Abstract
Math Eq: To determine if pretreatment computed tomography findings can predict local control in T3 squamous cell carcinoma of the glottic larynx treated with radiotherapy alone.

Math Eq: Twenty-nine patients with previously untreated T3 squamous cell carcinoma of the glottic larynx were treated for cure with radiotherapy alone; all had a minimum 2-year follow-up. High-quality pretreatment computed tomography scans were retrospectively reviewed by a single head and neck radiologist for tumor involvement of various anatomic subsites within the larynx, and total tumor volumes were calculated for 18 of the most recent patients using a computer digitizer. A tumor score was calculated and assigned to each primary lesion depending on the extent of laryngeal spread.

Math Eq: A significant decrease in the local control rate was observed for cancers involving the face of the arytenoid (11 of 20 [55%] vs. 9 of 9 [100%]; p = .02), or the paraglottic space at the false vocal cord level (7 of 16 [44%] vs. 13 of 13 [100%]; p ≠ < .01). Tumors assigned a high tumor score (6, 7, or 8) had a significantly decreased rate of local control with radiation therapy when compared with tumors assigned a low tumor score (≤ 5): 1 of 7 (14%) vs. 19 of 22 (86%) (p = .01). Total tumor volume also significantly correlated with the rate of tumor control. For tumors measuring 3.5 cm3 or less, local control was achieved in 11 of 12 patients (92%), whereas for tumors greater than 3.5 cm3, local control was achieved in 2 of 6 patients (33%) (p = .02).

Math Eq: Pretreatment computed tomography scans can contribute significantly to the treatment decision for patients with T3 glottic carcinoma and can define a subset of patients with an excellent chance of being cured with preservation of a functional larynx after treatment with radiotherapy alone.