Staging Pathways in Recurrent Colorectal Carcinoma: Is Contrast-Enhanced 18F-FDG PET/CT the Diagnostic Tool of Choice?
Jan D. Soyka 1*,
Patrick Veit-Haibach 1,
Klaus Strobel 1,
Stefan Breitenstein 2,
Alois Tschopp 3,
Katja A. Mende 1,
Marisol Perez Lago 1,
and
Thomas F. Hany 1
1 Department of Nuclear Medicine, University Hospital Zuerich, Zurich, Switzerland
2 Department of Visceral and Transplantation Surgery, University Hospital Zuerich, Zurich, Switzerland
3 Department of Biostatistics, University of Zuerich, Zurich, Switzerland
* To whom correspondence should be addressed. E-mail: jan.soyka{at}usz.ch.
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Abstract |
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18F-FDG PET/CT has gained wide acceptance for evaluation of recurrent colorectal carcinoma. However in clinical practice, contrast-enhanced CT (ceCT) is still the first-line restaging tool. The aim of this study was to investigate the value of contrast-enhanced PET/CT (cePET/CT) as a first-line restaging tool with a special focus on the importance of the use of intravenous contrast. Methods: Fifty-four patients (17 women, 37 men; mean age, 60.3 y), referred for restaging of colorectal carcinoma, were examined with cePET/CT. Retrospective analysis was performed by 2 experienced readers by consensus: first, ceCT alone; second, non-cePET/CT; and third, cePET/CT. The number, localization, and diagnostic certainty of lesions were evaluated. Additionally, the therapeutic impact of the findings was determined. In 29 patients, histology, clinical imaging, and clinical follow-up served as the reference standard. In 25 patients, clinical follow-up and imaging served as the reference standard. Results: Overall, non-cePET/CT delivered correct additional information to the ceCT findings in 27 of 54 patients (50%). This occurred in (a) 20 of 30 patients, where ceCT was found to be inconclusive, and in (b) 7 of 24 patients with conclusive ceCT findings, where non-cePET/CT found additional lesions, leading to a therapy modification in 5 patients. Compared with non-cePET/CT, cePET/CT revealed additional information in 39 of 54 patients (72%), with therapeutic relevance in 23 patients. This large number was primarily due to correct segmental localization of liver metastases, which is crucial for surgical therapy planning. Conclusion: On the basis of its higher accuracy and therapeutic impact compared with ceCT, our data suggest that cePET/CT might be considered as the first-line diagnostic tool for restaging in patients with colorectal cancer.
Key Words:
colorectal carcinoma, recurrence, 18F-FDG, PET/CT, staging, contrast
