Radiation therapy in T1-T2 glottic carcinoma: influence of various treatment parameters on local control/complications.

PURPOSE

To evaluate the influence of various treatment parameters on local control as well as complications in T1 and T2 glottic carcinomas.

METHODS AND MATERIALS

Between 1975 and 1989, 676 patients with early glottic carcinoma (460 T1 and 216 T2) received curative radiation with three different treatment regimens, as follows: Regimen 1-50 Gy/15 Fr/3 weeks (3.33 Gy/daily) for 192 patients; Regimen 2-60-62.5 Gy/24-25 Fr/5 weeks (2.5 Gy/daily) for 352 patients; and Regimen 3-55-60 Gy/25-30 Fr/5-6 weeks (2-2.25 Gy/daily) for 132 patients.

RESULTS

The local control at 10 years was 82% and 57% for T1 and T2 lesions respectively (p = 0.0). For the T1N0M0 group, field size had significant impact on local control with both univariate (p = 0.05) and multivariate (p = 0.03) analysis. For T2N0M0, group field size (p = 0.03) as well as registration year (p = 0.016) were significant in univariate analysis whereas only field size remained significant on multivariate analysis. Persistent radiation edema was noted in 146 (22%) patients and was significantly worse with larger field size (p = 0.000) but not related to different treatment regimens.

CONCLUSION

The shorter fractionation schedule had comparable local control, without increased complications in comparison to the protracted schedule and is best suited for a busy department.