@phdthesis{oai:niigata-u.repo.nii.ac.jp:02000381,
 author = {Takamura, Masaki and 髙村, 真貴},
 month = {2022-04-15, 2022-04-15},
 note = {Objectives In 2017, depth (Depth of invasion: DOI) was introduced in the TNM classification of the 8th edition of the Union of International Cancer Control (UICC) and the 8th edition of the American Joint Committee on Cancer (AJCC). Histopathologically, DOI is defined as the vertical distance from the virtual plane connecting the basement membrane of the normal mucosa adjacent to the tumor to the deepest part of the tumor; however, there is no diagnostic imaging method for measuring DOI (image DOI). This study aimed to clarify the accuracy of intraoral ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) in preoperative image DOI measurement of T1/T2 tongue cancer through comparison with histopathological measurements. Methods Imaging of the primary lesions was performed by US, CT, and MRI at Niigata University Medical and Dental Hospital, and the lesions were classed into T1 and T2 based on the 8th edition of the AJCC/UICC, and surgery performed. There was histopathological confirmation of lesions as squamous cell carcinoma in 48 patients with tongue cancer. Cases classified as T3 and T4, cases in which preoperative chemotherapy and radiation therapy were performed, and cases where biopsy was performed before imaging were excluded. For preoperative image DOI measurements, the distance from the virtual line connecting the basal portion of the normal mucosa to the deepest portion of the tumor was determined by US. With CT and MRI, the measurement was from the virtual straight or curved line connecting the boundary between the tumor and the normal mucosa to the deepest part of the tumor. The measurement was performed using the axial image and coronal image after imaging for CT and using the axial image and coronal image by fat-suppressed T1-weighted and fat-suppressed T2-weighted imaging for MRI. For US, scanning was performed at a cross section close to the axial section, and the tumor depicted in the low echo was measured on a still image in the cross section that is depicted as the thickest. The image DOI in US, CT, and MRI and the histopathological DOI as base were comparatively investigated and statistical analyses were performed by Bland-Altman analysis and Spearman's rank correlation coefficient. Results Histopathologically, the minimum and maximum DOI were 0 mm and 10 mm, respectively, with a mean of 3.3 mm. Bland-Altman analysis showed that the US image DOI was overestimated by an average of 0.2 mm compared to the histopathological DOI, while CT and MRI image DOI were overestimated by an average of 2-3 mm. The comparison of CT and MRI revealed that the difference between the MRI and histopathological DOI, as well as the 95% limit of agreement, were smaller than those of the CT image DOI. The comparison of the T1-weighted and T2-weighted images after MRI imaging revealed that the lesions were overestimated with the T2-enhanced images. Spearman's rank correlation coefficient was greater in the order of US, MRI, and CT. Conclusions With regard to DOI measurement by preoperative diagnostic imaging of T1 and T2 squamous cell carcinoma, based on the findings from the comparison with the histopathological DOI, US is the most accurate measurement method. With CT and MRI, there tends to be overestimation of about 2 to 3 mm and so caution is required., Oral Radiology. 2021., 新大院博(歯)第493号},
 school = {新潟大学, Niigata University},
 title = {A comparative study between CT, MRI, and intraoral US for the evaluation of the depth of invasion in early stage (T1/T2) tongue squamous cell carcinoma},
 year = {}
}