDG-PET/CT but that it seems to add little additional staging information compared with standard CT. Background: Urachal carcinoma (UrC) is a ...
Zusammenfassung
Urachal cancer is a very rare malignancy. There is no consensus on the optimal form of staging for this disease. In this study, we evaluated FDG-PET/CT for staging urachal cancer in 40 patients. We found that most of the urachal tumors can be visualized on FDG-PET/CT but that it seems to add little additional staging information compared with standard CT. Background: Urachal carcinoma (UrC) is a rare malignancy that often presents at an advanced stage with metastases in up to a quarter of patients. There is no consensus on the optimal form of staging for patients with UrC. In the present study, we evaluated the diagnostic value of 18 F-fluorodeoxyglucose-positron emitted tomography/computed tomography (FDG-PET/CT) for UrC. Patients and Methods: We evaluated 40 consecutive patients who were staged for urachal cancer between 2010 and 2020. They underwent a total of 62 FDG-PET/CTs (40 for primary staging, and 22 during follow-up), which were compared with standard-of-care contrast-enhanced CT (CECT). The metabolic detection of primary tumors, lymph node metastases (LNMs), peritoneal metastases (PMs), distant metastases (DMs), and local recurrence by FDG-PET/CT was evaluated. Sensitivit y and specificit y were calculated compared with CECT. Histopathology or follow-up imaging was the reference standard. Results: Of all 40 patients, 33 patients (83%) had urachal adenocarcinoma-26 (65%) with a mucinous component and 7 (17%) with invasive urothelial carcinoma. All local UrC tumors could be visualized on CT, and 80% showed increased FDG uptake. At initial staging, FDG-PET/CT detected FDG-avid LNMs, PMs, and DMs in 50%, 17%, and 25% of patients, respectively. These metastases were also visualized on CECT. During follow up, FDG-PET/CT revealed FDG-avid local recurrences that were not seen on CT in two out of eight patients (25%). Conclusion: The present study demonstrates that most UrC can be visualized on FDG-PET/CT. At initial diagnosis, FDG-PET/CT does not seem to yield additional information compared with CECT; however, FDG-PET/CT may be helpful during follow-up. This is a small study, and the findings should be corroborated with larger series. (C) 2021 Elsevier Inc. All rights reserved.
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