br Clinical trial registration Name A Prospective Observatio
Clinical trial registration: Name: A Prospective, Observational, Real-world Study Based on the Register System of
Oral and Maxillofacial Malignant Tumors. (ClinicalTrials.gov ID: NCT02395367)
Many studies have shown that the depth of invasion (DOI) is an important independent prognostic factor for Moniliformin node metastasis and survival in patients with tongue cancer [1–7]. The eighth edition of the American Joint Committee on Cancer (AJCC) staging manual re-commends tumor invasion depths greater than 5 mm and 10 mm as the standard thresholds for T staging of oral cancer . The introduction of
DOI has improved the accuracy of oral cancer staging to a certain ex-tent. However, the eighth edition of AJCC staging requires greater ac-curacy in data measurement because millimeter-scale errors can lead to changes in staging and treatment options.
The depth of tumor invasion can be obtained by preoperative ima-ging examination and analysis of intraoperative and postoperative pa-thological sections. However, whether 5- and 10-mm thresholds for the DOI can be used as staging criteria for each time point warrants
Abbreviations: OS, overall survival; DSS, disease-specific survival; AJCC, American Joint Committee on Cancer; DOI, depth of invasion; MRI, magnetic resonance imaging; DMP, diﬀerence between MRI and postoperative pathological sections; DMI, diﬀerence between MRI and intraoperative pathological sections; DIP, dif-ference between intraoperative and postoperative pathological sections; TD-DMI, two-dimensional tumor margin diﬀerence between MRI and intraoperative pa-thological sections; TD-DMP, two-dimensional tumor margin diﬀerence between MRI and postoperative pathological sections; LoA, limit of agreement
Corresponding author at: Department of Beijing Stomatological Hospital, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing 100050, PR China.
1 Co-first authors. These authors equally contributed to this research.
exploration. False-positive results on clinical images (such as MRI) and atrophy of postoperative pathological sections have been reported [9–13]. Unfortunately, no definite conclusion has been established re-garding the specific value of measurement diﬀerences. Therefore, a prospective cohort study was designed to compare the consistency of DOI measured by preoperative MRI and by the analysis of in-traoperative and postoperative pathological sections based on 1-mm thin-layer MRI and digital analysis techniques. The prognostic in-filtration depth was also analyzed (ClinicalTrials.gov ID: NCT02395367).
Materials and methods
From April 2015 to December 2017, patients with squamous cell carcinoma of the tongue who were first diagnosed at Beijing Stomatological Hospital, Capital Medical University were included in the study. Sex and age were not restricted. Patients who were ineligible for MRI and those who had T4-stage disease or recurrent disease or who had received neoadjuvant chemotherapy or prior radiotherapy were excluded. Basic information including sex, age, tumor location, TNM stage (according to the seventh edition of AJCC), tumor morphology (invasive, exogenous, ulcerative, and necrotic), and pathological N stage was recorded. All patients underwent surgical treatment first, i.e., enlarged primary resection or enlarged en bloc resection, modified ra-dical neck dissection for patients with cervical metastases, and selective lymph node dissection (I-III) for T2-3N0 patients; T1N0 patients were monitored and followed up.
Imaging techniques and DOI measurements via MRI were performed in patients without contraindications for MRI on a 1.5-T MR unit (Magnetom Aera, Siemens Medical Solution, Shenzhen, China), and the section thickness was 1 mm. All patients underwent preoperative MRI scanning within one week of the date of surgery. The scanning protocol included T1 (repetition time [TR] 912 ms, echo time [TE] 17 ms) and T2 (TR 5000 ms, TE 99 ms) axial, coronal, and sagittal sequences along with T2 axial and coronal sequences with fat suppression (FS) (TR 5830 ms, TE 99 ms). After intravenous injection of contrast media, T1-weighted (TR 548 ms, TE 17 ms) axial, coronal, and sagittal sequences with FS were performed. After viewing the above DICOM data with syngo.via, coronal/axial images of the maximum depth of tumor in-vasion were obtained by comparing the layers in T2 sequences (Fig. 1a). During the operation, the tumor specimens were dissected along a coronal/axial interval of 3 mm, and the maximum DOI was measured