Proton Beam Therapy for Ameloblastic Carcinoma of the Maxilla: Report of a Rare Case

Ameloblastic carcinoma (AC) is a rare malignant odontogenic tumor that combines the histologic features of ameloblastoma with those of cytologic atypia. The standard treatment for this lesion is wide local excision. Proton beam therapy (PBT) can deliver high irradiation doses to the target and avoid irradiation to surrounding normal tissues, but no reports of PBT for AC have been published thus far. This report describes the case of a 70-year-old woman with a pathologic diagnosis of maxillary AC who refused surgical resection and received hypofractionated PBT at a total dose of 69 Gy in 23 fractions. She has been alive for more than 5 years after PBT without any evidence of recurrence and side effects. This is the first reported case of successful treatment after curative radiation therapy for maxillary AC.