Omitting Therapeutic Lymph Node Dissection in Patients With Melanoma (Stage 3) and Major Pathological Response in the Index Lymph Node

Inclusion Criteria: * Patients must be eligible for neoadjuvant treatment (ipilimumab and nivolumab) * Patients must be 16 years of age or older. * Patients must have a histologically confirmed diagnosis of macroscopic resectable stage III melanoma (stage III B/C/D) with one or more macroscopic lymph node metastase defined as either one: * a palpable node, confirmed as melanoma by pathology; a non-palpable but enlarged lymph node according to RECISTv1.1 (at least 15 mm in short axis), confirmed as melanoma by pathology; * a PET scan positive lymph node of any size confirmed as melanoma by pathology; * The patient must have a measurable tumor burden that qualifies (according to clinical practice) for neoadjuvant therapy with immune checkpoint inhibitors * Patients in whom ILN marking is feasible * Written informed consent Exclusion Criteria: * Uveal/ocular or mucosal melanoma * WHO performance status of two or more * In-transit metastases only (without cytological or histological proven lymph node involvement) * Prior targeted therapy targeting BRAF and/or MEK for melanoma * Prior immunotherapy targeting CTLA-4, PD-1 or PD-L1 for melanoma * Patients with (history of) distant metastasis (stage IV melanoma)