整体调强技术在乳腺癌改良根治术后放疗中的应用

The application of technique as an integrated volume with IMRT for breast cancer after mastectomy

目的:探讨乳腺癌改良根治术后胸壁靶区和锁骨上靶区整体调强计划的剂量学特点以及临床急性放疗反应。方法:146例乳腺癌改良根治术后患者中整体调强计划43例,常规三维适形计划103例。处方剂量均为50 Gy/25次/5周,90%的靶区达到处方剂量;分别对胸壁靶区、锁骨上靶区、正常器官的剂量学特点进行比较,同时观察和随访患者局部皮肤和放射性肺炎的情况。结果:胸壁靶区整体调强计划相比适形接野计划有更好的靶区适形性和均匀性。锁骨上靶区整体调强计划95%处方剂量包含的靶区体积均有明显的提高,靶区适形性和均匀性有显著的改善。危及器官整体调强计划同侧肺V30、心脏V30均低于适形接野计划,而同侧肺V5、心脏V5高于后者,同侧肺V20、Dmean无统计学差异,临床观察Ⅱ级以上放射性皮炎发生率37.7%(55/146),且两组间没有统计学差异,两组均未发生放射性肺炎。结论:在不增加危及器官受量的前提下,应用整体调强技术能明显改善锁骨上靶区的剂量,提高胸壁靶区和锁骨上靶区的剂量适形性和均匀性,值得临床推广应用。

Objective：To discuss dosimetric characteristics and acute clinical radiotherapy effects of integrated volume for chest wall target and supraclavicular target with intensity modulated radiation therapy （IMRT） for breast cancer after mastectomy. Methods： Among 146 cases of patients with breast cancer after mastectomy,there were 43 cases of integrated volume IMRT plan （IMRT group） and 103 cases of general 3D-CRT plan （general group）. Prescription dose was 50 Gy/25 times/5 weeks,and 90% of target area reached prescription dose. Dosimetry characteristics on the chest wall target,supraclavicular target area and normal organ were compared,while observing and following the partial skin reaction and radiation pneumonitis. Results： Compared with general group the plan of integrated volume with IMRT for the chest wall target area resulted in a better target conformal and uniformity, and in the plan of integrated volume with IMRT for supraclavicular target area,95% prescription dose containing the target volume, conformal and uniformity for the target region were increased obviously, and in the plan of integrated volume with IMRT for breast cancer for the normal organ,the V30 of the ipsilateral lung and V30 of the heart were decreased,while the V5 of the ipsilateral lung and heart were increased. There was no statistical difference of V20 and Dmean of the ipsilateral lung. The occurrence rat of the radiation dermatitis was 37.7%（55/146） and no statistical difference was observed between two groups. None radiation pneumonitis occurred. Conclusion：The plan for integrated volume with IMRT for breast cancer can improve the dose of supraclavicular target significantly by the quantity under the premise for organ at risk,and improve conformal and uniformity of the dose for chest wall target area and supraclavicular target volume.