目的：分析直腸癌手術前同步化學及放射治療的長期結果。材料與方法：本研究分析自2004 年11 月到2006 年8 月期間，32 位病理診斷為腺癌的直腸癌病患。所有的病人都接受手術前同步化學及放射治療，放射治療技術使用強度調控放射治療，劑量為50.4 Gy ，A 組的病人化學藥使用5FU ，B 組的病人則使用5FU 加上口服UFUR。14 位病人為A 組，18 位病人為B 組。手術在放射治療後4~6 週進行。本研究主要分析治療後分期下降，術後病理報告無存活之癌細胞，及可行肛門保留手術的比例。其次分析總存活率，復發率及無病存活率。結果：自診斷後開始計算，經過中位數44 個月（15~59 個月）的追蹤，病人的治療後分期下降，術後病理報告無存活之癌細胞，及肛門保留手術率分別為46.9%, 12.5% 和72.7% 。分別來看，A 組達到治療後分期下降和術後病理報告無存活之癌細胞為35.7% 和7.1%；B 組達到治療後分期下降和術後病理報告無存活之癌細胞為55.4% 和16.7% 。有4 位達到術後病理報告無存活之癌細胞之病人至研究結束為止沒有局部復發和遠處轉移。全部病人的四年總存活率及復發率分別70.3% 和9.6% 。分別來看，A 組的復發率為11.1% ，而B 組的復發率為5.6% 。在治療副作用方面，B 組有較強的血液副作用。而在腸胃道的副作用方面，二組相似。手術相關的副作用二組也是相似。結論：強度調控放射治療可以減少腸道之副作用。手術前化學合併放射治療可達到較高的肛門保留比率及較低的復發率。

Purpose : To investigate clinical outcome, especially anal sphincter preservation and local recurrence rate, of locally advanced rectal cancer after neoadjuvant chemoradiotherapy. Materials and Methods : From November 2004 to August 2006, a total of 32 patients with adenocarcinoma of rectal cancer, clinical stage T3-4, N0-2, were enrolled in this retrospective study. All patients received neoadjuvant chemoradiotherapy which consisted of intensity-modulated radiotherapy (50.4 Gy) and was concomitant with bolus 5-FU (group A) or bolus 5-FU plus oral UFUR (group B). Fourteen patients were enrolled in group A; 18 patients were categorized as group B. Operation was performed 4~6 weeks thereafter. The primary endpoints were downstaging, pathological complete response (pCR) and sphincter preservation rate. The secondary endpoints were overall survival (OS), local recurrence rate (LRR), and disease-free survival (DFS). Results : The median follow-up period for all patients was 44 months from the date of diagnosis, ranging from 15 to 59 months. The downstaging, pCR and sphincter preservation rate of all patients were 46.9%, 12.5% and 72.7%, respectively. There was no significant difference between group A and B in tumor downstaging or pCR. The 4 patients who achieved pathological complete response did not experience local recurrence or distant metastasis at the end of this study. The 4-year OS, LRR and DFS of all patients were 70.3%, 9.6% and 74.5%. No significant difference could be recorded between groups A and B in OS, LRR and DFS. Group B had more significant hematological toxicity. Grade 2 or greater GI toxicity was similar in both groups. Surgery related complications were similar in both groups. Conclusion : Neoadjuvant chemoradiotherapy using IMRT with concomitant 5-FU based chemotherapy achieved good results for sphincter preservation and local control in locally advanced rectal cancer.