Extended staging of oesophageal cancer using FDG-PET - a critical appraisal

Oesophageal cancer (OC) is a highly aggressive tumour with unfavorable prognosis due to early stages metastases. Treatment and survival rates are highly correlated with tumour wall invasion, lymphatic involvement and metastatic spread. Thus, an accurate staging at initial diagnosis is fundamental for optimal management. In the present review article the potential role of the FDG-PET in the staging of OC is discussed.

A systematic review of all papers published in PubMed until June 2010 was performed.

Endoscopic ultrasound (EUS) is helpful for T and N staging but not for M staging. CT plays a complementary role to EUS in T staging, especially in excluding T4 disease. However, in N staging, CT relies on "size criteria" (<1cm=benign, >1cm=malignant) which reduces its sensitivity and specificity. FDG-PET has been demonstrated to be a very helpful tool in staging and re-staging OC. Most OCs demonstrate high FDG accumulation and are usually well detected with PET. Unfortunately, PET cannot reveal very small lesions due to its limited spatial resolution, therefore limiting the usefulness of PET in T staging. In N staging, an FDG positive node is highly likely to contain disease. However, FDG-PET cannot reliably separate the primary site from closely adjacent nodes. The real and unquestionable additional diagnostic value of FDG-PET in comparison to CT and EUS is in evaluating distant metastases.

It appears reasonable to include FDG PET/CT in the diagnostic algorithm of patients with OC in order to better define the optimal therapeutic approach.