左侧乳腺癌保乳术后调强放疗与常规放疗参数比较

Parameter comparison between intensity modulated radiation therapy and conventional radiotherapy after breast-conserving surgery due to left breast cancer

目的研究左侧乳腺癌保乳术后调强放疗与常规放疗靶区内剂量均匀性、心肺照射剂量和体积的差异。方法选取我院2013年3月-2014年3月行左侧乳腺癌保乳术的20例患者，术后给予患者50Gy／25f放疗，同时给予适当能量电子线补量10Gy／5f，总剂量为60Gff30f。并为每例患者设计两组放疗计划，分别为常规计划（CRT）和三维适形调强放疗计划（IMRT），两组放疗先后进行。比较两种计划在靶区内剂量均匀性心脏照射剂量和体积的差异。结果调强放疗与常规放疗中的Prv为V107和V95时相比较。差异有统计学意义（P〈0．05）；调强放疗与常规放疗中的P1V为V110和V115时相比较，常规放疗高于调强放疗，差异无统计学意义（P〉0．05）；调强放疗的均匀指数优于常规放疗的均匀指数，差异有统计学意义（P〈0．05）；在肺脏受量上，调强放疗与常规放疗的V40、V30、V20、V10比较，差异均有统计学意义（P〈0．05）；在心脏受量上，调强放疗与常规放疗的V30、V5比较，差异均有统计学意义（P〈0．05）。结论左侧乳腺癌保乳术后给予调强放疗明显优于常规放疗，调强放疗可优化靶区分布、提高剂量的均匀性，降低患者心肺照射剂量。

Objective To explore the differences in dose uniformity in target region, and cardiopulmonary radiation dose and volume between intensity modulated radiation therapy （IMRT） and conventional radiotherapy （CRT） after breast-conserving surgery due to left breast cancer. Methods 20 patients treated by breast-conserving surgery due to left breast Cancer in our hospital from March 2013 to March 2014 were selected. After surgery, each patient was given radiotherapy of 50 Gy/25 f, as well as energy electron beam irradiation of 10 Gy/5 f, in a total dose of 60 Gy/30 f. Both CRT and IMRT were designed for each patient and were conducted successively. Differences in dose uniformity in tar- get region, and cardiopulmonary radiation dose and volume between two therapies were compared. Results There were significant differences at V107 and V95 of PTV between IMRT and CRT（P〈0.05）. At V110 and V115 of PTV, CRT was higher than IMRT, but with no significant difference （P〉0.05）. The index of uniformity in IMRT was superior to that of CRT （P〈O.05）. There were significant differences at V40, V30, V20, and V10 in pulmonary radiation dose between IM- RT and CRT （P〈0.05）. There were significant differences at V30 and V5 in cardiac radiation dose between IMRT and CRT（P〈0.05）. Conclusion IMRT has significant advantages over CRT after breast-conserving surgery due to left breast cancer, which can optimize the distribution of target region, improve uniformity of radiation dose, and reduce cardiopul- monary radiation dose.