Quantitative Diffusion-Weighted MRI Parameters and Human Papillomavirus Status in Oropharyngeal Squamous Cell Carcinoma

Abstract

BACKGROUND AND PURPOSE:Patients with human papillomavirus-positive oropharyngeal squamous cell carcinomas have a better survival rate than those with human papillomavirus-negative oropharyngeal squamous cell carcinomas. DWI characterizes biologically relevant tumor features, and the generated ADC may also provide prognostic information. We explored whether human papillomavirus status and ADC values are independent tumor characteristics.

Apparent Diffusion Coefficient Histograms of Human Papillomavirus–Positive and Human Papillomavirus–Negative Head and Neck Squamous Cell Carcinoma: Assessment of Tumor Heterogeneity and Comparison with Histopathology

“…In agreement with Nakahira et al 12 and Driessen et al, 22 we found that mean ADCs were significantly lower in HPVϩ than in HPVϪ cancers. However, our data are in contradiction to results reported by Schouten et al, 14 who did not find a statistically significant difference between ADCs of both tumor types.…”

“…Recent publications have attempted to determine whether mean ADC values calculated by monoexponential fitting could be used to determine the HPV status in HNSCC. 12,14,22 In contrast to the intravoxel incoherent motion biexponential model, the monoexponential model does not differentiate between molecular movement caused by microperfusion and true diffusion caused by Brownian movement. 23 To obtain a robust fitting, biexponential models require the acquisition of 6 -12 b-values, leading to increased examination time and a higher percentage of motion artifacts.…”

“…Publications evaluating the association between mean ADC values with monoexponential fitting and the HPV status in HNSCC have yielded contradictory results; although some authors suggested that mean ADCs at 1.5T are lower in HPVϩ than in HPVϪ HNSCCs, others found no significant differences. 12,14,22 In these studies, the methodology of ROI contouring, the type of DWI sequence used, and the range and num- ber of b-values vary. Nakahira et al 12 contoured the largest axial cross-sectional tumor area on a single section without excluding necrotic portions, Driessen et al 22 contoured the entire tumor volume excluding necrotic portions, and Schouten et al 14 contoured the largest cross-sectional area on a single section excluding necrotic portions.…”

“…12,14,22 In these studies, the methodology of ROI contouring, the type of DWI sequence used, and the range and num- ber of b-values vary. Nakahira et al 12 contoured the largest axial cross-sectional tumor area on a single section without excluding necrotic portions, Driessen et al 22 contoured the entire tumor volume excluding necrotic portions, and Schouten et al 14 contoured the largest cross-sectional area on a single section excluding necrotic portions. In agreement with Nakahira et al 12 and Driessen et al, 22 we found that mean ADCs were significantly lower in HPVϩ than in HPVϪ cancers.…”

“…[9][10][11][12] These reported ADC values are based on a monoexponential fitting model with 2 b-values (b ϭ 0 and b ϭ 800 -1000 s/mm 2 ). [9][10][11]13 Mean ADC values are often calculated based on a single freehand ROI drawn over the largest axial tumor area, 14 or alternatively, they are based on elliptical…”