Evaluation of pretreatment computed tomography as a predictor of local control in T1/T2 pyriform sinus carcinoma treated with definitive radiotherapy.

Abstract

This study was undertaken to determine whether pretreatment computed tomography (CT) findings can predict local control in pyriform sinus carcinoma treated with definitive radiotherapy (RT). Twenty-three patients with pyriform sinus carcinoma (T1: n = 5; T2: n = 18) were treated with high-dose RT and followed for a minimum of 2 years. Tumor volumes and extent were determined on pretreatment CT studies. The specific CT parameters assessed were analyzed as predictors of local control. There was a significant decrease in local control rate for tumors over 6.5 mL (1 of 4 [25%]) relative to tumors under 6.5 mL (17 of 19 [89%]; p = .021). Sensitivity and specificity for local control using this cutoff were 94% and 60%, respectively. Tumor score, as a measure of anatomic extent, was also found to be a significant predictor of local control (p = .033). The local control rate was not influenced significantly by the presence of "minimal" apex disease (< 10 mm in greatest dimensions as measured on CT) but decreased significantly when "bulk" apex disease (> OR = 10 mm) was present (p = .027). Laryngeal cartilage sclerosis was not a significant predictor of outcome. Computed tomography can stratify pyriform sinus carcinomas into groups more or less likely to be locally controlled with definitive RT.