Purpose: To compare the treatment results and toxicity of continuous accelerated hyperfractionated (CAHF) and late-course accelerated hyperfractionated (LCAF) radiotherapy (RT) for esophageal carcinoma.
Methods and materials: Between August 1996 and March 1999, 101 patients with squamous cell carcinoma of the esophagus were randomized into two groups: 49 to the CAHF group and 52 to the LCAF group. Patients in the CAHF group received RT at 1.5 Gy/fraction b.i.d. (6-h interval), 5 d/wk, to a total dose 66 Gy in 44 fractions during 4.4 weeks. The patients in the LCAF group received conventional fractionation RT, 1.8 Gy/fraction, to a dose of 41.4 Gy in 23 fractions during 4.6 weeks, followed by accelerated fractionation RT using reduced fields, b.i.d., at 1.5 Gy/fraction, with a minimal interval of 6 h between fractions. The total dose was 68.4 Gy in 41 fraction during 6.4 weeks. Patient age, gender, performance score, diet, lesion location, lesion length, stage, and fractionation (CAHF or LCAF) were entered into the univariate and multivariate analyses.
Results: All patients finished the treatment course, except for 1 patient in the CAHF group because of severe acute esophagitis. The rate of Grade I, II, and III acute bronchitis was 18.4% (9 of 49), 30.6% (15 of 49), and 8.2% (4 of 49) in the CAHF group and 13.5% (7 of 52), 21.2% (11 of 52), and 3.8% (2 of 52) in the LCAF group, respectively. However, the difference between the two groups was not statistically significant (p = 0.084). The rate of Grade I, II, III, and IV acute esophagitis was 6.1% (3 of 49), 32.7% (16 of 49), 46.9% (23 of 49), and 14.3% (7 of 49) in the CAHF group and 26.9% (14 of 52), 32.7% (17 of 52), 7.7% (4 of 52), and 1.9% (1 of 52) in the LCAF group, respectively. The difference was statistically significant (p < 0.001). The local control rate at 1, 2, and 3 years was 88.7%, 83.9%, and 55.9% in the CAHF group and 80.7%, 71.4%, and 57.1% in the LCAF group, respectively (p = 0.1251). The 1-, 2-, and 3-year survival rate was 79.6%, 51.6%, and 37.6% in the CAHF group and 80.0%, 57.6%, and 41.2% in the LCAF group, respectively (p = 0.5757). Multivariate analysis showed that age and lesion length were independent significant prognostic factors for local control rate, and age was for the overall survival rate. The fractionation schedule had no significant prognostic effect.
Conclusion: CAHF and LCAF result in similar 1-, 2-, and 3-year local control and survival rates. CAHF resulted in more severe acute esophagitis and may be less well tolerated than LCAF. The treatment results after the CAHF and LCAF regimens were better than those of historical conventional RT.