Prospective Clinical Study to Identify Secondary Sentinel Lymph Nodes in Patients With N1/N2b Oral Cavity or H&N Skin Cancers Using Patent Blue V and Indocyanine Green Dyes

Inclusion Criteria: 1. Age ≥18 years 2. Operable SCC located in the oral cavity or the skin of the H\&N region, with one or two LNM 3. Primary disease 4. ECOG performance status 0-2 5. Signed study informed consent form for participation Exclusion Criteria: 1. Non-operable tumors or contraindication to surgery 2. Previously treated head and neck cancer. Note: neoadjuvant treatment is not an exclusion criterion 3. Known hypersensitivity/allergy to triphenylmethane-based (Blue) dyes or to any of their components 4. Known hypersensitivity/allergy to indocyanine green or sodium iodide or iodine 5. Patients with known hyperthyroidism, thyroid autonomy (e.g., autonomous adenoma), or any thyroid disorder that may lead to increased iodine uptake 6. Patients with severe renal impairment (e.g., estimated glomerular filtration rate \<30 mL/min/1.73 m²) 7. Patients receiving beta-blocker therapy, as these medications may mask or reduce the response to anaphylactic reactions induced by dye injection 8. Pregnancy and/or ongoing breastfeeding 9. Any reason that would interfere with the patient's well-being and treatment as assessed by the investigator