Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands.
Radiother Oncol. 2010 Nov;97(2):239-43. doi: 10.1016/j.radonc.2010.08.014. Epub 2010 Sep 16.
Besides sparing the parotid gland, sparing the submandibular gland is considered to be important in preventing xerostomia in head-and-neck cancer patients. Delineation of the submandibular gland at CT, and even on T(1)- and T(2)-weighted MR images, is difficult, due to low contrast with the surrounding tissues. MR sialography might be used for delineation.
Sixteen oropharyngeal cancer patients received a CT and MRI exam as part of the standard treatment imaging protocol. Patients were scanned in their five-point RT immobilization mask. The MRI exam included T(1)- and T(2)-weighted MRI scans and an MR sialography scan. Thirty submandibular glands were delineated on only CT, on the combined CT and T(1)- and T(2)-weighted MRI scans and on all MR images. A Wilcoxon signed-rank test was performed to test if the delineated volumes were significantly different.
The delineated volume of the submandibular gland was 7.3mL in the CT-delineation, 7.1mL in the CT/MRI-delineation and 8.1mL in the MRI-delineation. The MRI-delineation was significantly larger than the other delineations (p<0.001). The differences were mainly located in the cranial direction.
The delineation of the submandibular gland was improved in the cranial direction by using T(1)- and T(2)-weighted MRI and MR sialography, compared to the other delineations.
除了保护腮腺外，保护颌下腺被认为对预防头颈部癌症患者的口干症很重要。由于与周围组织对比度低，在 CT 上，甚至在 T1 和 T2 加权磁共振图像上，颌下腺的勾画都很困难。磁共振唾液腺造影术可能用于勾画。
16 例口咽癌患者接受了 CT 和 MRI 检查，作为标准治疗成像方案的一部分。患者在五点 RT 固定面罩中进行扫描。MRI 检查包括 T1 和 T2 加权 MRI 扫描以及磁共振唾液腺造影扫描。仅在 CT 上、在 CT 和 T1 和 T2 加权 MRI 扫描的组合上以及在所有 MRI 图像上勾画了 30 个颌下腺。采用 Wilcoxon 符号秩检验来检验勾画的体积是否存在显著差异。
在 CT 勾画中，颌下腺的勾画体积为 7.3mL，在 CT/MRI 勾画中为 7.1mL，在 MRI 勾画中为 8.1mL。MRI 勾画明显大于其他勾画（p<0.001）。差异主要位于颅侧。
与其他勾画相比，使用 T1 和 T2 加权 MRI 和磁共振唾液腺造影术在颅侧方向上改善了颌下腺的勾画。
