The significance of laryngeal edema following radiotherapy of carcinoma of the vocal cord.

Laryngeal edema persisting for more than three months following radiotherapy developed in 38 of 247 (15.4%) patients irradiated for carcinoma of the vocal cord. In 17 (44.7%) of these patients, the laryngeal edema was associated with persistent or recurrent disease, although only 25.4% of the patients with uncontrolled disease had laryngeal edema. The incidence of laryngeal edema was 13.1% for T1 disease, 23.8% for T2, and 21.4% for T3 and T4 disease. It increased significantly with increase of minimum tumor dose greater than or equal to 7000 rads or with NSD greater than 1900 ret, being 46.2% with minimum tumor dose greater than or equal to 7000 rad and 13.7% with minimum tumor dose less than 7000 rad and 43% with NSD greater than 1900 ret and 17% with NSD less than or equal to 1900 ret. It also increased with increase of field size, being 13.4% with field sizes less than 6.0 x 6.0 cm2, and 24.4% with field sizes greater than or equal to 6.0 x 6.0 cm2. When laryngeal edema is progressive and unresponsive to conservative measures, multiple biopsies should be performed to establish the presence of persistent or recurrent disease before salvage surgery is attempted. However, if it is mild, stable, no visible recurrence develops, and especially if it is limited to the arytenoids, no biopsy should be attempted because of the risk of inducing laryngeal necrosis.