Published in:
01-06-2013 | Head and Neck
Dynamic contrast-enhanced magnetic resonance imaging for characterising nasopharyngeal carcinoma: comparison of semiquantitative and quantitative parameters and correlation with tumour stage
Published in: European Radiology | Issue 6/2013
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Objectives
To evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for characterising nasopharyngeal carcinoma (NPC).
Methods
Forty-five newly diagnosed NPC patients were recruited. The initial enhancement rate (E
R
), contrast transfer rate (k
ep
), elimination rate (k
el
), maximal enhancement (MaxEn) and initial area under the curve (iAUC) were calculated from semiquantitative analysis. The K
trans
(volume transfer constant), v
e
(volume fraction) and k
ep
were calculated from quantitative analysis. Student’s t-test was used to evaluate the differences among tumour stages. Pearson’s correlation between the two sets of k
ep
was performed.
Results
Comparing tumours of T1/2 stage (n = 18) and T3/4 stage (n = 27), MaxEn (P = 0.030) and iAUC (P = 0.039) were both significantly different; however, the iAUC was the only independent variable with 69.6 % sensitivity and 76.5 % specificity respectively; v
e
was also significantly different (P = 0.010) with 69.6 % sensitivity and 70.6 % specificity respectively. No significant difference was found among N stages. The two sets of k
ep
s were highly correlated (r = 0.809, P < 0.001). Forty-three patients had chemoradiation, one palliative chemotherapy and one radiotherapy only. In the four patients with poor outcome, k
el,
E
R,
MaxEn and iAUC tended to be higher.
Conclusions
Neovasculature in higher T stage NPC exhibits some parameters of increased permeability and perfusion. Thus, DCE-MRI may be helpful as an adjunctive technique in evaluating NPC.
Key Points
• The correct assessment of nasopharyngeal carcinoma (NPC) is important for planning treatment.
• Neovasculature in higher T stage NPC exhibits increased permeability and perfusion.
• Correlation between quantitative and semi-quantitative analysis validates the robustness of DCE-MRI.
• DCE-MRI may be helpful as an adjunctive parameter in evaluating NPC.