BACKGROUND Xerostomia caused by radiation-induced salivary glands injury has a considerable impact on patients' quality of life. Nowadays, the existed different methods of evaluating xerostomia in clinical practice there are still some disadvantages and limitations. This study used diffusion-weighted magnetic resonance imaging (DW-MRI) with gustatory stimulation to assess salivary glands function after intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC). METHODS DW-MRI was performed in 30 NPC patients and swab method was used to calculate rest and stimulated salivary flow rates (SFR). DW sequence at rest and then repeated ten times during stimulation were obtained. Apparent diffusion coefficients (ADCs) maps of three glands were calculated. Patients before and after RT were recorded as xerostomia and non-xerostomia groups separately. Rest and stimulated ADCs, ADCs increase rates (IRs), time to maximum ADCs (Tmax), ADCs change rates (CRs), rest and stimulated SFR, SFR increase rates (IRs) and SFR change rates (CRs) before and after RT were assessed. RESULTS The rest and stimulated ADCs of three glands after RT were higher than those before RT (p < 0.001). The rest and stimulated SFR of all salivary glands after RT were lower than those before RT (p < 0.001). A correlation existed between rest ADCs of submandibular glands and rest SFR of submandibular mixed with sublingual glands and full three glands before RT (p = 0.019, p = 0.009), stimulated ADCs and stimulated SFR in parotid glands before RT (p = 0.047). The rest ADCs of parotid glands after RT correlated to XQ scores (p = 0.037). CONCLUSIONS The salivary glands' ADCs increased after RT both in rest and stimulated state due to the radiation injury and the ADCs correlated with SFR and XQ scores of evaluating the xerostomia in clinical practice.

中文翻译：

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通过动态扩散加权MR成像和味觉刺激评估强度调节放疗前后鼻咽癌的唾液腺功能。

背景技术由辐射引起的唾液腺损伤引起的口干症对患者的生活质量具有相当大的影响。如今，在临床实践中存在不同的评价口干症的方法，仍然存在一些缺点和局限性。这项研究在鼻咽癌（NPC）患者中使用了带有味觉刺激的弥散加权磁共振成像（DW-MRI）评估了调强放疗（IMRT）后唾液腺的功能。方法对30例NPC患者进行DW-MRI检查，并采用拭子法计算静息和唾液流速（SFR）。获得静止时的DW序列，然后在刺激期间重复十次。计算了三个腺体的表观扩散系数（ADC）图。RT之前和之后的患者分别记录为口干症和非口干症组。静止和刺激ADC，ADC增加速率（IR），达到最大ADC的时间（Tmax），ADC变化速率（CR），静止和刺激SFR，RT前后的SFR增加速率（IR）和SFR变化速率（CR）评估。结果放疗后三个腺体的其余ADC和受激ADC均高于放疗前（p <0.001）。放疗后所有唾液腺的其余部分和受激SFR均低于放疗前（p <0.001）。RT之前，颌下腺的其余ADC与颌下腺混合舌下腺和完整的三个腺的其余SFR之间存在相关性（p = 0.019，p = 0.009），RT前腮腺的刺激ADC和SFR刺激之间（p = 0.047）。RT后其余的腮腺ADC与XQ评分相关（p = 0.037）。结论放疗后，由于辐射损伤，唾液腺的ADC在静止和刺激状态下均增加，并且ADC与临床实践中评估口干症的SFR和XQ得分相关。