Can pretreatment computed tomography findings predict local control in T3 squamous cell carcinoma of the glottic larynx treated with radiotherapy alone?

PURPOSE

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

METHODS AND MATERIALS

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.

RESULTS

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 not equal to < .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 (< or = 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).

CONCLUSION

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.