[Distant metastases of malignant salivary gland carcinoma after treated by 125 I].

OBJECTIVE: To investigate clinical features of distant metastases from malignant salivary gland carcinomas after treated by 125 I internal brachy therapy alone.

METHODS: Between 2002 and 2010, 43 patients with locally advanced unresectable or recurrent malignant salivary gland carcinomas were treated by 125 I 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 125 I 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.