The standard treatment approach for localised Merkel cell carcinoma (MCC) is wide surgical excision followed by adjuvant radiotherapy. However extensive surgery for locally advanced MCC may cause morbidity and disfigurement, compromise function and delay adjuvant therapy. Since MCC is a highly radiosensitive tumour, an alternative treatment option for advanced MCCs, especially those in anatomically challenging locations, is radiotherapy. Complete and durable control is achieved in up to 90% of cases if the definitive treatment of primary MCC is with radiotherapy. It is generally less morbid than surgery and can produce excellent cosmetic and functional outcomes.

https://www.sciencedirect.com/science/article/abs/pii/S0748798320304856