Aims and background: To report results of hyperfractionated radiotherapy for T2N0 glottic carcinoma at a single institution after extended follow-up.
Methods: Between 1980 and 1988 at Varese University Hospital, 60 consecutive patients with T2N0 glottic carcinoma received exclusive radiotherapy consisting of 1.5 Gy/fraction twice a day. Treatment gaps during the radiotherapy course were allowed according to individual tolerance. This policy resulted in a wide range of elapsed treatment time: median, 5.7 weeks; range, 3.7-8.9. Median follow-up is 9.8 years.
Results: As a result of dose/time distribution, 16, 20 and 24 patients received an average weekly dose rate of <10 Gy/week, equal to 10 Gy/week or >10 Gy/week, respectively. Mean total dose for each group was 62.8 Gy, 63.7 Gy and 63.8 Gy, respectively. Five-year local-regional control was 69 +/- 6% (95% CI); ultimate local-regional control, including salvage surgery, was 78 +/- 5%. All failures were at the primary site, and no patient developed neck recurrence as first site of failure. The actuarial incidence of grade 2-3 late reactions at 5 years was 42 +/- 6%. Most late toxicity events were grade 2: only 2 patients developed grade 3 reactions and none grade 4. None of the several clinical and treatment-related variables showed any statistically significant impact on local-regional control or late toxicity at univariate and multivariate analysis. In particular, 3-year local-regional control rates were 73 +/- 11%, 84 +/- 8% and 69 +/- 10% for an average weekly dose rate of <10 Gy/week, equal to 10 Gy/week and >10 Gy/week, respectively (not significantly different).
Conclusions: At a very long follow-up, the hyperfractionated regimen tested in the study was shown to be effective and devoid of major complications, provided individual patient acute tolerance is carefully taken into account. Also, time factor did not affect outcome in this series.