Sentinel lymph node (SLN) mapping may replace staging radical pelvic lymphadenectomy in women with early-stage cervical cancer. In a national multicenter setting, we evaluated SLN mapping in women with early-stage cervical cancer and investigated the accuracy of SLN mapping and FDG-PET/CT in tumors >20 mm.

We prospectively included women with early-stage cervical cancer from March 2017-January 2021 to undergo SLN mapping. Women with tumors >20 mm underwent completion pelvic lymphadenectomy and removal of FDG-PET/CT positive nodes. We determined SLN detection rates, incidence of nodal disease, sensitivity and negative predictive value (NPV) of SLN mapping, and the sensitivity, specificity, NPV, and positive predictive value (PPV) of FDG-PET/CT.

We included 245 women, and 38 (15.5%) had nodal metastasis. The SLN detection rate was 96.3% (236/245), with 82.0% (201/245) bilateral detection. In a stratified analysis of 103 women with tumors >20 mm, 27 (26.2%) had nodal metastases. The sensitivity of SLN mapping adhering to the algorithm was 96.3% (95% CI 81.0-99.9%) and the NPV 98.7% (95% CI 93.0-100%). For FDG-PET/CT imaging the sensitivity was 14.8% (95% CI 4.2-33.7%), the specificity 85.5% (95% CI 75.6-92.5%), the NPV 73.9% (95% CI 63.4-82.7%), and the PPV 26.7% (95% CI 7.8-55.1%).

SLN mapping seems to be an adequate staging procedure in early-stage cervical cancer tumors ≤20 mm. In tumors >20 mm, SLN mapping is highly sensitive but demands full adherence to the SLN algorithm. We recommend completion pelvic lymphadenectomy in tumors >20 mm until the oncological safety is established. FDG-PET/CT for nodal staging of women with early-stage cervical cancer seems limited.