Definitive Radiotherapy for Locally Advanced Merkel Cell Carcinoma of the Head and Neck Region: A Case Report.

Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine malignancy of skin origin. It is most commonly managed with upfront surgical resection which is then followed by radiotherapy as soon as possible postoperatively. Radiotherapy alone has been used in inoperable cases and in cases of patient preference to omit surgical management. MCC is a very radiosensitive disease, and an ideal location for definitive radiotherapy is the head and neck region (which represents the majority of cases), where resection often leads to reduced outcomes given the number of critical structures in the region and the inability of surgery to achieve the excision margins required for the aggressive nature of the disease without leading to severely impacted cosmesis and function. This case study looks at an elderly woman who was treated with definitive dose fractionation (to a total dose of 60 Gray in 30 fractions) radiotherapy to the head and neck region for Stage III, T1N2M0 disease, following rapid loco-regional relapse after surgical wide local excision. Two years postdefinitive radiotherapy, she has had complete loco-regional control both clinically and radiologically.