The role of FDG PET in the diagnosis of occult primary with cervical lymph node metastases : a meta-analysis study

Abstract EN

Background: Detection of the primary tumor has a key role in the management of patients with unknown primary tumors (UPT).

Purpose: The aim of this study is to assess the efficacy of 18F-FDG PET in locating occult primary lesions in patients with metastatic cervical lymphadenopathy.

Methods: A systematic search was performed by the PubMed/MEDLINE to identify and select the relevant studies published within the last 20 years (up to 25/08/2011).

Reported detection rates, sensitivities and specificities were metaanalyzed.

Subgroup analyses were performed if results of individual studies were heterogeneous.

Results: Thirty studies met the inclusion criteria.

The overall sensitivity, specificity and accuracy rates of FDG-PET in detecting unknown primary tumors were 80.6%, 82.1% and 81.5% respectively.

Furthermore, FDG-PET detected 33.5% of tumors that were not apparent after conventional workup.

Whereas PET/CT scans’ overall sensitivity, specificity and accuracy were 82.5%, 80.2% and 81.4% respectively.

Furthermore, PET/CT detected 30.7% of tumors that were not apparent after conventional workup.

There were no significant differences between the diagnostic accuracies of FDGPET and PET/CT scans.

Conclusions: 18F-FDG PET could be useful in patients with UPT for the detection of the primary tumor.

18F-FDG PET has high sensitivity, indicating the existence of few false-negative results, an important feature in the management of oncologic patients that could suggest its utility in the initial stages of the management process.