Clinical Analysis Of Patients With Malignant Salivary Gland Tumors Treated With Surgery And Postoperative Intensity Modulated Radiotherapy

Purpose:The aims of this study were to investigate the oncological outcomes,prognostic factors,patterns of failure and the adverse events of patients with malignant salivary gland tumors treated with surgery and postoperative intensity modulated radiotherapy(IMRT).Methods:We retrospectively studied 60 patients with malignant tumors of the major salivary gland treated with surgery followed by postoperative IMRT.Data were analyzed for overall survival(OS),progression-free survival(PFS),locoregional relapse-free survival(LRRFS),distant metastasis-free survival(DMFS)prognostic factors and patterns of failure,as well as treatment-related toxicities.Results:With a median follow-up of 55.5 months,OS and PFS of the patients at 3,5,10 years were 90.7%,85.1%,85.1% and 80.1%,72.7%,63.1%,respectively.LRRFS and DMFS at 3,5,10 years were 87.4%,82.1%,82.1% and 85.3%,78.4%,66.1%,respectively.A Cox proportional hazards regression model identified N stage(P=0.047), major nerve involvement(P=0.034),positive margin(P=0.036)and interval from surgery to RT(P=0.036)as independent predictors of PFS.Positive margin(P=0.026)was a significant prognostic factor for LRRFS,and major nerve involvement(P=0.008),positive margin(P=0.011)and interval from surgery to radiotherapy(RT)(P=0.012)were correlated significantly with DMFS.The most common acute and late adverse events were mucositis,dermatitis and xerostomia.Distant metastasis was the most common pattern of failure,with the most frequent site being the lungs.Conclusion:N stage,positive margin,major nerve involvement and interval from surgery to RT were associated with unfavorable oncological outcomes in malignant salivary gland tumors treated with surgery and postoperative intensity modulated radiotherapy(IMRT).Distant metastasis was the most frequent cause of treatment failure.Our results show that postoperative IMRT leads to excellent survival of patients with salivary gland tumors and is generally well tolerated.