术前、术后放疗在直肠癌治疗中作用的评估和比较

Evaluation and Comparison of Pre- and Postoperative Radiotherapy in Rectal Cancer

评估和比较辅助性术前、术后放疗在直肠癌治疗中的作用。方法：1988年2月～1995年2月收治经病理证实的直肠癌176例，配合手术分别采用术前单次放疗、术前常规放疗和术后放疗。术前单次放疗组38例，剂量为5Gy，并于放疗后48h内手术；术前40Gy常规放疗组43例，多为临床晚期(T3～4占60.5%)，中位剂量40Gy，放疗后休4周再行手术；术后放疗组95例，以病变晚期和淋巴结阳性为主(T3～4占62.1%，T2～4N＋占81.1%)，采用中位剂量54Gy常规分割，疗程约6周，手术后3～4周开始接受放疗。结果：全部病例平均随访84个月，Kaplan-Meier法计算生存率。术前单次放疗组3年、5年生存率分别为78.9%和50.0%，常规术前40Gy放疗组为67.4%和51.1%；术后放疗组为58.9%和43.1%；3组的3年、5年局部复发率分别为13.1%和23.6%、11.6%和27.9%及23.1%和28.4%。经Logrank检验，结果表明2组术前放疗的3年局部复发率明显低于术后放疗组(P<0.05)，两者的5年局部复发率及3年、5年生存率无明显差异。经χ2检验，术前单次放疗组和术前常规放疗组的急性及远期副反应均明显低于术后放疗组。结论：适当剂量的术前放疗与术后放疗相比，前者具有较高的局部控制率和较低的放疗后副反应。

To evaluate and compare the effects of pre- and postoperative radiotherapy on rectal cancer. Methods: One hundred and seventy-six cases of histologically proved rectal cancer admitted from February 1988 to February 1995, were divided into 3 groups. Group one: 38 patients(T2:68.4%) were treated with a single fraction preoperative radiotherapy, with a tumor dose of 5 Gy; operation was performed within 48 hours. Group two: 43 patients(T3～4:60.5%) were treated by the conventional preoperative radiotherapy regimen with a median tumor dose of 40Gy in 20 fractions, with a daily dose of 1.8～2Gy, followed by surgery within 4 weeks. Group three: 95 patients(T3～4:62.1%,T2～4N＋:81.1%) underwent postoperative radiotherapy with a median tumor dose of 54Gy in 30 fractions, with a daily dose of 1.8Gy, 3～4 weeks after surgery. Results: The 3-yr and 5-yr survival rates were: 78.9% and 50.0% in group one, 67.4% and 51.1% in group two, 58.9% and 43.1% in group three. Local recurrence rates were:13.1% and 23.6% , 11.6% and 27.9%, 23.1% and 28.4% in the 3 groups, respectively. Only the 3-yr local recurrence rate of the two preoperative radiotherapy groups were significantly lower than those of the postoperative radiotherapy group (P<0.05). Conclusions: Compared with the postoperative radiotherapy regimen, preoperative radiotherapy with a proper dosage had better local control and fewer complications.