低位直肠癌术前加速放疗的临床意义

Clinical characteristics of low rectal carcinoma with preoperative 30 Gy radiation

目的 观察低位直肠癌术前放疗的临床病理变化及意义.方法 对30例已行术前30 Gy（3Gy/次,2次/d,前后野交替,间隔6 h）生物效应等同于常规放疗40Gy的低位直肠癌患者进行术后病理变化分析;直肠镜观察放疗前后直肠肿块的肉眼变化、放疗后手术标本的病理形态学特征.结果 放疗后直肠镜仅见小的病灶、肿块缩小和无明显变化者分别为7例（23.3%）、16例（53.3%）和7例（23.3%）.放疗患者按直肠癌组织学退变的分级标准（RCRG）分为Ⅰ级8例（26.7%）、Ⅱ级15例（50.0%）、Ⅲ级6例（20.0%）.结论 术前30 Gy加速放疗可使大多数直肠癌瘤体缩小,使癌组织坏死,癌组织和间质产生纤维变性,降低肿瘤分期,有利于肿瘤的切除;对低位直肠癌保肛手术具有积极的作用.

Objective To observe the clinical pathological changes lower rectal carcinoma after preoperative radiation.Methods Thirty cases of rectal carcinoma underwent preoperative radiotherapy at a dose of 30 Gy.Gross size of the tumors was measured and histological changes were analyzed before and after radiation.Results The rates of complete regression,partial regression and no response to radiation of the tumors were 23.3%.53.3%and 23.3%.Significant tumor regression RCRG Ⅲ wag seen in 6 cages （20.0%） after radiotherapy.while partially tumor regression RCRG Ⅱ was seen in 15 cases （50.0%）. Conclusion Preoperative radiation at a dose of 30 Gy on lower rectal carcinoma induces degeneration and necrosis of the tumor cells with complete or partial regression in most cases.Necrosis,fibrosis and thickening of vascular intima in the rectal cancer tissue after radiotherapy is more frequent than those without radiotherapy.It may be the potential reason for increased resection rate and sphincter saving after radiotherapy. It hag a great significance for sphincter-preservation surgery in this group of rectal carcinomas.