The diagnostic accuracy of fluorodeoxyglucose-positron emission tomography/computed tomography and sentinel node biopsy in the prediction of pelvic lymph node metastasis in patients with endometrial cancer

According to the sentinel node biopsy (SNB), systematic pelvic lymph node dissection (PLND) may not be needed for patients with early-stage endometrial cancer. On the other hand, imaging technology including fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) has been developing worldwide. The aim of this study was to evaluate the combined diagnostic accuracy of FDG PET/CT and SNB in the prediction of pelvic lymph node metastasis in endometrial cancer patients.One hundred twenty-one patients with endometrial cancer underwent FDG PET/CT before hysterectomy and received SNB followed by systematic PLND. Univariate and multivariate analyses were performed to compare the diagnostic accuracy of FDG PET/CT and SNB in the prediction of pelvic node metastasis to the ultimate histologic status.FDG PET/CT had lower sensitivity (36.8% versus 57.9%, P = .1) and a higher specificity (96.4% versus 84.8%, P < .01) than SNB. The kappa statistics of FDG PET/CT and SNB were 0.37 (95% CI, 0.15-0.59) and 0.72 (95% CI, 0.53-0.90), respectively. The sensitivity of SNB was significantly higher than that of FDG PET/CT in all hemi-pelvises (HPs) in which the short axis of the largest metastatic lymph node was <5 mm in diameter (72.7% versus 18.2%, P = .01). In contrast, the sensitivity of FDG PET/CT was higher than that of SNB in all HPs in which the short axis of the largest metastatic lymph node was ≥5 mm in diameter (62.5% versus 37.5%, P = .2); however, the difference was not statistically significant. When the combined diagnosis of FDG PET/CT and SNB was made, the sensitivity and specificity were 84.2% and 82.1%, respectively.SNB was more useful for detecting lymph node metastasis than FDG PET/CT, especially in patients with small metastatic lymph nodes. The combined diagnosis of FDG PET/CT and SNB improves the sensitivity; PET-positive nodes should be dissected regardless of SNB status and HPs in which SNB was not detected should be dissected systematically regardless of FDG PET/CT status.