Lu Kuan, Zhou Chenxia, Ren Jiaming, Ni Jialu, Yang Weisen, Wang Yeqing, Jin Dan, Qian Jianjun, Zhu Yaqun, Shi Dai, Hu Wentao, Xu Liang
The Second Affiliated Hospital of Soochow University, Suzhou, China.
Suzhou Medical College, Soochow University, Suzhou, China.
Front Public Health. 2025 Jan 7;12:1526147. doi: 10.3389/fpubh.2024.1526147. eCollection 2024.
Hypothyroidism is a common sequela after radiotherapy for nasopharyngeal carcinoma (NPC). Magnetic resonance imaging (MRI) has gained prominence in thyroid imaging, leveraging its non-ionizing radiation, high spatial resolution, multiparameter and multidirectional imaging. Few previous studies have investigated the evaluation of radiation-induced thyroid injury by MRI.
MRI and radiotherapy data of 32 patients who were first diagnosed with nasopharyngeal carcinoma in our hospital from April 2015 to April 2024 and underwent radiotherapy in the radiotherapy department were retrospectively collected. Before, during and after radiotherapy, the thyroid morphology was observed on MR images, and the quantitative parameters of size (width, thickness) were measured on T1-weighted images. The signal intensity (SI) of the thyroid gland was measured on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI) and contrast-enhanced T1-weighted imaging. The differences in thyroid parameters at different time points before and after radiotherapy were compared. The correlation between the MRI quantitative parameters of the thyroid and the radiation dose volume of the thyroid and the radiation dose of the pituitary were analyzed.
The width, thickness and volume of the thyroid decreased gradually before, during and 6 and 12 months after radiotherapy. They were negatively correlated with the mean thyroid dose and V50 ( < 0.05), but were not significantly correlated with the maximum and minimum thyroid doses, V30 and V35 ( > 0.05). The T1WI relative signal intensity (RSI), T2WI RSI, and enhanced T1WI RSI of the thyroid gland gradually decreased from before radiotherapy to during radiotherapy and 6 months and 12 months after radiotherapy. The T1WI RSI, T2WI RSI, and enhanced T1WI RSI during radiotherapy and 6 months and 12 months after radiotherapy were negatively correlated with the mean radiation dose, V40, V45, and V50 of the thyroid gland ( < 0.05), but were not significantly correlated with the maximum radiation dose, minimum radiation dose, V30, and V35 of the thyroid gland or the radiation dose of the pituitary gland ( > 0.05).
Quantitative MRI analysis can non-invasively and effectively show the changes in thyroid shape, size and signal intensity in patients with nasopharyngeal carcinoma before and after radiotherapy, which is crucial for early and accurate assessment of thyroid damage, enabling timely treatment to preserve thyroid function.
甲状腺功能减退是鼻咽癌（NPC）放疗后的常见后遗症。磁共振成像（MRI）凭借其非电离辐射、高空间分辨率、多参数和多方向成像等优势，在甲状腺成像中发挥着重要作用。此前很少有研究探讨MRI对放射性甲状腺损伤的评估。
回顾性收集2015年4月至2024年4月在我院初诊为鼻咽癌并在放疗科接受放疗的32例患者的MRI和放疗数据。在放疗前、放疗期间及放疗后，观察MR图像上的甲状腺形态，并在T1加权图像上测量大小（宽度、厚度）的定量参数。在T1加权成像（T1WI）、T2加权成像（T2WI）和增强T1加权成像上测量甲状腺的信号强度（SI）。比较放疗前后不同时间点甲状腺参数的差异。分析甲状腺MRI定量参数与甲状腺辐射剂量体积及垂体辐射剂量之间的相关性。
放疗前、放疗期间以及放疗后6个月和12个月，甲状腺的宽度、厚度和体积逐渐减小。它们与甲状腺平均剂量和V50呈负相关（<0.05），但与甲状腺最大和最小剂量、V30和V35无显著相关性（>0.05）。甲状腺的T1WI相对信号强度（RSI）、T2WI RSI和增强T1WI RSI从放疗前到放疗期间以及放疗后6个月和12个月逐渐降低。放疗期间以及放疗后6个月和12个月的T1WI RSI、T2WI RSI和增强T1WI RSI与甲状腺平均辐射剂量、V40、V45和V50呈负相关（<0.05），但与甲状腺最大辐射剂量、最小辐射剂量、V30和V35或垂体辐射剂量无显著相关性（>0.05）。
MRI定量分析能够无创且有效地显示鼻咽癌患者放疗前后甲状腺形态、大小和信号强度的变化，这对于早期准确评估甲状腺损伤至关重要，有助于及时治疗以保护甲状腺功能。
