Early-stage glottic cancer: importance of dose fractionation in radiation therapy

The treatment results in 85 patients with T1N0M0 squamous cell carcinoma of the glottic larynx who were treated with primary radiation therapy were reviewed to analyze for local control. After a minimum follow-up period of 2 years, 13 patients had local recurrence of disease, which yielded a local control rate of 84.7%. Local control was then reassessed as a function of substages (T1a and T1b) and dose fractionation. No difference in local control was seen in T1a and T1b neoplasms. However, after undergoing standard once-a-day fractionation, patients treated with fractions of 200 cGy had a local control rate of 96%, while those receiving 180 cGy had a local control rate of 79% (P = .05). Mean total dose for each patient group was comparable, and the median number of days of treatment interruption was the same for both groups. These data corroborate the recent findings of other authors regarding the importance of fraction size in facilitating local control of early-stage glottic cancer.