Importance of total radiation dose and overall treatment time in T1 early glottic cancer

Background: in this study, we retrospecvely reviewed the treatment outcome of63 paents with t1 early gloc cancer treated with rt alone to determine thetreatment outcome and the prognosc factors affecng local control. materialsand methods: all paents were treated by 6 mv photons with convenonalbilateral fields up to a median dose of 66 gy in 33 fracons. results: the 5-yearlocal control rate and overall survival were 77.7% and 93.1%, respecvely.the total radiaon dose with a cut-off value of 66 gy was a significantprognosc factor for local control. the 5-year local control rate was 54.5% inpaents treated with less than 66 gy compared to 85.7% in paents treatedwith 66 gy or higher dose (p = 0.014). in subgroup analysis, in paents whoreceived 66 gy or higher doses, all recurrences developed in whose overalltreatment me was 49 days or longer, although the stascal significancewas marginal (p = 0.066). conclusion: this study showed that a total dose of 66gy or higher is required for the treatment of t1 gloc cancer, and delivering thetotal dose within 49 days seems important for local control.