早期乳腺癌保乳术后瘤床区同步加量IMRT的剂量学及疗效分析

Dosimetric character and curative effect of postoperative radiotherapy with tumor bed boost simultaneously using IMRT in early breast cancer patients

目的前瞻性临床观察乳腺癌保乳术后瘤床同步加量放射治疗的剂量分布、不良反应、美容效果及疗效。方法选取2012~2013年43例Ⅰ~Ⅱ期行保乳手术加前哨淋巴结活检和/或腋窝淋巴结清扫术的乳腺癌患者纳入研究。保乳术后进行术后辅助放射治疗,并予以瘤床区同步加量治疗。采用调强放疗技术(IMRT),计划靶区(PTV)50Gy/25f,瘤床加量区(PTV boost)60Gy/25f/2.4Gy/fx。观察放疗计划剂量学特征、临床副反应、放疗前后美容效果及疗效。结果采用调强放疗技术的术后瘤床同步加量放射治疗具有良好的靶区剂量分布、适形度指数(CI)及均匀度指数(HI)。1度皮肤反应发生率53.49%,2度为41.86%,3度为4.65%,无4度皮肤反应者;1级放射性肺炎发生率30.23%,2级为9.16%,未出现3~4级放射性肺炎;1级和2级上肢水肿发生率分别为18.60%和4.65%;放疗前评估美容效果优良率为93.02%,放疗后为86.04%;3年局部无复发生存率(LRFS)为97.67%,3年的总体生存率(OS)为95.35%。结论瘤床同步加量放射治疗乳腺癌缩短了治疗周期,调强技术的应用可以保证剂量分布均匀度及适形度,急性及远期副反应风险较低,3年的DFS及OS理想,美容效果评价满意,具有可靠的安全性及疗效。

Objective To observe the dose distribution, adverse reaction, cosmetic effect and curative effect of postoperative radiotherapy using tumor bed boost simultaneously for breast cancer patients after breast conserving surgery. Methods 43 patients with Ⅰ to Ⅱ breast cancer accepted breast-conserving surgery and sentinel lymph node biopsy± axillary lymph node sweeping surgery were involved. Intensity-modulated whole breast irradiation （WBI） ＋ supraclavicular/axillary area radiation were conducted with tumor bed boost simultaneously. A dose of 50Gy/25f was delivered to planning target volume （PTV）, and 60Gy/25f/2.4Gy/fx was delivered to tumor bed boost area （PGTV）. Radiotherapy dosimetry characteristics, clinical adverse reaction, the cosmetic effect and curative effect were observed before and/or after radiotherapy. Results The CI, HI and dose distribution were satisfied using IMRT technique. 53.9% patients developed grade Ⅰ skin injury, 41.86% for grade Ⅱ , 4.65% for grade Ⅲ , and no grade Ⅳ skin injury was found. Grade Ⅰ lung injury was 30.23%, 9.16% for grade Ⅱ , and no grade Ⅲ or grade Ⅳ lung injury was found. Grade Ⅰ and grade Ⅱ . The upper limb lyrnphedema were observed in 18.6 % and 4.65 % patients respectively. In cosmetic effect evaluation. 93.02% patients scored good and very good before radiation therapy, and the percentage changed to 86.04% when i year after radiation therapy. The 3-year LRFS was 97.67%, and 3-year OS 95.35%. Conclusion In this research, the simultaneous tumor bed boost postoperative radiation therapy shows satisfied CI and HI when IMRT technique is supplied, and much more shorter treatment cycle compared with the sequential tumor bed boost. Its acute and long-term side effects is low msked, and exhibits fine cosmetic effect. 3-year LRFS and 3-year OS which are no less than those in previous reports.