Radiotherapy for carcinoma-in-situ of the glottic larynx

To describe the long-term results of radiotherapy as treatment for carcinoma-in-situ of the glottic larynx.

Twenty-nine patients with a histologic diagnosis of carcinoma-in-situ (CIS) of the true vocal cord were treated in the Department of Radiation Oncology at Stanford University Medical Center over a 32-year period from 1958-1990. Twenty patients were treated at the time of initial diagnosis following biopsy only (12) or vocal cord stripping (8) and the remainder were referred for treatment of recurrent CIS following one or more prior surgical procedures. Treatment was delivered with megavoltage equipment to a total dose of 53-66.5 Gy (mean 62 Gy) in 180-250 cGy fractions. The mean follow-up time is 10 years, with a range of 2-27 years.

Two patients relapsed locally. One patient had recurrent CIS 5 months after radiotherapy and was salvaged with vocal cord stripping. The other developed microinvasive squamous cell carcinoma and underwent total laryngectomy. The actuarial freedom from local relapse and overall survival at 10 years are 92% and 64%, respectively. No local failures occurred more than 5 years after treatment. Late complications from radiotherapy were rare, and voice quality was good-to-excellent in 90% of patients. The actuarial risk of a second aerodigestive tract malignancy is 11% at 10 years.

Radiation therapy is an effective and safe treatment modality for carcinoma-in-situ of the glottic larynx. Long-term local control is achieved in approximately 90% of patients with 75% having normal voice.