Astreinidou Eleftheria, Roesink Judith M, Raaijmakers Cornelis P J, Bartels Lambertus W, Witkamp Theo D, Lagendijk Jan J W, Terhaard Chris H J
Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands.
Int J Radiat Oncol Biol Phys. 2007 Aug 1;68(5):1310-9. doi: 10.1016/j.ijrobp.2007.01.062. Epub 2007 May 7.
To evaluate whether magnetic-resonance (MR) sialography can be used to investigate radiation-induced xerostomia. Preradiotherapy (pre-RT) and postradiotherapy (post-RT) MR sialographic images of the major salivary ducts (parotid and submandibular) were compared.
Magnetic-resonance sialography was performed pre-RT, and 6 weeks and 6 months post-RT on 9 patients with T1-4N0-2M0 naso- or oropharyngeal tumors, on a 1.5-T MR scanner. Patients were positioned in the scanner, using a radiotherapy immobilization mask. Image registration of the MR sialograms pre- and post-RT with each other and with the CT and consequently the dose distribution was performed. A categorical scoring system was used to compare the visibility of ducts pre-RT and post-RT.
Good-quality MR sialographic images were obtained, and image registration was successful in all cases. The visibility score of the parotid ducts and submandibular ducts was reduced at 6 weeks post-RT, which means that the full trajectory of the salivary ducts, from the intraglandular space to the mouth cavity, was only partially visualized. For some of the parotid ducts, the visibility score improved at 6 months post-RT, but not for the submandibular ducts. The mean dose for the parotid glands was 35 Gy (1 standard deviation [SD] 3 Gy), and for the submandibular glands it was 62 Gy (SD, 8 Gy).
Three-dimensional MR sialography is a promising approach for investigating xerostomia, because radiation-induced changes to the saliva content of the ducts can be visualized.
评估磁共振（MR）涎管造影术是否可用于研究放射性口干症。比较主要涎腺导管（腮腺和颌下腺）放疗前（RT前）和放疗后（RT后）的MR涎管造影图像。
对9例T1-4N0-2M0鼻咽癌或口咽癌患者，在1.5-T MR扫描仪上于RT前、RT后6周和6个月进行磁共振涎管造影。患者使用放疗固定面罩置于扫描仪中。对RT前后的MR涎管造影图像以及CT图像进行图像配准，并由此获得剂量分布。采用分类评分系统比较RT前后导管的可视性。
获得了高质量的MR涎管造影图像，所有病例的图像配准均成功。RT后6周，腮腺导管和颌下腺导管可视性评分降低，这意味着涎腺导管从腺内间隙到口腔的完整走行仅部分可见。部分腮腺导管在RT后6个月可视性评分有所改善，但颌下腺导管未见改善。腮腺平均剂量为35 Gy（标准差[SD] 3 Gy），颌下腺为62 Gy（SD，8 Gy）。
三维MR涎管造影术是研究口干症的一种有前景的方法，因为可以可视化导管内唾液含量的放射性改变。
