Postoperative radiation therapy for parotid mucoepidermoid carcinoma

Salivary gland cancers are rare and represent approximately 5% of all head and neck cancers and only 0.3% of all malignancies. The majority (75%) of salivary gland tumors occur in the parotid gland, and while benign lesions are more common, mucoepidermoid carcinoma (MEC) makes up 40-50% of malignant parotid gland tumors. No randomized controlled trials exist regarding the role of adjuvant radiation for patients who undergo surgical resection of low-grade MECs. Herein, we report two cases of successful postoperative radiation therapy in low-grade, pT2N0 MEC of the parotid gland. The role of adjuvant radiation therapy for patients with MEC of the parotid gland is based on data from institution reviews and lacks data from randomized controlled trials. Per our review of the literature, the pathological findings of positive surgical margins and/or perineural invasion in two patients with low-grade MEC of the parotid gland warranted adjuvant radiation for improved local control after partial parotidectomy. Both patients tolerated postoperative radiation therapy with only mild side effects and, at last follow-up, five years after completion of therapy, had no clinical or radiographic evidence of either local recurrence or distant metastasis.