Irradiated volume and arytenoid edema after radiotherapy for T1 glottic carcinoma.

From May 1982 through December 1986, 116 T1 glottic carcinomas were treated with radiotherapy in a prospective randomized study to determine the effect of radiation field size. Patients were treated with a total dose of 60 Gy over six weeks using 4 MV X-ray, wedge filter and shell. Local control rates treated with a field size of 5 x 5 cm2 and 6 x 6 cm2 were 93% and 95%, respectively. Persistent laryngeal edema occurred in 4% of cases treated with 5 x 5 cm2 and 21% with 6 x 6 cm2 (p less than 0.02). The rate of late laryngeal edema was dependent upon the treatment volume. A larger treatment field yielded a higher minor complication rate without improvement of local control rate.