Phase II study of proton beam therapy as a nonsurgical approach for mucosal melanoma of the nasal cavity or para-nasal sinuses.

ABSTRACT

PURPOSE: The aim of this phase II study was to assess the clinical benefit of proton beam therapy for mucosal melanoma of the nasal cavity and para-nasal sinuses. MATERIALS AND METHODS: N0M0 mucosal melanoma of the nasal cavity and para-nasal sinuses were enrolled. Proton therapy was delivered three times per week with a planned total dose of 60 GyE in 15 fractions. Primary endpoint was local control rate at 1 year after treatment. Based on the results of a pilot study, the local control rate was estimated at 75%. RESULTS: Thirty-two patients were enrolled from June 2008 through October 2012. Patient characteristics were as follows median age 73 years (range, 36-89 years); male/female ratio, 12/20; and T stage 3/4, 11/21. Local control rate at 1 year was 75.8% (95% CI 63.8-92.4%). With a median follow-up period of 36.4 months, 3-year overall survival rate was 46.1%. The most frequent pattern of first failure was distant metastasis. The main cause of death was cancer death due to distant metastases (93.3%). CONCLUSIONS: Proton beam therapy showed sufficient local control benefits for mucosal melanoma as an alternative treatment of surgery.