Effectiveness of ultrasonography and computed tomography in assessing thyroid cartilage invasion in laryngeal and hypopharyngeal cancers.

OBJECTIVE

To evaluate the adequacy of ultrasonography (US) and computed tomography (CT) in the assessment of thyroid cartilage invasion in patients with airway cancer.

MATERIALS AND METHODS

Sixty-two consecutive patients referred to our institute underwent US and CT to stage laryngeal ( = 27) or hypopharyngeal ( = 35) cancer in this prospective study. Two radiologists, who were blinded to the patients' clinical histories and histopathology, evaluated thyroid cartilage invasion on US and CT separately and independently. Fifty-eight of the 64 patients (90%) underwent surgery. The histopathologic findings were used as the standard of reference for comparison and statistical analysis.

RESULTS

For thyroid cartilage invasion, the detection rate on CT and US was 98%. CT achieved a sensitivity of 91% and a specificity of 75%, while US attained a sensitivity of 98% and a specificity of 75%. The difference between CT and US in terms of sensitivity was not statistically significant.

CONCLUSION

US and CT have high diagnostic performance in evaluating thyroid cartilage invasion. US is more sensitive than CT in diagnosing invasion of the thyroid cartilage; however, the difference is not statistically significant. US can be used to solve the diagnostic dilemma of the presence or absence of cartilage invasion when CT is inconclusive, as CT is more widely used in staging laryngeal and hypopharyngeal cancers.