Early-stage squamous cell carcinoma of the glottic larynx managed with radiation therapy

Between January 1975 and December 1985, 45 patients with carcinoma in situ or invasive squamous cell carcinoma of the glottic larynx received radiation therapy at the Mayo Clinic. Local control in the entire group of 45 patients was 84% (in 6 of 6 with carcinoma in situ and in 32 of 39 with invasive cancers). Three of seven patients (43%) with local recurrences underwent successful larynx-preserving surgical procedures; thus, the rate of laryngeal preservation was 91%. In our study of several treatment factors, including the duration of treatment, type of treatment (continuous course versus split course), photon energy (60Co versus 4-MV photons versus 6-MV photons), total dose, and dose per fraction, we found that only total dose of 6,300 cGy or more was associated with significantly improved local control (in 35 of 38 patients [92%]). Two patients (4%) died of uncontrolled delayed nodal metastases, one of which was preceded by a local recurrence. Severe laryngeal edema developed in two patients, associated with recurrent glottic carcinoma in one of them. No larynx was lost because of complications. In our current treatment recommendations, patients receive a total dose of 6,300 cGy in 28 fractions of 225 cGy each, administered in a continuous course with use of 6-MV photons.