The role of Magnetic resonance sialography in evaluating radiation-induced xerostomia for patients with early stage nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the value of magnetic resonance sialography (MRS) as a noninvasive tool in evaluating major salivary gland function before and after radiotherapy (RT) for nasopharyngeal carcinoma patients.Methods From August 2009 to June 2010,patients with stage Ⅰ and Ⅱa (AJCC/UICC 2002) nasopharyngeal carcinoma were enrolled.All the patients were treated with intensity modulated radiation therapy alone.MRS with salivary stimulation was performed in patients before and after RT on a 3.0T MR scanner.An MRS categorical scoring system was used to compare the visibility of ducts pre-RT and post-RT.The relationship between MRS score and EORTC Core QOL and EORTC Head and Neck QOL was analyzed.Spearman rank correlation test was performed to analyze the non-stimulated and stimulated MRS findings and the clinical severity of xerostomia.Results All 10 enrolled patients completed planned treatment.The mean dose of the parotid glands and submandibular glands were (37.99 + 3.70) Gy and (55.65 + 2.99) Gy,respectively.Good-quality MRS images were obtained.The visibility scores of both the parotid and submandibular ducts were increased after secretion stimulation.Irradiation decreased the visualization of the salivary ducts and attenuated the response to secretion stimulation.There were specific correlations between post-RT secretion response of the parotid gland and EORTC QLQ scales ( global QOL scale in QLQ-C30 ( rs =0.636,P =0.048 ) and xerostomia scale in QLQ H&N35 ( rs =- 0.694,P =0.026) ).Conclusions MRS can be used as a non-invasive way to evaluated of the functional changes of major salivary glands before and after RT and as a promising approach for investigating radiation-induced xerostomia.