目的：探討原發性頭頸部腫瘤患者接受手術後放射治療時，各項時間因素對於局部控制率的影響。材料與方法：自1996至2004年，共有141位接受根除性手術的頭頸部癌症病患，至本科接受手術後放射治療。若是手術後因為復發才接受放射治療的病人，或只接受切片檢查的病人則不包括在內。照射劑量、整體治療時間、治療前等待時間的中值分別為61.2格雷，48天，與34天，其中有277%的病人在治療中沒有中斷，有20.6%的病人治療中斷大於5天。結果：所有病人追蹤時間中值為14個月，無復發存活(recurrence-free Survival)時間中值為34個月，其中有61位病人(43.3%)有復發的現象。以單變數分析，治療前等待時間小於等於30天的病人有較佳的局部控制率(p=0.0328)，但是多變數分析沒有顯著意義；整體治療時間與治療中斷時間的長短對局部控制率沒有影響。結論：對於接受手術後放射治療的頭頸部腫瘤患者而言，治療前等待時間大於30天是一個不利因子；雖然在本研究中整體治療時間與治療中斷時間並沒有顯著意義，我們仍應盡量縮短治療前的等待時間，並避免治療中斷。

Purpose: To study the locoregional tumor control in postoperative radiotherapy of head-and-neck cancer in relation to the duration of the surgery-radiotherapy interval, overall radiation treatment time (OTT), and treatment gap. Methods and Materials: This retrospective study included 141 patients with cancer of head and neck, treated with surgery first, followed by postoperative irradiation between 1996 and 2004. The patients who had recurrence before radiotherapy or only received biopsy were not included. The median of the total radiation dose, surgery-radiotherapy interval, and the overall treatment time were 61.2 Gy, 34 days, and 48 days respectively. No interruption during radiotherapy (except for weekend breaks) was found in 27.7% of patients. Twenty point six percent of patients had more than 5 days of gap. Results: The median duration of follow-up was 14 months. The median recurrence-free survival time was 34 months. Recurrence developed in 61 patients (43.3%). Increased surgery-radiotherapy interval to more than 30 days was significantly related to a decrease in recurrence-free survival (RFS) (p=0.0328). However, the duration of OTT and treatment gaps did not influence RFS significantly. Conclusions: In our study, increased surgery-radiotherapy interval to more than 30 days would cause an adverse effect. Although the overall treatment time and treatment gap did not affect RFS significantly, we should do our best to shorten the surgery-radiotherapy interval and avoid the treatment gaps.