Reliability of Interpretation of CT Examination of the Larynx in Patients with Glottic Laryngeal Carcinoma

INTRODUCTION: Reports in literature suggest that tumor volume, cartilage invasion, and cartilage sclerosis are independent prognostic factors for tumor control in radiotherapy as primary treatment of laryngeal carcinomas. OBJECTIVE: Assessment of the interobserver variability and prognostic value in the measurement of tumor volume, cartilage invasion, and sclerosis. MATERIALS AND METHODS: Retrospective analysis of 55 CT scans by three independent observers. Volume measurements and determination of cartilage invasion, cartilage sclerosis, and tumor localization were calculated. Correlation between the prognostic factors and radiotherapy was calculated for each observer. RESULTS: Values for interobserver agreement varied substantially; cartilage invasion (κ value: −0.02 to 0.66), cartilage sclerosis (κ value: 0.13 to 0.57), tumor localization of subsites (κ value: 0.03 to 0.60), and tumor volume (correlation: 0.34 to 0.73). The found interobserver variation makes it impossible to establish accurate prognostic factors. CONCLUSION: Determination of tumor volume, cartilage invasion, and cartilage sclerosis on the basis of CT imaging shows considerable interobserver variation; clinical significance appears to be limited. EBM rating: B-3a