鼻咽癌放疗前后唾液腺影像结构与功能的变化及相关因素分析

Changes of the Structure and Function of Salivary Glands in Patients with Nasopharyngeal Carcinoma Before and After Radiotherapy and Its Related Factors

[目的]利用DW-MRI技术观察鼻咽癌放疗前后不同时间段唾液腺(双侧腮腺及颌下腺)体积和DW-MRI ADC值的变化规律,探讨DW-MRI在唾液腺放射性损伤评价方面的价值。[方法]选择30例鼻咽癌患者作为研究对象,在放疗前后不同时间段行DW-MRI检查,记录放疗前后不同时间段唾液腺(双侧腮腺及颌下腺)体积和DW-MRI ADC值的测量值,分析两者的变化规律及其与唾液腺照射剂量的相关关系。[结果]30例鼻咽癌患者放疗期间腮腺和颌下腺的ADC值均明显升高,于放疗结束后3个月达最高值,此后呈缓慢下降趋势;各个时段酸刺激后唾液腺的ADC值呈不同程度升高。放疗期间及放疗后腮腺及颌下腺的体积呈逐渐下降的趋势,以放射治疗开始至放疗第4周最为显著,放疗结束时腮腺体积缩小36.0%±6.3%,颌下腺缩小29.3%±4.1%。放疗后3个月与放疗前的唾液腺体积变化率(ΔV)和唾液腺DW-MRI ADC值变化(ΔADC)与腮腺和颌下腺的平均剂量(Dmean)呈正相关。[结论 ]DW-MRI在唾液腺放射性损伤评价方面具有一定程度的实用价值,ΔV和ΔADC可作为唾液腺损伤的评价指标,但研究结果还需通过扩大样本量进一步验证。

[Purpose] To observe the changes of the volume and DW-MRI ADC value of salivary glands（bilateral parotid and submandibular gland） at different time periods in patients with nasopharyngeal carcinoma before and after radiotherapy,and further to explore the value of DWMRI in salivary gland radioactive damage evaluation. [Methods] A total of 30 patients with nasopharyngeal carcinoma were recruited. Patients were treated with IMRT. DW-MRI scanning was done at different time periods before and after radiotherapy for each patient,and then the volume and ADC value of salivary glands were recorded. The correlation of radiation doses and the volume and ADC value of salivary glands were analyzed. [Results] The DW-MRI ADC value of bilateral parotid and submandibular gland significantly increased after radiation,up to a maximum value at3 months after the end of radiotherapy,then decreased slowly. The DW-MRI ADC value of the salivary glands increased at different degree after acid stimulation at each period. The volume of bilateral parotid and submandibular gland was gradually declining after radiation,the most significant decline happened at first 4 weeks during radiotherapy. At the end of radiotherapy,the mean volume of parotid gland and submandibular gland reduced（36.0 ±6.3）% and（29.3±4.1）%. The change rate of volume（ΔV） and ADC value（ΔADC） of parotid and submandibular gland between before radiotherapy and 3 months after the end of radiotherapy were positively correlated to the mean radiation dose（Dmean） of each gland. [Conclusion] DW-MRI has a good clinical value in salivary gland radioactive damage evaluation. ΔVand ΔADCcan be as index to evaluate salivary gland radioactive damage,but need to further verify by expanding samples.