Preoperative Prediction of the Aggressiveness of Oral Tongue Squamous Cell Carcinoma with Quantitative Parameters from Dual-Energy Computed Tomography

Abstract

Objectives: To determine whether quantitative parameters derived from dual-energy computed tomography (DECT) were predictive of the aggressiveness of oral tongue squamous cell carcinoma (OTSCC) including the pathologic stages, histologic differentiation, lymph node status, and perineural invasion (PNI).

Methods: Between August 2019 and March 2021, 93 patients (mean age, 54.6 ± 13.8 years; 66 men) with pathologically diagnosed OTSCC were enrolled in this prospective study. Preoperative DECT was performed and quantitative parameters (e.g., slope of the spectral Hounsfield unit curve [λ_Hu], normalized iodine concentration [nIC], normalized effective atomic number [nZ_eff], and normalized electron density [nRho]) were measured on arterial phase (AP) and venous phase (VP) DECT imaging. Quantitative parameters from DECT were compared between patients with different pathologic stages, histologic differentiation, lymph node statuses, and perineural invasion statuses. Logistic regression analysis was utilized to assess independent parameters and the diagnostic performance was analyzed by the receiver operating characteristic curves (ROC).

Results: λ_Hu and nIC in AP and λ_Hu, nZ_eff, and nIC in VP were significantly lower in stage III-IV lesions than in stage I-II lesions (p < 0.001 to 0.024). λ_Hu in VP was an independent predictor of tumor stage with an odds ratio (OR) of 0.29, and area under the curve (AUC) of 0.80. λ_Hu and nIC were higher in well-differentiated lesions than in poorly differentiated lesions (p < 0.001 to 0.021). The nIC in VP was an independent predictor of histologic differentiation with OR of 0.31, and AUC of 0.78. λ_Hu and nIC in VP were lower in OTSCCs with lymph node metastasis than those without metastasis (p < 0.001 to 0.005). λ_Hu in VP was the independent predictor of lymph node status with OR of 0.42, and AUC of 0.74. No significant difference was found between OTSCCs without PNI and those with PNI in terms of the quantitative DECT parameters.

Conclusion: DECT can be a complementary means for the preoperative prediction of the aggressiveness of OTSCC.

Keywords: Aggressiveness; Dual-energy CT; Oral tongue squamous cell carcinoma; histologic differentiation; lymph node status; pathologic stages.

Figure 1

Flowchart shows the strategy for OTSCC analysis and data processing in this study.

Figure 2

The receiver operating characteristic curves of quantitative DECT parameters for discriminating the different aggressiveness of OTSCC. (A) The receiver operating characteristic curves of λ_Hu in VP for discriminating stage III-IV lesions from stage I-II lesions. (B) The receiver operating characteristic curves of nIC in VP for discriminating well-differentiated lesions (moderately or highly differentiated) from poorly differentiated lesions. (C) The receiver operating characteristic curves of λ_Hu in VP for discriminating lesions without lymph node metastasis from those with lymph node metastasis.

Figure 3

CT images in a 50-year-old man with well-differentiated T2N0M0 OTSCC in stage II. (A–D) Arterial phase imaging of the primary tumor (arrow). (A) Contrast-enhanced 40-keV monochromatic image shows lesion with mean CT value of 255.26 HU. (B) Effective atomic number map shows lesion with mean Z_eff value of 8.70. (C) Iodine-based pseudo-colorized image shows lesion with mean IC of 3.16 mg/ml. (D) Spectral Hounsfield unit curve shows lesion with mean λ_Hu of 3.21 HU/keV. (E–H) Venous phase imaging of the primary tumor (arrow). (E) Contrast-enhanced 40-keV monochromatic image shows lesion with mean CT value of 325.53 HU. (F) Effective atomic number map shows lesion with mean Z_eff value of 9.17. (G) Iodine-based pseudo-colorized image shows lesion with mean IC of 3.50 mg/ml. (H) Spectral Hounsfield unit curve shows lesion with mean λ_Hu of 4.23 HU/keV.

Figure 4

CT Images in a 65-year-old man with poorly differentiated T3N1M0 OTSCC in stage III. (A–D) Arterial phase imaging of the primary tumor (arrow). (A) Contrast-enhanced 40-keV monochromatic image shows lesion with mean CT value of 167.12 HU. (B) Effective atomic number map shows lesion with mean Z_eff value of 8.37. (C) Iodine-based pseudo-colorized image shows lesion with mean IC of 1.53 mg/ml. (D) Spectral Hounsfield unit curve shows lesion with mean λ_Hu of 1.95 HU/keV. (E–H) Venous phase imaging of the primary tumor (arrow). (E) Contrast-enhanced 40-keV monochromatic image shows lesion with mean CT value of 212.34 HU. (F) Effective atomic number map shows lesion with mean Z_eff value of 8.72. (G) Iodine-based pseudo-colorized image shows lesion with mean IC of 2.2 mg/ml. (H) Spectral Hounsfield unit curve shows lesion with mean λ_Hu of 2.55 HU/keV.