NBTXR3 and Radiation Therapy in Treating Patients With Locally Advanced SCC of the Oral Cavity or Oropharynx

Inclusion criteria: * Patients aged ≥ 70 years old, or * Patients aged ≥ 65 years old and \< 70 years old who are unable to receive cisplatin, or * Patients who have contraindication to cisplatin or that are intolerant to cisplatin or cetuximab or that cannot receive the combination of chemoradiation, regardless the age * Histologically or cytologically confirmed squamous cell carcinoma (SCC) of the oral cavity or oropharynx * T3 or T4 primary tumor or Stage III or IVA according to AJCC guidelines (8th Edition, 2018) * No evidence of distant metastatic disease, as determined by a negative PET scan or CT scan * Clinically eligible for intratumor implantation by injection * Karnofsky Performance Status ≥ 70 * Adequate function of Bone marrow: * White Blood Cell (WBC) \> 3.0 x 10\^9/L * Absolute neutrophil count (ANC) \> or = 1.0 x 10\^9/L * Platelet count \> or = 100 x 10\^9/L * Hemoglobin \> or = 9.0 g/dL * Adequate function of Kidney: o Creatinine \< or = 3.0 x ULN or creatinine clearance \> or = 30 mL/min/1.73m² * Adequate function of the liver: * AST \< or = 5 x ULN * ALT \< or = 5 x ULN * Bilirubin \< or = 1.5 x ULN * Negative pregnancy test ≤ 7 days of NBTXR3 injection in all females of child-bearing potential Exclusion Criteria: * Written Informed Consent not obtained, signed and dated * Prior radiotherapy to any area within the planned radiotherapy field * Tumor-related dyspnea * Tumor ulceration which implies vascular risk * Non measurable disease…