PET-CT scan in the preoperative workup of early stage intermediate- and high-risk endometrial cancer

Objectives: To evaluate positron emission tomography-computed tomography (PET-CT) for the preoperative management of early-stage intermediate- and high-risk endometrial cancer (EC). Study design: Data of patients with intermediate- and high-risk early-stage EC were retrieved from a prospectively collected database. Patients with preoperative PET-CT followed by surgical staging including pelvic lymphadenectomy were analyzed. Diagnostic performance for lymph node (LN) metastasis was evaluated. Results: Overall, 45 patients were included: 27 (60%) and 18 (40%) with intermediate- and high-risk EC, respectively. Four patients (8.8%) had LN metastasis, three correctly identified at PET-CT, yielding a sensitivity of 75% (95% CI 21.9-98.7). Among 41 patients (91.2%) without LN metastasis, 38 had negative PET-CT with specificity of 92.7% (95% CI 78.9-98.1). The negative predictive value (NPV) was 97.4% (95% CI 84.9-99.9) and the positive predictive value was 50% (95% CI 13.9-86.1). Conclusions: The utility of PET-CT is limited by the low sensitivity for LN metastasis in intermediate- and high-risk early-stage EC, that may impede to consider PET-CT alone an adequate alternative to surgical retroperitoneal staging by lymphadenectomy or sentinel LN biopsy. However, the high diagnostic accuracy, specificity and NPV might support its adoption to improve the diagnostic accuracy of the sentinel LN algorithm.