Epithelial ovarian cancer (EOC) is detected at an early stage in up to 20% of patients, requiring complete staging surgery to assess peritoneal or lymph node involvement, to determine prognosis and appropriate adjuvant therapy [1]. Although systematic pelvic and para-aortic lymphadenectomy is part of the staging surgery for early-stage EOC [2,3], the incidence of lymph node metastasis is approximately 15–20%. Lymphadenectomy is an invasive and laborious procedure that can lead to intra-operative and post-operative complications, adversely affecting the patient's quality of life. Therefore, the prognostic value of full lymph node dissection must be carefully balanced against the associated morbidity, particularly the risk of lower-leg lymphedema. [4,5] Moreover, no evidence suggests that full lymph node dissection has any added therapeutic value [6].

In recent decades, sentinel lymph node (SLN) mapping has emerged as an alternative to lymph node dissection and has been incorporated into surgical treatment for other gynecologic malignancies to reduce associated morbidity [7,8]. Furthermore, comprehensive evaluation of the SLNs through ultrastaging and immunohistochemical analysis improves the detection of low-volume disease [9]. However, the role of SLN mapping in managing early-stage EOC is still under investigation. Previous studies [[10], [11], [12]] have demonstrated the feasibility and safety of SLN mapping in early-stage EOC. Nevertheless, several key questions regarding the technique, including aspects such as the choice of tracers and injection site selection, as well as detection outcomes, still lack conclusive answers. Findings from a recent meta-analysis [13] aknowledge the limited quality of existing evidence and underscore the necessity for further studies and evaluation before implementing SLN mapping as routine clinical practice.

We conducted the Mapping Sentinel Lymph Nodes In Early-Stage Ovarian Cancer (MELISA) trial, a prospective study designed to evaluate the SLN detection rate and the diagnostic accuracyof SLN mapping in patients with early-stage EOC, compared with the reference standard of complete pelvic and para-aortic lymphadenectomy.