A Case of Buccal Mucosal Cancer with Function Preserved by Mold Irradiation

Abstract

Surgical resection or brachytherapy has been used for curative treatment of oral cancer. Although only limited facilities perform brachytherapy, treatment results are as good as those of surgical resection and allow functional preservation. We report here the use of high-dose-rate brachytherapy with a remote after-loading system for mold irradiation for buccal mucosal cancer, in which function is expected to be impaired by surgical treatment. The patient was a woman in her 80s who visited a dental clinic complaining of pain in the left buccal mucosa. She was referred to our department, where a tumor with a rough surface of 39 mm×22 mm was found on the left buccal mucosa. Computed tomography showed a contrast-enhanced soft-tissue mass on the left cheek, with a thickness of 20 mm. Subsequent biopsy of the lesion revealed squamous cell carcinoma, and the tumor was classified as cT2N0M0 （stage Ⅱ）. Surgical resection would be expected to cause dysfunction through the skin on the cheek, therefore simultaneous chemoradiotherapy was planned. The thickness of the oral mucosa should be less than 15 mm, but was 20 mm in this case, making brachytherapy unsuitable. We therefore created a mold device using the occlusion plate to extend the buccal mucosa and maintain contact with the source of radiation, allowing irradiation of the tumor. Mold irradiation was performed using 192-Ir at a total dose of 60 Gy. The patient remains recurrence-free as of 2 years 6 months after mold irradiation.