Study of a Strategy Integrating Adjuvant Radiation Therapy Versus Strategy Based on Monitoring in the Treatment of Carcinomas Spinocellular With High Risk of Recurrence

The goal of this clinical trial is to evaluate a strategy integrating adjuvant radiation therapy versus strategy based on monitoring in the treatment of carcinomas spinocellular with high risk of recurrence (SCC). The investigators will compare the disease-free survival (DFS) of patients treated with adjuvant radiation therapy versus surveillance in high risk of recurrence SCC. The main question it aims to answer is: Is DFS different between the "adjuvant radiotherapy" group and the "surveillance" group? Participants will: * be distributed in one of the two arms * will be followed up every 4 months for 2 years, then every 6 months (clinical examination, identification of concomitant treatments, imaging, quality-of-life questionnaire) * followed up until their death or their progression whether local, regional or metastatic