High-dose-rate interstitial brachytherapy for mobile tongue cancer: influence of the non-irradiated period.

BACKGROUND It has been demonstrated that the outcome of primary radiotherapy in squamous cell carcinomas of the head and neck is strongly influenced by overall treatment time. The purpose of this study was to evaluate the results of high-dose-rate (HDR) interstitial brachytherapy (ISBT) for early mobile tongue cancer and to examine whether the non-irradiated period affected treatment results. MATERIALS AND METHODS Seventy-one patients with early mobile tongue cancer (T1-T2N0M0) were treated with HDR ISBT alone. The total dose was 54-60 Gy/9-10 fractions/5-9 days. All patients were classified into 4 groups: R0, maximum non-irradiated period (NIP) was less than 24 h (n=16); R1, maximum NIP was from 24 to 48 h (n=24); R2, maximum NIP was from 48 to 72 h (n=26); R3, maximum NIP was from 72 to 96 h (n=5). RESULTS The 3-year local control rate was 94% in R0, 83% in R1, 85% in R2 and 100% in R3. The 3-year overall survival rate was 84% in R0, 92% in R1, 71% in R2 and 80% in R3. There was no significant difference in the local control rate, overall survival rate, or complications among the 4 groups. CONCLUSION In HDR ISBT for early mobile tongue cancer, the non-irradiated period did not affect the treatment results or complications.