Induction chemotherapy with docetaxel and doxorubicin followed by proton beam radiation therapy for platinum-resistant unresectable sinonasal undifferentiated carcinoma

Sinonasal undifferentiated carcinoma is a rare and aggressive tumor with an extremely poor prognosis. In the vast majority of cases, this tumor can not be resected due to its rapid local growth. Correct morphological diagnosis is impossible without a thorough differential diagnosis between sinonasal undifferentiated carcinoma and a number of lowgrade tumors of the nasal cavity and paranasal sinuses. Very few case reports and retrospective studies on sinonasal undifferentiated carcinoma have been published so far. No unified widely accepted guidelines on sinonasal undifferentiated carcinoma treatment are currently available due to the lack of statistically significant data from randomized clinical trials. The optimal treatment strategy should be based on an aggressive multimodal approach involving radical surgery, precision radiation therapy, and intensive chemotherapy. The benefits of systemic targeted therapy for patients with sinonasal undifferentiated carcinoma are still unclear. The best results can be achieved by employing tailored treatment approaches preferably in multidisciplinary cancer centers, where healthcare professionals experienced in managing patients with head and neck tumors can be involved. In this article, we report a case of complete radiological response after induction chemotherapy with docetaxel and doxorubicin and proton radiation therapy for the primary tumor area in a 53‑year-old female patient with non-resectable platinum-resistant sinonasal undifferentiated carcinoma.