[Radiotherapy of T1N0 neoplasms of the glottis. Analysis of the parameters that influence local control]

Treatment and tumor-related parameters were reviewed in 176 patients with T1N0 carcinoma of the glottic larynx submitted to primary radiation therapy from 1980 to 1992. Our aim was to analyze local control and treatment-related toxicity. Over-all local control rates at 10 years were 88.3% with irradiation alone and 94.5% after salvage surgery (larynx preservation: 91%). Verrucous histology was a negative factor affecting local control and anterior commissure involvement exhibited only a negative trend but had no statistical significance. Among treatment-related factors, local control was 76.5% after split-course and 91.1% after continuous-course irradiation (p < 0.05). With continuous-course irradiation, the total dose influenced local control only for single of 2 Gy (local control rates were 69% with 60 Gy and 93% at > or = 64 Gy; p < 0.05), but not for single doses of 2.25 Gy and total doses ranging 56.25-65.25 Gy (local control failed in 55 patients). Early and late complications did not increase with single doses > or = 2.25 Gy. Our current policy in T1N0 nonverrucous glottic carcinoma is to use a single fraction of 2.25 Gy and a total dose ranging 56.25-63 Gy according to tumor size, with a continuous course.