Radiotherapy for early glottic carcinoma (T1N0M0): Results of prospective randomized study of radiation fraction size and overall treatment time

Purpose: To investigate in a prospective randomized study the effect of radiation fraction size and overall treatment time on the local control of early glottic carcinoma. Methods and Materials: Between December 1993 and December 2001, 180 patients with early glottic carcinoma (T1N0M0) were treated at our department. The patients were randomly allocated to either treatment arm A (radiation fraction size 2 Gy, n = 89) or B (2.25 Gy, n = 91). The total radiation dose administered was 60 Gy in 30 fraction within 6 weeks for minimal tumors (two-thirds of the vocal cord or less) or 66 Gy in 33 fractions in 6.6 weeks for larger than minimal tumors (more than two-thirds of the vocal cord) in Arm A and 56.25 Gy in 25 fractions within 5 weeks for minimal tumor or 63 Gy in 28 fractions within 5.6 weeks for larger than minimal tumors in Arm B. Results: The 5-year local control rate was 77% for Arm A and 92% for Arm B (p = 0.004). The corresponding 5-year cause-specific survival rates were 97% and 100% (no significant difference). No significant differences were found between these two arms in terms of rates of acute mucosal reaction, skin reactions, or chronic adverse reactions. Conclusion: Use of 2.25-Gy fractions with a shorter overall treatment time for Arm B showed superior local control compared with conventional use of 2-Gy fractions for Arm A without adverse reactions from the greater fraction. (c) 2006 Elsevier Inc.