Preradiotherapy Tumor Volume in Local Control of Squamous Cell Carcinoma of the Supraglottic Larynx

Objectives: Examine the utility of pretreatment computed tomography in predicting local control (LC) in squamous cell carcinoma of the supraglottic larynx treated with primary radiotherapy (RT). Methods: In total, 167 patients treated between 1983 and 2013 were reviewed. Patients had received pretreatment diagnostic computed tomographic imaging of the larynx and neck from which primary tumor volume (PrTV) was delineated. LC, larynx function at last follow-up, and RT complications were recorded. PrTV was evaluated with respect to outcome. Results: In this study, median age was 61 years, and mean follow-up was 96 months. In total, 43% had T1-T2, 46% had T3, and 11% had T4 disease; 49% had N0 disease. Median tumor volume, 5.1 cm(3) (0.4 to 188 cm(3)). Mean dose, 74 Gy; 20% received concurrent chemotherapy. Overall, 10-year LC was 78.9%. Ten-year LC stratified by tumor volume was: 0 to 4.9 cm3, 90.8%; 5 to 8.9 cm3, 67.3%; and > 9 cm(3), 69.4%. Ten-year LC with preserved larynx function was: 0 to 4.9 cm(3), 76.7%; 5 to 8.9 cm(3), 61.5%; and > 9 cm(3), 53.4%. LC and LC with preserved larynx function was significantly different between PrTV groups (P< 0.001). On multivariate analysis, PrTV was a significant predictor of LC and LC with preserved larynx function (P< 0.005). Six patients developed soft tissue necrosis; 2 suffered fatal carotid blowouts. Patients with grade 5 complications received concomitant chemotherapy. Four patients required total laryngectomy; 14 required permanent tracheostomy or gastrostomy tube. Conclusion: Pretreatment PrTV helps identify patients most likely to experience LC with primary RT alone or combined chemoradiation. LC for supraglottic larynx squamous cell carcinoma is optimal if the PrTV is < 5.0 cm(3).