鼻咽癌IMRT前后唾液腺功能变化及与受照剂量的关系

目的:探讨鼻咽癌患者调强放射治疗（IMRT）前后唾液腺的功能变化及与受照剂量的关系。方法:选取广西医科大学第一附属医院接受IMRT初治鼻咽癌患者30例为研究对象，在放疗前、放疗后3个月采用99mTcO4-SPECT唾液腺动态显像测定腮腺、颌下腺的时间-放射性曲线（TAC）、最大浓聚率（MAR）和酸刺激最大分泌率（MSR），研究唾液腺的功能变化及与受照剂量的关系。结果:放疗后3个月出现1~2级口干症状，腮腺、颌下腺TAC曲线主要表现为轻中度受损，口干程度、TAC曲线与唾液腺受照剂量正相关。放疗后3个月较放疗前腮腺MAR、MSR和颌下腺MSR明显减低（P<0.05），而颌下腺的MAR无减低（P>0.05），但两组唾液腺的MAR、MSR对比差异无统计学意义（P>0.05），两组唾液腺照射剂量均合理。结论:鼻咽癌患者IMRT后出现唾液腺摄取和排泄功能轻中度受损，引起1~2级口干，IMRT能够将唾液腺的受照射剂量控制在合理范围内。

Changes in salivary gland function before and after intensity-modulated radiotherapy for nasopharyngeal carcinoma and the relationship with irradiation doses

Abstract: Objective To investigate the changes of salivary gland function in patients with nasopharyngeal carcinoma (NPC) before and after intensity-modulated radiotherapy (IMRT) and discuss the relationship between the changes and irradiation doses. Methods Thirty NPC patients who underwent IMRT in the First Affiliated Hospital of Guangxi Medical University were examined with 99mTcO4-SPECT salivary gland dynamic imaging before and at 3 months after radiotherapy to determine the time-activity curve (TAC), maximum accumulation ratio (MAR) and acid-stimulated maximum secretion rate (MSR) of the parotid glands and the submandibular glands for studying the relationship between changes in salivary gland function and irradiation dose. Results The symptom of grade 1-2 dry mouth occurred at 3 months after radiotherapy. TAC showed that there were mainly mild to moderately damages to the parotid glands and the submandibular glands. The degree of dry mouth and TAC were positively correlated with the irradiation doses to the salivary glands. The MAR and MSR of the parotid gland and the MSR of the submandibular gland were significantly lower at 3 months after radiotherapy than those before radiotherapy (P<0.05), but the MAR of the submandibular gland was not reduced (P>0.05). There was no statistically significant difference in the MAR and MSR between affected salivary gland and contralateral salivary gland (P>0.05). The irradiation doses to the bilateral salivary glands were reasonable. Conclusion There are mild to moderate damages to the uptake and excretion functions of the salivary glands in NPC patients, which can cause grade 1-2 dry mouth. In IMRT for NPC, the doses to the salivary glands can be controlled in a reasonable range.