Correlation of tumor volume with local control in laryngeal carcinoma treated by radiotherapy

An analysis of 37 patients with laryngeal carcinoma (T2 or greater) treated with radical radiotherapy, with surgery reserved for failure, was performed to determine if tumor volume, alone or in association with other prognostic factors, accurately predicted the probability of local control. Patient records were reviewed retrospectively and the following data extracted: age, sex, laryngeal region and number of sites involved by tumor, T and N categories, and success or failure of radiotherapy. Tumor volume for each patient was calculated from pretreatment computed tomograms by summing the products of the cross-sectional tumor area on each CT cut and the interval in millimeters between sequential CT cuts. The mean tumor volume for patients failing radiotherapy was 21.8 cm3, and the mean volume for patients primarily controlled by radiotherapy was 8.86 cm3. Tumor volume significantly predicted disease-free interval (p = .045) and outcome with radiotherapy (p = .02). The study suggests that tumor volume is a significant factor in determining the outcome of primary radiotherapy in advanced laryngeal carcinoma.