PURPOSE: 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. METHODS AND MATERIALS: 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. RESULTS: 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. CONCLUSION: 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.
PURPOSE: Besides sparing the parotid gland, sparing the submandibular gland is considered to be important in preventing xerostomia in head-and-neck cancerpatients. 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. METHODS AND MATERIALS: Sixteen oropharyngeal cancerpatients 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. RESULTS: 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. CONCLUSION: 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.
Authors: Mischa de Ridder; Cornelis P J Raaijmakers; Frank A Pameijer; Remco de Bree; Floris C J Reinders; Patricia A H Doornaert; Chris H J Terhaard; Marielle E P Philippens Journal: Cancers (Basel) Date: 2022-06-20 Impact factor: 6.575