Value of Computed Tomography-Based Tumor Volume as a Predictor of Outcomes in Hypopharyngeal Cancer After Treatment With Definitive Radiotherapy

Objectives: To investigate the value of pretreatment computed tomography (CT) volumetric analysis for the prediction of treatment outcome in patients with hypopharyngeal cancer (HPC) treated by definitive radiotherapy (RT). Methods: From January 2000 through February 2004, 63 patients with HPC were enrolled for a retrospective analysis. The pyriform sinus was the principle site of involvement in 62 cases. All patients received with 1.8 Gy daily to a total dose of 68.4 to 73.8 Gy (median, 70.2 Gy). Contrast‐enhanced CT images were transferred to a planning system. Tumor volume measurement was derived from summation of the primary and metastatic nodal tumor. Results: With a median follow‐up of 38 (range, 24–68) months, the 5 year local relapse‐free survival (LRFS) was 83% for patients with T1 to T2 disease, 46% for those with T3 disease, and 40% for those with T4 disease (P = .01). The 5 year LRFS was 75% for those with tumors less than 40 mL and 26% when volumes were 40 mL of larger (P = .0001). For patients with T3 to T4 disease, the 5 year LRFS was 70% for those with tumors less than 40 mL and 24% when volumes were 40 mL or larger (P = .0005). Multivariate analyses of local relapse‐free survival revealed two prognostic factors: tumor volume more than 40 mL and the involvement of the larynx. Conclusions: CT‐based tumor volumes are a strong predictor of outcomes for HPC treated using definitive RT. A selected group of patients, mainly those with tumor volumes less than 40 mL, should be considered for laryngeal preservation.