Ⅱa期宫颈癌术后阴道残端及宫旁组织同步加量放疗的剂量学及毒副反应研究

摘要

Objective To analyze the dosimetry and acute toxicity in postoperative stage Ⅱa cervical cancer patients with simultaneous integrated boost intensity modulated radiotherapy.Methods 9 postoperative cases with stage Ⅱa cervical cancer received simultaneous integrated boost intensity modulated radiotherapy for stump vaginal and parametrial tissues (study group).These patients were compared with 20 patients of postoperative stage Ⅰ b and Ⅱ a cervical cancer that received conventional radiotherapy(control group).Dosimetry and acute toxicity were compared between the two groups.Results The dose of vaginal stump and parametrial tissue were significantly increased in study group than that of the control group (P ＜ 0.05).The V20,V30,V40 of the small bowel significantly decreased in the study group,comparing with the control group (P ＜ 0.05).The average dose of the small intestine was significantly lower in the study group than that in the control group (P ＜0.05).The V40 of bladder,sigmoid colon and rectum in the study group was significantly lower than that in the control group (P ＜ 0.05).There was no significant difference between the two groups in the mean dose of bladder,sigmoid colon and rectum (P ＞ 0.05).The acute radiation enteritis,acute radiation cystitis and bone marrow suppression in the study group were lighter than that in the control group.Conclusion Without increase of the acute toxicity and side effects,the dose of vaginal stump and parametrial tissue can be increased in postoperative stage Ⅱ a cervical cancer patients by using integrated boost intensity modulated radiotherapy.%目的 探讨采用调强放疗(intensity modulated radiation therapy,IMRT)技术对Ⅱa期宫颈癌术后阴道残端及宫旁组织同步加量的剂量学可行性,并评估急性毒副反应. 方法 选取9例Ⅱa期宫颈癌根治术后行IMRT放疗的患者作为研究组,行阴道残端及宫旁组织同步加量;同时期宫颈癌Ⅰb～Ⅱa期根治术后行普通放疗的患者20例为对照组.评估研究组及对照组计划靶区及危及器宫的剂量,并比较二组的急性毒副反应发生率. 结果 采用IMRT技术能显著提高术后阴道残端及宫旁组织剂量(P＜0.05).研究组小肠接受20 Gy、30 Gy、40 Gy的受照射体积比对照组显著下降(P＜0.05),小肠接受的平均剂量也比对照组明显下降(P＜0.05).研究组膀胱、乙状结肠、直肠接受40 Gy的受照射体积比对照组显著下降(P＜0.05),两组膀胱、乙状结肠、直肠平均剂量无显著差异(P＞0.05).分析二组的急性毒副反应发生率,发现研究组急性放射性肠炎、急性放射性膀胱炎、骨髓抑制的程度均较对照组要轻. 结论 IMRT技术在剂量学上有危及器宫的保护优势,能在不增加毒副反应的前提下,有效地提高Ⅱa期宫颈癌术后阴道残端及宫旁组织的剂量.