Do Positive PET/CT Scans for Esophageal Disease Preclude Endoscopic Treatment of Early Esophageal Adenocarcinoma?

Purpose: CT-fusion positron emission tomography (PET/CT) with fluorine 18 fluorodeoxyglucose (FDG) has been increasingly applied for staging of patients with esophageal adenocarcinoma (EAC) for its detection of regional and distant metastases (LNM); however, the role of PET/CT scan in identifying candidates who are suitable for endoscopic therapy (≤ T1a stage) is still unknown. Our initial hypothesis was that the volume of tumor necessary to be positive in the esophagus could preclude endoscopic therapy due to the size and depth of invasion. The aim of this study was to evaluate the association of positive esophageal PET/CT scans and depth of tumor invasion based on histopathology. Methods: PET/CT scan and pathology reports of consecutive EAC patients who underwent endoscopic mucosa resection (EMR) were reviewed. Patients with abnormal uptake in celiac and abdominal lymph node or the presence of distant lesions on PET scans were excluded. A negative PET was defined as no abnormal uptake, while positive PET scans have, visible esophageal thickness or mass in PET/CT fused imaging with a SUV > 3. Indefinite PET scan cases included those who lack of typical uptake pattern such that it is impossible to differentiate inflammation from malignancy. The depth of EAC invasion was categorized as either T1a (intramucosa), T1b (submucosa), T2 (muscularis propria), or T3 (adventitia) based on either EMR or esophagectomy histopathology reports. Results: Totally 130 eligible EAC patients from 2000 to 2010 were identified. All had PET/CT scans performed within 6 months of the index EMR that found EAC. 60 cases had negative PET; 30 were positive; and 40 were indeterminate, of which 45% (18/40) had lesions ≤ T1a stage. After excluding these 40 indeterminate cases, the final analyses were based on 90 cases. The mean age was 69.4 ± 12.0 years; 86.7% were male; 23 had esophagectomy. 27 (28.9%) were T1a; 49 were T1b; 12 were T2 and 2 were T3. And 30 (33.3%) had positive PET scan. 60 (66.7%) had negative PET scan. Among 30 cases with positive PET/CT results, 30.0% (9/30) had T1a lesions. 33.3% of patients had positive PET scans in both T1a and ≥T1b groups. Overall PET scan results were not associated with T staging based on pathology findings. There was no difference in age (> 70 y/o), gender, and rate of esophagectomy between the positive and negative PET scan cases. Conclusion: Positive esophageal CF-fusion PET scans do not indicate a tumor bulk that precludes endoscopic mucosal resection for the treatment of early esophageal cancer. Disclosure: Dr. GA Prasad: Takeda (research support); Lori S. Lutzke: Olympus, Fujinon, Barrx (research support); Dr. Wong Kee Song: Olympus (consulting and research support); Dr. Kenneth K. Wang: Olympus (research support), Nine Points Medical (consulting), Oncoscope (advisory board), Fujinon (research support), Barrx (research support).Table: Comparison of PET/CT results and histology from endoscopic mucosal resection or esophagectomy specimens