Efficacy of surgery combined with postoperative 125I interstitial brachytherapy for treatment of acinic cell carcinoma of the parotid gland in children and adolescents

Abstract

Background Acinic cell carcinoma (AciCC) is rare in children; therefore, reaching a consensus on its management is challenging and radiotherapy is limited by concerns about long-term toxicity. The purpose of this study is to analyze the effectiveness and safety of surgery plus postoperative I-125 interstitial brachytherapy (IBT) for children and adolescents with AciCC of the parotid gland (PG) treated at a single institution. Procedure Sixteen patients <= 18 years old with AciCC of the PG treated with surgery plus I-125 IBT from 2007 to 2018 were included. Surgery was the primary treatment; ten patients underwent total gross excision and six subtotal gross excision. The matched peripheral dose was 60-120 Gy. Overall survival, disease-free survival (DFS), local control rate, distant metastasis, and radiation-associated toxicities were analyzed, and factors influencing outcomes were evaluated. Results During follow-up (1.8-12.6 years; mean, 6.3 years), lymph node metastasis was observed in one case, 2.6 years after I-125 IBT treatment. The five-year overall and DFS rates were 100% and 91.7%, respectively. On univariate analysis, tumor size >= 3 cm (100% vs 50%; P = 0.025) and extraglandular extension (100% vs 50%; P = 0.025) were significant prognostic indicators for DFS. No severe radiation-associated complications occurred. Conclusions Children and adolescents with AciCC of the PG with high-risk features can be managed using surgery plus postoperative I-125 IBT with excellent local control. Radiation-related complications were minor. Patients with facial nerve involvement can have their facial nerves preserved. Residual tumors can be safely managed using adjuvant I-125 IBT.