Background: The use of [18F]flourodeoxyglucose positron emission tomography (FDG-PET) as an adjunct to computerized tomography (CT) and endoscopic ultrasound (EUS) in the staging of esophageal carcinoma has increased. FDG-PET has been shown to have an increased sensitivity for identifying distant metastases over CT and EUS, however it is not known how often this additional information alters the clinical decision avoiding major surgical resections and its associated morbidity for patients who are unlikely to benefit. The purpose of this study is to evaluate the influence of FDG-PET on the decision to operate in patients undergoing a staging work up for distal esophageal carcinoma.
Methods: A review of patients with distal esophageal carcinomas who were staged preoperatively with FDG-PET in addition to standard screening with CT or CT and EUS to determine if the use of FDG-PET significantly changed the decision to perform a curative operation. Patients who were restaged after the administration of neoadjuvant or primary chemoradiotherapy were reviewed to determine if the change in the intensity of FDG uptake in primary lesions, using the standardized uptake value (SUV), correlated with response to therapy and survival for its potential use in estimating prognosis.
Results: Of the 53 patients who had were considered for surgery based on traditional staging methods including CT and EUS, 10 (19%) had findings on FDG-PET that precluded surgical intervention. 36 patients who had PET scans before and after CRT were evaluated based on the effect of therapy on SUV. A reduction in SUV by greater than 50% resulted in recurrence in 9 of 23 (39%) patients whereas a less than 50% reduction in SUV resulted in 10 of 13 (77%) patients (p<0.05, RR=2.6, 95% CI 0.92 to 7.53) recurring over an average follow-up period of 23 months. Interestingly, of the patients that did develop recurrent disease, the patients with larger reductions in SUV tended to succumb to their disease more rapidly than patients that recurred who had smaller reductions in SUV.
Conclusion: The use of FDG-PET in the staging of patients with esophageal carcinoma saves nearly 20% of patients from undergoing a morbid surgical procedure unnecessarily. Additionally, A large reduction in SUV after CRT selects a group of patients that have a significantly better prognosis. PET scan should become a routine elemet in the preoperative evaluation of esophageal carcimoma and repeat PET after CRT may become an important prognostic indicator.