Combined FDG-PET/CT for the detection of unknown primary tumors: systematic review and meta-analysis

Abstract

The aim of this study was to systematically review and meta-analyze published data on the diagnostic performance of combined 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the detection of primary tumors in patients with cancer of unknown primary (CUP). A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Methodological quality of the included studies was assessed. Reported detection rates, sensitivities and specificities were meta-analyzed. Subgroup analyses were performed if results of individual studies were heterogeneous. The 11 included studies, comprising a total sample size of 433 patients with CUP, had moderate methodological quality. Overall primary tumor detection rate, pooled sensitivity and specificity of FDG-PET/CT were 37%, 84% (95% CI 78–88%) and 84% (95% CI 78–89%), respectively. Sensitivity was heterogeneous across studies (P = 0.0001), whereas specificity was homogeneous across studies (P = 0.2114). Completeness of diagnostic workup before FDG-PET/CT, location of metastases of unknown primary, administration of CT contrast agents, type of FDG-PET/CT images evaluated and way of FDG-PET/CT review did not significantly influence diagnostic performance. In conclusion, FDG-PET/CT can be a useful method for unknown primary tumor detection. Future studies are required to prove the assumed advantage of FDG-PET/CT over FDG-PET alone and to further explore causes of heterogeneity.

CEA, AFP, CA125, CA153 and CA199 in Malignant Pleural Effusions Predict the Cause

“…CT scan and MRI are useful, especially in the detection of primary breast tumors. A recent meta-analysis :http://dx.doi.org/10.7314/APJCP.2014.15.1.363 CEA, AFP, CA125, CA153 and CA199 in Malignant Pleural Effusions Predict the Cause (Kwee et al, 2009) showed that, overall, FDG-PET/CT was able to detect 37% of primary tumors in patients with CUP, with both sensitivity and specificity of 84%. On the other hand, it should be realized that FDG-PET/CT is an expensive examination, and false-positive FDG-PET/CT findings may result in unnecessary additional invasive diagnostic procedures, which have associated morbidities and costs (Kwee et al, 2008).…”

The Role of 18 FDG PET-CT in Evaluation of Unknown Primary Tumours

“…Literature on the exact causes of false positive FDG-PET/CT/CT results is scarce, although benign inflammatory lesions and pulmonary infarction have been reported aetiologies [9]. The oropharynx and the lung are the two most common locations of false-positive FDG-PET/CT/CT results [10].…”

18F-FDG PET/CT as a Diagnostic Tool in Patients with Extracervical Carcinoma of Unknown Primary Site: A Literature Review

“…and A.K.H.M.) independently assessed the quality of the included studies using the quality assessment of diagnostic accuracy studies criteria modified by Kwee and Kwee [10]. Twelve methodological quality items were assessed for each study using the scores "yes," "no," or "unclear" for each item.…”