中文摘要：

目的 评估早期乳腺癌保乳术后全乳逆向IMRT对腋窝Ⅰ、Ⅱ、Ⅲ站及前哨淋巴结区域的剂量覆盖情况.方法 回顾分析2008-2012年间在复旦大学附属肿瘤医院接受保乳手术及前哨淋巴结活检术的40例乳腺癌患者临床资料.术后全乳逆向IMRT处方剂量为50 Gy分25次.按照RTOG标准及术中放置钛夹的位置勾画腋窝Ⅰ、Ⅱ、Ⅲ站及前哨淋巴结区域,并分析相应区域受量.结果 腋窝Ⅰ、Ⅱ、Ⅲ站淋巴结的平均剂量分别为（33.0±7.5）、（17.9±11.3）、（7.3±6.6）Gy,V9s分别为（29.9±17.7）％、（9.0±14.5）％、（0.1±0.3）％.所有前哨淋巴结均位于第Ⅰ站腋窝淋巴结区域,前哨淋巴结的平均剂量为（43.0±10.0） Gy,58％ （19/33）的平均剂量＞45 Gy.结论 采用逆向IMRT照射乳腺时,腋窝Ⅰ、Ⅱ、Ⅲ站淋巴结受量有限,对前哨淋巴结微转移且未清扫腋窝者应充分考虑这一因素.

英文摘要：

Objective To evaluate the dose coverage of axillary levels Ⅰ-Ⅲ and the sentinel lymph node （SLN） area by multi-field inverse-planned intensity-modulated radiotherapy （IMRT） for whole breast irradiation in patients with early breast cancer after breast-conserving surgery.Methods A retrospective analysis was performed on the clinical data of 40 patients with early breast cancer who underwent breastconserving surgery and SLN biopsy in Fudan University Shanghai Cancer Center from 2008 to 2012.After surgery,inverse-planned IMRT for whole breast irradiation was performed at a dose of 50 Gy/25 fractions.The axillary levels Ⅰ-Ⅲ were delineated according to the RTOG criteria,and the SLN CTV was defined as 2 cm in diameter around the clip.Dose-volume parameters were used to calculate the dose distribution of these lymph node areas.Results The mean doses delivered to axillary levels Ⅰ,Ⅱ,and Ⅲ were （33.0 ± 7.5） Gy,（17.9 ± 11.3） Gy,and （7.3 ±6.6） Gy,respectively.The percent volumes receiving at least 95％ of the prescribed dose for axillary levels Ⅰ,Ⅱ,and Ⅲ were （29.9 ± 17.7） ％,（9.0 ± 14.5） ％,and （0.1 ±0.3） ％,respectively.All SLNs were located in axillary level Ⅰ area; the mean dose received by the SLN area was （43.0 ± 10.0） Gy,and 58％ （19/33） of SLNs received a dose greater than 45 Gy.Conclusions The multi-field inverse-planned IMRT offers a limited dose coverage to axillary levels Ⅰ-Ⅲ in patients receiving inverse-planned IMRT for whole breast irradiation.For those patients with SLN micrometastases and without axillary lymph node dissection,we need to keep an eye on the dose coverage of the axillary area.