Background and objective: Exact preoperative staging is a prerequisite for the indication as well as the choice of the appropriate operative technique for patients with esophageal carcinoma. In this prospective study we assessed whether positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) increases the accuracy of staging compared to standard computer tomography (CT) and leads to a different therapeutic approach.
Patients and methods: 30 patients (25 men, 5 women, median age 63 years) with histologically identified carcinoma of the esophagus (n =29) and the cardia (n = 1), respectively, were studied. All patients 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 FDG-PET and CT to evaluate the detection of histologically identified lymph node metastases and distant metastatic disease.
Results: FDG-PET showed higher specificity whereas the accuracy of the CT proved to be higher not only for the detection of abdominal lymph node metastases (67 % vs. 46 %), but also for lymph node metastases of the thorax (71 % vs. 50 %). Furthermore, the accuracy of the CT for the detection of blood-bone and lymphatic distant metastases was also higher than that of FDG-PET (72 % vs. 68 %). FDG-PET was more specific (100 % vs. 71 %) albeit less sensitive than CT-imaging (27 % vs. 73 %).
Conclusion: In our study, FDG-PET did not increase the accuracy of standard staging (CT) in patients with carcinoma of the esophagus. Therefore, no new consequences resulted for the operative indication as well as therapeutic procedure. Due to the high costs involved with PET investigation, this form of staging is momentarily indicated mainly for use in clinical studies, and in cases where CT does not offer unequivocal results. Increase in sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals as well as optimized apparatus resolution could lead to new indications for this staging procedure.