Hyperfractionated accelerated radiotherapy for T1,2 glottic carcinoma. Consideration of time-dose factors.

BACKGROUND AND PURPOSE: Hyperfractionated accelerated radiotherapy without a split (AF) has been performed to improve the local control probability of early glottic carcinomas since 1990 in the authors' institution. Here, they report their experience treating early glottic cancer patients with AF in a single institution who have a long follow-up period.

PATIENTS AND

METHODS

131 T1 N0 M0 glottic cancers and 65 T2 N0 M0 glottic cancers were treated with conventional fractionation (CF) from 1984 to 1989 and with AF since 1990. CF consisted of five daily fractions of 2 Gy per week, to a total dose of 64 Gy. AF consisted of 1.72 Gy per fraction, two fractions per day, 5 days a week, to a total dose of 55 or 58.5 Gy.

RESULTS

The 5-year local control probability for T1 tumors was 94% with 58.5 Gy and 87% with 55 Gy of AF, whereas it amounted to 80% with CF. For T2 tumors, it was 56% with 58.5 Gy and 68% with 55 Gy of AF, whereas it amounted to 64% with CF. The data of T2 should be evaluated with caution due to the small number of patients. Patients with AF had more severe mucosal reactions but no severe late reactions.

CONCLUSION

AF significantly improved the local control rates for T1 glottic cancer.