Early glottic squamous cell carcinoma. Predictive value of MR imaging for the rate of 5-year local control with radiation therapy.

PURPOSE: To evaluate MR findings in early (T1 and T2 stages) glottic carcinomas and the predictive value of MR imaging for the rate of 5-year local control with radiation therapy.

MATERIAL AND METHODS: Eighty-three patients with early glottic carcinomas were prospectively examined with MR at 1.5 T. MR investigation included unenhanced T1-weighted, T2-weighted, dynamic and contrast-enhanced T1-weighted images. Three patients with presumed advanced diseases on MR were initially treated with total laryngectomy and were excluded from the study. The remaining 80 patients were treated with radiation therapy with curative intent. Tumor detectability, size and relationship to the thyroid cartilage were determined on MR images. The MR findings were then correlated with the rate of local control.

RESULTS: Forty-eight of 80 lesions (60%) were detected on MR imaging. All detected lesions but 1 demonstrated increased signal on T2-weighted images. The lesions were best delineated on dynamic images (statistically significant). The 5-year local control rate with radiation therapy was 72%. Univariate analysis revealed clinical T stage, MR detectability, tumor size and relationship to the thyroid cartilage as significant predictors. Multivariate analysis revealed that the relationship to the thyroid cartilage was an independent factor.

CONCLUSION: MR provides prognostic information about the results of definitive radiation therapy. To evaluate the tumor extension in lesions detected on precontrast MR images, contrast-enhanced dynamic images should be obtained.