目的：探讨新辅助化疗结合三维适形放疗在晚期不可手术切除直肠癌转化治疗中的应用效果。方法：选取2008年1月—2013年6月收治的56例不可切除的直肠癌患者（伴肝转移12例），30例作为观察组，使用新辅助化疗加三维适形放疗；26例作为对照组，采用新辅助化疗加常规放疗。比较两组患者治疗后可切除转化率、术后生存状态、不良反应和近期并发症情况。结果：在治疗16周时观察组可切除转化率明显高于对照组（60.0% vs. 26.9%，P=0.013）；与对照组比较，观察组无疾病进展生存期及总生存期均明显延长（P=0.046，P=0.029）；两组不良反应及近期并发症发生情况差异无统计学意义（均P>0.05）。结论：新辅助化疗结合三维适形放疗可明显提高不可手术切除直肠癌的可切除转化率，延长患者的生存期且不增加不良反应和与并发症的发生率。
Neoadjuvant chemotherapy plus three-dimensional conformal radiation in conversion therapy for unresectable advanced rectal cancer
Objective: To determine the efficacy of neoadjuvant chemotherapy combined with three-dimensional (3D) conformal radiation in conversion therapy for unresectable advanced rectal cancer. Methods: Fifty-six patients with unresectable advanced rectal cancer (12 patients with liver metastases) admitted from January 2008 to June 2013 were selected. Of the patients, 30 cases assigned to observational group received neoadjuvant chemotherapy plus 3D conformal radiation therapy, and 26 cases, serving as control group, underwent neoadjuvant chemotherapy and conventional radiation therapy. The conversion rate to resectability, postoperative survival, adverse reactions and incidence of complications after treatment between the two groups of patients were compared. Results: The conversion rate to resectability in observation group was significantly higher than that in control group at 16 weeks of treatment (60.0% vs. 26.9%, P=0.013); both progression-free survival and overall survival in observation group were significantly prolonged compared with control group (P=0.046, P=0.029); the incidence of adverse reactions and short-term complications between the two groups showed no significant difference (all P>0.05). Conclusion: Neoadjuvant chemotherapy combined with 3D conformal radiation therapy can effectively increase the conversion rate to resectability for unresectable rectal cancer, and prolong survival time of the patients without increasing the occurrence of adverse reactions and complications.