Clinical implication of computed tomography findings in patients with locally advanced squamous cell carcinoma of the larynx and hypopharynx.

Accurate tumor staging including involvement of laryngeal cartilage is important to treatment planning. Clinicians rely on imaging findings and determine initial laryngectomy for T4-stage cancer with functionless larynx or extralaryngeal spread (ELS). We examined the accuracy and prognostic value of preoperative CT findings for tumor staging in patients with locally advanced laryngeal and hypopharyngeal cancer. Ninety-four consecutive patients with clinically T3-T4-stage squamous cell carcinoma of the larynx or hypopharynx who underwent curative resection of primary tumor were reviewed. Preoperative CT findings were interpreted by a radiologist without pathologic information. Pathologic findings were used as the gold standard for correlating radiographic findings. CT imaging identified 23 (72%) of 32 cases of pathologically documented thyroid cartilage penetration and 24 (73%) of 33 cases of pathologically documented ELS. The positive predictive values for thyroid cartilage penetration and ELS were 70 and 80%, respectively. Pretreatment CT imaging up-staged 6 of 46 pT3 cases and all of 8 pT2 cases, while it down-staged 7 of 40 pT4 cases. The accuracy for clinical staging by CT imaging was 78%. Subglottic extension of the CT image was an independent variable for predicting thyroid cartilage penetration and ELS (P = 0.014). Thyroid cartilage penetration with or without ELS on CT scans is significantly associated with unfavorable DFS outcome of patients (P = 0.020). CT imaging is suboptimal in diagnosing TCP or ELS of advanced laryngeal cancer, but may be useful to predict patient survival by identifying clinically TCP.