Comprehensive Treatment for Major Salivary Gland Carcinoma Based on Intensity-Modulated Radiotherapy with or without Radical Surgery

Abstract

Background The present study aimed to determine a treatment strategy and Intensity-Modulated Radiotherapy (IMRT) target volume for major salivary gland carcinoma (SGC). Methods Patients with SGC treated at our cancer center between August 2009 and August 2020 were retrospectively reviewed. Results The following primary tumor sites were identified: parotid gland in 61 (69.3%) patients, submandibular gland in 21 (23.9%) patients, and sublingual gland in six (6.8%) patients. Lymphoepithelial carcinoma (LEC) was the most common tumor subtype that accounted for 23.9% of cases. A total of 80 (90.9%) patients received radical surgery combined with postoperative radiotherapy. Eight patients (9.1%) received definitive radiotherapy: six patients with advanced-stage disease received induction chemotherapy (IC) combined with concurrent chemoradiotherapy (CCRT), and two patients with early-stage disease received CCRT. Complete response was observed in these eight patients after treatment completion. The median follow-up time of all patients was 42 months (range: 4–129 months). No patient developed local recurrence. The 5-year overall survival, regional failure-free survival, distant metastasis-free survival, and progression-free survival probabilities were 84.1%, 95.6%, 75.3%, and 75.7%, respectively. Distant metastasis was observed in 18 (20.5%) patients, followed by regional 2 (2.3%) recurrence. Permanent facial nerve injury was confirmed in 31 patients by follow-up. None of the patients experienced facial nerve paralysis in the definitive radiotherapy group. Conclusions LECs may be sensitive to chemoradiotherapy, which may achieve a radical effect and avoid unnecessary surgical injury. IC combined with CCRT is expected to become a new treatment strategy for advanced LECs. The IMRT target volume delineation according to the surgical principles may be a more promising method with good clinical efficacy that is worthy of further study.