Feasibility and Safety of CareMin650 in Patients at Risk of or Suffering From Oral Mucositis and/or Radiation Dermatitis

Inclusion Criteria: Inclusion Criteria common to both cohorts: * Adult patients (age ≥18 years) accepting to participate in the study and having signed the written informed consent form prior to any protocol-specific procedures. * Having an ECOG (Eastern Cooperative Oncology Group) performance status ≤ 2. * Having a life expectancy greater than 3 months according to the investigator medical judgement. * Having the ability to understand and sign the written informed consent form and willing to comply with protocol requirements. Specific criteria for inclusion in head and neck cancer cohort (cohort A): * Patient with histologically proven squamous cell carcinoma of oropharynx, nasopharynx, hypopharynx, larynx or oral cavity with or without prior surgical resection * Patient with dental examination prior to chemo-radiotherapy and any required dental treatment performed * In cohort A1 (patient with no oral mucosa or skin lesion, starting radiotherapy), patient scheduled to receive intensity modulated radiation therapy on at least 50% of the oral mucosa at a total dose of at least 40 Gy, alone or associated with chemotherapy or targeted therapies. * In cohort A2, (on-going radiotherapy), presence of oral mucositis and/or radiation dermatitis grade 1, 2 or 3. Specific criteria for inclusion in breast cancer cohort (cohort B) * Patient with histologically proven breast cancer * After breast-conserving surgery, or total mastectomy if the patient is at high risk of radiodermatit…