Recurrent pleomorphic adenoma of the parotid gland: Long-term outcome of patients treated with radiation therapy

Purpose: To evaluate the role of radiation therapy in the management of recurrent pleomorphic adenoma of the parotid gland. Methods and Materials: Between 1960 and 2004, 34 patients were treated with postoperative radiation therapy for recurrent pleomorphic adenoma of the parotid gland to a median dose of 5000 cGy (range, 4,500-6,000 cGy). Median age was 48 years (range, 24-72 years). Gross total resection at the time of surgery before radiation was achieved in 30 patients (88%), and histologic analysis demonstrated multifocal disease in 16 patients (47%). Radiation was delivered for a first, second, third, fourth, fifth, and sixth local recurrence in 24%, 21%, 24%, 24%, 6%, and 3% of patients, respectively. Results: With a median follow-up of 17.4 years (range, 2.3-28.9 years), 2 patients had local recurrences at a median of 3.4 years after completion of radiation. The 20-year actuarial local control rate was 94%. One patient developed a second malignancy at approximately 14 years after completion of therapy. Conclusion: The use of postoperative radiation therapy leads to excellent long-term local control for the treatment of recurrent pleomorphic adenoma with acceptable late toxicity. Although the incidence of second malignancy was low in this population, continued follow-up is warranted.