Clinical Research Directory

Inclusion Criteria: * Patients ≥ 18 years of age at the time of signing informed consent to participate; * Patient with histologically confirmed, localized skin squamous cell carcinoma; Note bene: patients with carcinoma of the external auditory canal may be included in the study; * Patient treated with complete excision surgery (R0), regardless of margin (inframillimetric or supramillimetric); * High risk disease defined by: presence of a microscopic PNI without/with another risk factor (among those mentioned below) OR presence of 2-3 risk factors other than microscopic PNI; Note Bene: The risk factors selected are immunosuppression (only haematopathy with or without treatment) , a tumor diameter \>20mm, specific location (lip/ear/temple), deep invasion (thickness \>6mm or invasion beyond subcutaneous fat), low differentiation or desmoplasia; * Patient informed and having signed consent to participate in the study; * Patient affiliated with a health insurance plan (or beneficiary of such a plan). Exclusion Criteria: * Patient with in situ or mixed SCC; * History of SCC at high risk of relapse in the same territory (head and neck, trunk or limb) in the 2 years preceding the date of randomization; * History of SCC having received systemic treatment; * Patient with SCC located in the endonasal, intra-oral, anogenital or vulvar mucosa; * Patient with recurrent SCC or SCC at very high risk of relapse defined by one of the following criteria: * PNI with \> 2 other risk factors, * \> 3 risk factors, * bone invasion, * immunosuppression by immunosuppressive treatments (whatever the reason). * Patient with SCC with a single risk factor other than PNI; * Patient with SCC with lymph node or distant metastasis; * Patient with a history of solid cancer undergoing chemotherapy; * Patient with a contraindication to radiotherapy; * Patient with a history of radiotherapy in the area of the lesion; * Participation in another clinical trial that may interfere with the assessment of the primary endpoint; * Patient under guardianship or curatorship or deprived of liberty; * Pregnant or breastfeeding woman.