Proton Beam Therapy as a Curative Treatment for a Young Case of Unresectable Tracheal Adenoid Cystic Carcinoma.

Primary tracheal adenoid cystic carcinoma (TACC) is a rare malignancy without an established treatment. Central airway obstruction due to TACC often decreases the quality of life and has life-threatening consequences. A 19-year-old man with unresectable TACC and central airway obstruction suffered from progressive cough and dyspnea after exercise. Proton beam therapy (PBT) was selected as the preferred treatment over systemic anti-cancer chemotherapy for TACC. PBT led to complete remission of TACC and the almost complete disappearance of the respiratory symptoms without adverse events. PBT is a useful and safe treatment for unresectable primary TACC.