18FDG-PET-CT improves specificity of preoperative lymph-node staging in patients with intestinal but not diffuse-type esophagogastric adenocarcinoma.
BACKGROUND
The accuracy of preoperative lymph-node staging in patients with adenocarcinoma of the esophagogastric junction (AEG) or gastric cancer (GC) is low. The aim of this study was to assess the accuracy of [18F]fluorodeoxyglucose positron emission tomography/computed tomography (PET-CT) for lymph-node staging in patients with AEG or GC, with or without neoadjuvant treatment.


METHODS
221 consecutive patients with GC (n = 88) or AEG (n = 133) were evaluated. Initial staging included endoscopic ultrasound (EUS), multidetector spiral CT (MDCT) and PET-CT. PET-CT was performed for restaging in patients after neoadjuvant treatment (n = 94). Systematic lymphadenectomy was routinely performed with histopathological assessment of individual mediastinal and abdominal lymph-node stations. Preoperative staging from EUS, MDCT, and PET-CT was correlated with histopathological results.


RESULTS
PET-CT showed a high specificity (91%) and positive predictive value (89%) for the preoperative detection of lymph-node metastases. In comparison, EUS was more sensitive (73% versus 50%, P < 0.01) but less specific (60%, P < 0.01). In patients with intestinal/mixed-type tumors, PET-CT improved the detection of extra-regional lymph-node metastases (P = 0.01) and distant metastases (P = 0.01) compared to CT alone. In contrast, lymph-node assessment by PET/CT after neoadjuvant treatment (32%, P < 0.01) and in diffuse-type cancers (24%, P < 0.01) is futile because of low sensitivities.


CONCLUSIONS
PET-CT does not improve the overall accuracy of N staging, but does improve specificity compared to EUS and MDCT in AEG and GC. We do not recommend routine PET-CT for the initial staging in patients with diffuse-type cancer or for restaging of lymph nodes after neoadjuvant treatment.
Department of Visceral and Transplantation Surgery, University Hospital Zurich, Switzerland.
K
K
Lehmann
Department of Visceral and Transplantation Surgery, University Hospital Zurich, Switzerland.
D
D
Eshmuminov
Department of Gastroenterology, University Hospital Zurich, Switzerland.
P
P
Bauerfeind
Department of Gastroenterology, University Hospital Zurich, Switzerland.
C
C
Gubler
Department of Nuclear Medicine, University Hospital Zurich, Switzerland.
P
P
Veit-Haibach
Institute of Clinical Pathology, University Hospital Zurich, Switzerland.
A
A
Weber
Department of Visceral and Transplantation Surgery, University Hospital Zurich, Switzerland.
H
H
Abdul-Rahman
Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland.
M
M
Fischer
Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland.
C
C
Reiner
Surgical Center Zurich for Visceral, Thoracic and Specialized Tumor Surgery, Hirslanden Medical Center, Zurich, Switzerland. Electronic address: paul@professor-schneider.ch.
P M
PM
Schneider
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D003287:Contrast Media; D019160:Endosonography; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D004943:Esophagogastric Junction / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography; D011237:Predictive Value of Tests; D057234:Preoperative Period; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
Gastric cancer; PET-CT; Preoperative staging