Accelerated radiotherapy for T1, 2 glottic carcinoma: Analysis of results with Ki-67 index

Purpose: Hyperfractionated and accelerated radiotherapy without a split was performed to improve the local control probability of early glottic carcin omas. We analyzed the results of this regimen by using the Ki-67 index. Methods and Materials: Over a 12-year period, 85 T1N0M0 glottic cancers and 50 T2N0M0 glottic cancers were treated with conventional fractionation (CF ) from 1984 to 1989 and with accelerated fractionation (AF) since 1990, The CF program consisted of five daily fractions of 2 Gy per week, for a total of 64 Gy, The AF program consisted of 1.72 Gy per fraction, two fractions per day, 5 days a week, for a total of 55 or 58 Gy, The specimens, taken be fore radiotherapy, were immunohistochemically stained with anti-Ki-67 antib ody. Results: The 5-year local control probability for T1 tumors was 79.6 +/- 6. 9% with CF treatment, whereas with AF it was 86.9 +/- 5.6%. For T2 tumors i t was 62.7 +/- 12.2% with CF, whereas it was 74.7 +/- 7.8% with AF. The dif ference between CF and AF did not reach the point of statistical significan ce. However, when T1 tumors had a Ki-67 index lower than 50%, the local con trol rate achieved with AF was significantly better than that with CF (p = 0.018). When the tumors had a Ki-67 index that was 50% or more, there was n o difference in the local control rate between CF and AF, whether they were T1 or T2, The peak mucosal reactions at the larynx and/or hypopharynx were much more severe and appeared at smaller doses and earlier in AF than in C F, The patients with AF showed no severe late complications. Conclusions: AF could not obtain statistically significant improvement in l ocal control probability of T1 or T2 glottic carcinomas. (C) 2000 Elsevier Science Inc.