• Age greater than or equal to (\>=) 60 years old

• Squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or supraglottic larynx and a candidate for definitive radiation therapy with or without cetuximab

• Clinical stage T3-4 NX or T2 N2-3 disease according to the 8th edition of AJCC

• One primary tumor lesion amendable for intratumoral injection

• Ineligible to receive platinum-based chemotherapy with radiation (at least one of the following):

‣ Estimated creatinine clearance \>= 30 and less than (\<) 50 milliliters/minute (mL/min) (per Cockcroft-Gault equation), Grade \>= 2 hearing loss or tinnitus, Grade \>= 2 peripheral neuropathy, Eastern Cooperative Oncology Group (ECOG) Performance Status 2 or New York Heart Association Class 3

⁃ Age 70-74 years old with Geriatric 8 (G8) score less than or equal to (\<=) 14

⁃ Age \>= 75 years old