Radiotherapy alone as a method of treatment for sinonasal mucosal melanoma: A report based on six cases and a review of current opinion.

Objectives: Radiotherapy in patients with sinonasal mucosal melanoma (SNMM) was given as alternative treatment to surgery in cases with advanced, inoperable tumors or those not eligible for surgery. We presented the outcomes for patients with SNMM treated with radiotherapy alone.
Material and Methods: The retrospective review of 6 consecutive SNMM (nasal cavity - 4 pts. and paranasal sinus - 2 pts.) patients (3 males and 3 females at mean age 64 years) treated between 2008 and 2016 was presented. The stage of disease was: T3 (1 pt.), T4a (3 pts.), T4b (2 pts.); with N0 and M0 in all patients. All patients underwent definitive primary photon radiotherapy (IMRT) alone; dose 66-72 Gy was delivered in 22-24 fractions given in 5 fractions (3 Gy) a week.
Results: The complete remission was observed in all our patients but only one patient survived 5 years without disease. Five patients died due to multiple distant metastases; two of those patients developed associated local recurrence 7-8 months after radiotherapy.
Conclusion: SNMM has a poor prognosis due to its high metastatic potential. Based on our numerically small report and data from literature we concluded that primary radiotherapy alone assured complete remission and even 5-year disease-free survival in only a few individual patients.