Abstract: Objective： To investigate clinical features of distant metastases from malignant salivary gland carcinomas after treated by 125I internal brachy therapy alone. Methods: Between 2002 and 2010, 43 patients with locally advanced unresectable or recurrent malignant salivary gland carcinomas were treated by 125I internal brachy therapy alone at Peking University School and Hospital of Stomatology. All of them had been follow-up at least 2 years. The primary sites of malignant salivary gland carcinomas were the parotid for 12 patients, infratemporal fossa for 9 patients, tongue for 7 patients, maxilla for 6 patients, parapharyngeal for 4 patients, floor of months for 3 patients, submandibular gland for 1 patient, and lip for 1 patient. The overall survival rate, local control rate, and distant metastases were retrospectively reviewed. Results: Distant metastases occurred in 23 of the 43 patients (53.5%). Distant metastases developed from 5 to 96 months, with an average interval of (27.0±23.7) months from the time of initial diagnosis, the mean interval was 21 months. The commonest site of distant metastases overall was the lung 69.6%(16/23). The most common pathological types of distant metastases were adenoid cystic carcinoma (14/23, 60.9%) and nonspecific adenocarcinoma (7/23, 30.4%). At the time of the last follow-up, 26 patients died, and 18 of them due to distant metastases (69.2%, 18/26). In the study, 27 patients got complete remission(CR), 12 got partial remission(PR) more than 50%, 2 less than 50%, and 2 patients were invalid. The effective rate (CR+ PR) was 90.7%. The 3 year loco-regional control rate and survival rate were 60.1%, 82.6%, respectively, and the 5 year’s 53.4% and 56.0%. Conclusion: The 125I brachy therapy is a feasible and effective modality for the treatment of locally advanced unresectable or recurrent malignant salivary gland carcinomas. However, further studies are needed with larger numbers of patients and for a longer follow-up assessment. Distant metastasis was the main cause of treatment failure, and the lung was the most common site of distant metastases.

Key words: Head and neck neoplasms, Salivary gland neoplasms, Neoplasm metastasis, Brachy therapy, Iodine radioisotopes