[Positron emission tomography for preoperative lymph node diagnosis in esophageal carcinoma]

Exact preoperative staging is a prerequisite for the indication and the choice of appropriate operative technique for patients with esophageal carcinoma. The objective of this prospective study was to assess whether positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) increases the accuracy of preoperative lymph node staging with standard computed tomography (CT) and thus leads to a different surgical approach.

Fifty-eight patients with carcinoma of the esophagus (46 men and 12 women) with a median age of 61 years underwent FDG-PET imaging of the neck, chest, and abdomen as well as CT of the chest and abdomen. Sensitivity, specificity, and accuracy were calculated for both imaging techniques to evaluate the detection of histologically verified lymph node metastases.

The FDG-PET showed higher specificity, whereas CT proved to be more accurate for detecting lymph node metastases not only of the abdomen (73% vs 59%) but also of the thorax (73% vs 63%). Resections were transhiatal in 23 patients and transthoracal in 16. As a supplement to conventional CT diagnostic procedure, FDG-PET was not decisive for the surgical approach.

Altogether, pretherapeutical PET imaging did not increase the accuracy of lymph node staging for our patients with esophageal carcinoma, which had already been defined through CT. Therefore, no new consequences resulted for the surgical procedure. Due to the high costs involved with PET investigation, lymph node staging with it is momentarily indicated mainly for clinical studies and when CT does not offer unequivocal results. Increased sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals and optimized apparatus resolution could lead to new indications for this staging procedure.