Results in irradiation of the in situ carcinomas of the vocal cords.

From 1952 through 1973, 79 patients with the diagnosis of in situ carcinoma and seven with the diagnosis of leukoplakia and/or atypical hyperplasia were treated with irradiation. The staging system was the same as for the invasive squamous carcinomas. The irradiation techniques were also identical to those used for invasive squamous cell carcinomas. The failure rate for the T1 lesions was 11% and 26% for the T2 lesions--in the same range as the failure rates observed for the invasive squamous carcinomas. Only two of the 12 failures were on the initially involved cord. These two facts suggest that most of the failures were not recurrences but were new disease developing on the dysplastic epithelium. There was a delay in the appearance of failure for the in situ carcinomas as compared with that for the invasive squamous cell carcinomas of the supraglottic larynx. Seventy-six percent of the patients have a normal voice.