Perineural invasion and parotid involvement in auricular cutaneous SCC: Which volumes to treat in postoperative radiotherapy?

INTRODUCTION: Postoperative radiotherapy is recommended for all patients with cutaneous and non-cutaneous squamous cell carcinoma of the head and neck in the presence of clinical and incidental perineural infiltration. Perineural infiltration represents one of the most important adverse prognostic factors and may impact negatively patient outcomes. While guidelines exist for defining radiotherapy treatment volumes in patients with cutaneous squamous cell carcinoma and clinical perineural infiltration, there is a notable gap in the literature regarding recommendations for cases with incidental perineural infiltration and parotid involvement. METHODS: A case of cutaneous squamous cell carcinoma of the auricular zone was proposed to an expert radiation oncologist panel. RESULTS: The main issues concerned the inclusion of the surgical bed alone or the extension to the adjacent zone. CONCLUSION: This paper aims to provide a review of literature data and to propose a comprehensive approach to target volume definition in this setting of patients.