F. Liewald et al., How useful is positron emission tomography for lymphnode staging in non-small-cell lung cancer?, THOR CARD S, 48(2), 2000, pp. 93-96
The introduction of positron emission tomography (PET) raises the question
of the new method's capabilities in the staging of mediastinal lymphnodes,
since PET differentiates between metabolically active and inactive tissues.
80 patients with histologically confirmed non-small-cell lung cancer (NSCL
C) underwent PET scanning with 18-F-marked fluorodeoxyglucose (FDG). Extens
ive dissection of mediastinal lymphnodes (18-28 lymphnodes recovered) was p
erformed in 78 cases. Metastasis to mediastinal lymphnodes were observed in
25 patients (N2: 22; N3: 3). Results: Primary Tumor: FDG-PET showed signif
icant enhancement of the primary tumor in 78 of 80 patients (sensitivity: 9
7%). Lymphnode involvement: FDG-PET was positive in 23 of 25 patients with
surgically confirmed lymphnode involvement (sensitivity: 92%). After a medi
an follow up intervall of 18 months. 11 patients with false positive lymphn
ode uptake were still alive: 10 of them showed no tumor recurrency. On the
basis of these findings, enlarged mediastinal lymphnodes visualized at CT,
but negative at FDG-PET are free of metastatic involvement with a sensitivi
ty of 92%. FDG uptake of mediastinal lymphnodes at PET, however, should not
be interpreted as proof of malignancy.