Palatal Island Flap With Adjuvant Radiotherapy for Hard Palate Adenoid Cystic Carcinoma: 2-year Outcomes.

Adenoid cystic carcinoma (ACC) of the minor salivary glands most commonly arises in the hard palate and exhibits perineural invasion, indolent growth, and late recurrence, often requiring multimodal therapy. Reconstruction must restore oronasal separation, speech, and deglutition; data regarding the tolerance of palatal island flaps to postoperative radiotherapy and long-term functional outcomes remain limited. A 35-year-old woman with T1N0M0 ACC of the right hard palate (American Joint Committee on Cancer, 8th edition) underwent wide local excision with partial palatal ostectomy followed by reconstruction using a contralateral palatal island flap. After complete mucosal healing, adjuvant intensity-modulated radiotherapy (66 Gy in 33 fractions) was administered. Two-year outcomes were assessed using Thai-language validated versions of the EORTC QLQ-C30, EORTC QLQ-HN43, FACT-H&N, and UW-QOL questionnaires. Final pathology demonstrated cribriform and tubular ACC with perineural invasion. The tumor approached the medial (0.4 mm) and lateral (1.7 mm) margins, which were close but uninvolved. Acute toxicity consisted of grade 2 donor-site oral mucositis treated with topical triamcinolone. At 2-year follow-up, surveillance with magnetic resonance imaging of the skull base, computed tomography of the chest, and bone scintigraphy demonstrated no evidence of locoregional recurrence or distant metastasis. Speech was fully intelligible on speech-language pathology assessment, the Functional Oral Intake Scale score was 7, and quality-of-life outcomes remained favorable across all instruments. This case suggested that a palatal island flap may tolerate adjuvant radiotherapy when irradiation is delivered after complete flap healing, with favorable oncological, functional, and quality-of-life outcomes at 2 years.