Keywords: CT, computed tomography; HNCSCC, head and neck cutaneous squamous cell carcinoma; IMRT, intensity-modulated radiation therapy; MMS, Mohs micrographic surgery; PNI, perineural invasion; RT, radiation therapy; SCC, squamous cell carcinoma; adjuvant therapy; cutaneous squamous cell carcinoma; iatrogenic immunosuppression; organ transplantation; radiation therapy; skin cancer.